EPA-660/2-74-006 A p r i l 1974

WASTEWATER ABATEMENT IN CANNING VEGETABLES

BY IQB BLANCHING

Daryl B. Lund U n i v e r s i t y of Wisconsin

Madi son Wisconsin

Grant No. S-801484 Program E l ement 1 BB037

P r o j e c t O f f i c e r

M r . Haro ld Thompson P a c i f i c Northwest Environmental Research Laboratory

Corval1 i s Oregon 97330

Prepared f o r OFFICE OF RESEARCH AND DEVELOPMENT

U.S. ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D. C. 20460

For sale by the Superintendent of Documents, U.S. Governmeiit Printing Office, Washington, D.C. 20402 -Price $1.25

ABSTRACT

This r e p o r t p re sen t s t he r e s u l t s of a s tudy on t h e e f f i c a c y of a new blanching system, Indiv idua l Quick Blanch (IQB), a s appl ied t o vege tab les p r i o r t o canning. Peas, corn, l i m a beans, green beans, po ta toes , c a r r o t s and b e e t s were adequately blanched by I Q B . Compared t o deep bed steam blanching o r p ipe blanching, IQB gene ra l ly r e s u l t e d i n a s i g n i f i c a n t reduct ion i n e f f l u e n t . S l i g h t drying of the vege tab les before I Q B reduced e f f l u e n t even more; how- ever , product q u a l i t y w a s adversely a f f e c t e d i n most cases . s t r a t e d t h a t t h e I Q B process can s i g n i f i c a n t l y reduce e f f l u e n t volume and BOD genera t ion i n the blanching opera t ion whi le adequately f u l f i l l i n g the objec- t i v e s of blanching. Commercial app l i ca t ion of I Q B appears economically favorable .

I t was demon-

This r epor t was submitted i n f u l f i l l m e n t of P r o j e c t Number S-801484, by Daryl Lund, Univers i ty of Wisconsin, under the p a r t i a l sponsorship of the Environmental P ro tec t ion Agency. Work w a s completed as of August 1973.

ii

CONTENTS

Abstract

List of Tables

Acknowledgments

Sect ions

I

I1

I I1

IV

V

VI

VI1

VI11

IX

X

Conclusions

Recommendat ions

Introduction

Objectives

Materials and Methods

Results and Discussion

Units for Interconversion of Data

References

List of Publications

Append ix--Raw Data

Page

ii

j,V

vi

1

2

3

7

8

18

56

58

60

61

iii

TABLES

No.

1

2

3

4

5

-

6

7

8

9

10

11

12

13

14

15

1 6

17

18

19

20

2 1

Product Forms and P rocess ing Dates

Blanching Methods

Blanching Times and Temperatures

Product Eva lua t ion Tests

Hourly Make-up Water Flow Ra tes and T o t a l S o l i d s Content of P i p e Blancher Water f o r P e a s , Corn, L i m a Beans and Green Beans

Summary of Pea Blanching Data

Summary of O b j e c t i v e Eva lua t ion of Peas

Sumnary o f S u b j e c t i v e E v a l u a t i o n of Peas

Summary of Corn Blanching Data

Summary of O b j e c t i v e Eva lua t ion of Corn

Sumnary of S u b j e c t i v e Eva lua t ion of Corn

Summary of Lima Bean Blanching Data

Summary of O b j e c t i v e Eva lua t ion of Lima Beans

Summary of S u b j e c t i v e E v a l u a t i o n of L ima Beans

Summary of Green Bean Blanching Data

Summary of O b j e c t i v e Eva lua t ion of Green Beans

Sunnnary of S u b j e c t i v e Eva lua t ion of Green Beans

Summary of P o t a t o Blanching Data

Summary of O b j e c t i v e E v a l u a t i o n of P o t a t o e s

Summary of S u b j e c t i v e E v a l u a t i o n of P o t a t o e s

Sumnary of Beet Blanching Data

Page

9

10

15

20

23

27

29

30

31

33

34

36

37

38

41

42

42

44

45

46

i v

TABLES

No.

22

23

-

2 4

25

26

27

2 8

2 9

Summary of Objective Evaluation of Beets

Summary of Subjective Evaluation of Beets

Summary of Carrot Blanching Data

Summary of Objective Evaluation of Carrots

Summary of Subjective Evaluation of Carrots

Estimated IQB Production Units

Factors for Interconversion of Data

Canning Yield Factors

Page

49

5 0

5 1

52

5 2

56

5 7

5 8

V

ACKNOWLEDGMENTS

The cooperation and support of this p r o j e c t by t h e Oconomowoc Canning Company,

Oconomowoc, Wisconsin, i s acknowledged with s i n c e r e thanks. Personnel a t t h e

Sun P r a i r i e and Waunakee P lan t s provided va luab le a s s i s t a n c e .

Pa r t i a l f i n a n c i a l support w a s provided by the Widconsin Canners and Freezers

Association and t h e i r con t r ibu t ion i s g r a t e f u l l y acknowledged.

The IQB blanching u n i t was suppl ied by t h e Western Regional Research Labora-

t o r y , USDA , Berkeley, Ca l i fo rn ia . Obviously, without t h e i r support t h i s

p r o j e c t would n o t have been poss ib l e .

Thanks i s a l s o extended t o the Hughes Company, Columbus, Wisconsin, f o r

supplying some of t he equipment required i n th i s p ro jec t .

A special thanks i s extended t o t h e Water Qua l i ty Laboratory, Wisconsin S t a t e

Department of Natural Resources, Madison. This l abora to ry performed most of

t he water q u a l i t y tes ts and thus provided t h e bulk of t h e r a w d a t a i n t h i s

r e p o r t .

F i n a l l y , acknowledgment i s extended t o personnel i n the Department of Food

Science who contr ibuted t o the success fu l completion of t h i s p r o j e c t . Special

thanks goes t o the personnel of t he Sensory Evaluation Laboratory and t h e

tas te panel members.

v i

SECTION I

CONCLUSIONS

Conventional blanching opera t ions r e s u l t i n the genera t ion of h igh volume,

h igh s t r e n g t h waste streams.

v idua l Quick Blanching, was assessed w i t h the o b j e c t i v e of s i g n i f i c a n t l y re-

ducing blanching e f f l u e n t while main ta in ing product q u a l i t y .

t o peas , corn , l i m a beans, green beans, po ta toes , b e e t s and c a r r o t s p r i o r t o

canning.

The e f f i c a c y of a new blanching system, Indi -

__--- I_-. - -. --- IQB w a s appl ied

--

I Q B was found s u i t a b l e f o r blanching vegetab les p r i o r t o canning. E f f luen t

genera t ion w a s s i g n i f i c a n t l y reduced f o r peas , corn , lima beans and green

beans compared t o p ipe blanching and deep bed steam blanching. Product q u a l i t y

t e s t s ind ica ted tha t IQB blanched, canned products were as good as pipe

blanched, canned products. For pota toes , b e e t s and c a r r o t s , I Q B could be

e f f e c t i v e l y used t o i n a c t i v a t e peroxidase whi le minimizing inequ i ty of heat

t reatment received by the su r face and c e n t e r of the product.

S l i g h t dry ing of the product p r i o r t o IQB f u r t h e r reduced blancher e f f l u e n t s .

However, gene ra l ly canned product q u a l i t y w a s adverse ly a f f e c t e d by t h i s pre-

t reatment .

1

SECTION I1

RE COMME NDA T IONS

This s tudy w a s l imi ted t o a p i l o t p l a n t eva lua t ion of the ind iv idua l quick

blanching (IQB) system. It success fu l ly demonstrated the p o t e n t i a l of reduc-

ing canning p l a n t e f f l u e n t through the use of IQB. Peas, corn , l i m a beans,

green beans, po ta toes , c a r r o t s and bee t s were adequately blanched by IQB and

product q u a l i t y was i n most cases as good as the convent iona l ly blanched-

canned product .

-

--

The next s t e p f o r t h e development of IQB as a commercially v i a b l e blanching

system would be t h e design and i n s t a l l a t i o n of a f u l l s i z e product ion u n i t .

For tha t purpose, information contained i n t h i s r e p o r t and i n o the r published

papers on IQB could be u t i l i z e d f o r providing des ign parameters ( loading ra tes

and res idence times).

I f a p r i v a t e company o r food equipment manufacturing company does not under-

take the development of a commercial IQB u n i t , i t i s recommended t h a t EPA seek

a p a r t i c i p a n t f o r a demonstration grant .

f r eez ing and canning f a c i l i t i e s would undertake t h e p r o j e c t s i n c e the f u l l

p o t e n t i a l of I Q B as a blanching method could then be evaluated.

Preferab ly a company wi th both

2

SECTION 111

INTRODUCTION

GENERAL

Upgrading and maintenance of t h e environment i s a major p r i o r i t y

of government and p r i v a t e s e c t o r a c t i o n . For t h e s o l u t i o n t o the

envi ronmenta l problems, r e s e a r c h and development a c t i v i t i e s a re

d i r e c t e d i n t h r e e major areas: (1) i d e n t i f i c a t i o n of major p o l l u -

t i o n i n p u t from i n d u s t r i a l and o t h e r s o u r c e s , (2) development of

a l t e r n a t i v e p rocesses which e l i m i n a t e o r reduce e f f l u e n t streams,

and (3) development of e f f e c t i v e , economica l ly f e a s i b l e a t i l i z a -

t i o n o r t r ea tmen t of waste material . I n connec t ion w i t h t h e s e

three a c t i v i t i e s , i t was recognized that t h e food p r o c e s s i n g indus-

t r y needed c o n s i d e r a b l e e f f o r t . Although t h e food i n d u s t r y has

advanced t e c h n o l o g i c a l l y i n t h e conve r s ion of r a w a g r i c u l t u r a l

p roduc t s t o consumer-acceptable p r o d u c t s , l i t t l e a t t e n t i o n h a s been

g iven t o u s e of water and g e n e r a t i o n of h i g h s t r e n g t h , l a r g e volume

waste streams.

Waste management w i t h i n food p r o c e s s i n g has s e v e r a l d i s t i n c t i v e

c h a r a c t e r i s t i c s which do n o t a l l o w t h e d i r e c t a d a p t a t i o n of prac-

t i ces used i n o t h e r i n d u s t r i e s . F i r s t , p r o c e s s i n g of f r e s h a g r i -

c u l t u r a l p l a n t material i n t o consumer p roduc t s i s g e n e r a l l y sea-

s o n a l i n n a t u r e r e s u l t i n g i n an uneven demand f o r t r ea tmen t f a c i l i -

t i e s . T h i s h a s c r e a t e d d i f f i c u l t i e s s i n c e i t r e q u i r e s t h a t t h e

food p l a n t e i t h e r have i t s own t r ea tmen t f a c i l i t i e s which a r e used

s p o r a d i c a l l y o r t h a t t h e food p l a n t d i s c h a r g e i t s waste i n t o

3

munic ipa l o r o t h e r t r e a t m e n t f a c i l i t i e s c r e a t i n g unusua l peak

demands. I n e i ther case, waste t r e a t m e n t problems are somewhat

unique .

Second, the composi te waste stream gene ra t ed i n t h e food p r o c e s s i n g

p l a n t i s u s u a l l y a h i g h volume, r e l a t i v e l y low s t r e n g t h stream.

This r e s u l t s from the f a c t tha t water i s r e q u i r e d i n n e a r l y a l l

u n i t o p e r a t i o n s i n food p r o c e s s i n g and u s u a l l y l i t t l e e f f o r t i s

made t o s e g r e g a t e streams based on o r g a n i c s t r e n g t h .

BA C KGROUND

Recent r e s e a r c h a c t i v i t y des igned t o a i d the food p r o c e s s i n g i n -

d u s t r y has c e n t e r e d on i d e n t i f y i n g t h o s e u n i t o p e r a t i o n s where h i g h

s t r e n g t h , h i g h volume waste streams are gene ra t ed and development

of technology r e s u l t i n g i n r e d u c t i o n o f waste g e n e r a t i o n a t t h o s e

u n i t o p e r a t i o n s .

canning i n d u s t r y . I n the conve r s ion of r a w a g r i c u l t u r a l product t o

s h e l f - s t a b l e canned p r o d u c t s , waste streams of s i g n i f i c a n t votlume

and s t r e n g t h are gene ra t ed p e r u n i t o f p roduc t . A n a l y s i s o f the

i n d i v t d u a l u n i t o p e r a t i o n s i n canning i n d i c a t e s tha t t h e u n i t opera-

t i o n b l a n c h i n g (sometimes r e f e r r e d t o as s c a l d i n g ) i s a major s o u r c e

Receiving c o n s i d e r a b l e a t t e n t i o n has been the food

1 of e f f l u e n t . With i d e n t i f i c a t i o n o f a ma jo r p o l l u t i o n a l s o u r c e ,

c o n s i d e r a b l e research e f f o r t has been d i r e c t e d toward development

of e f f e c t i v e , economical ly f e a s i b l e b l a n c h i n g o p e r a t i o n s .

The b l anch ing o p e r a t i o n f u l f i l l s s e v e r a l n e c e s s a r y f u n c t i o n s i n c l u d -

i n g removal o f t i s s u e g a s e s ; i n a c t i v a t i o n o r a c t i v a t i o n o f enzymes,

r e d u c t i o n o f m i c r o b i a l l o a d , c l e a n s i n g of p r o d u c t , w i l t i n g of t i s s u e

t o f a c i l i t a t e packing, and e l e v a t i o n of product t empera tu re going

i n t o the r e t o r t . C u r r e n t l y , the food i n d u s t r y u s e s b o t h h o t water

and steam f o r b l anch ing . Both methods produce l i q u i d wastes h i g h

i n b iochemica l oxygen demand (BOD) and volume, and b o t h r e s u l t i n

l o s s o f water s o l u b l e n u t r i e n t s . Based on d a t a r e p o r t e d by Weckel

4

1 e t a l . f o r two Wisconsin canning p l a n t s , a 90% r e d u c t i o n i n b l a n c h e r

e f f l u e n t would r educe t o t a l p l a n t waste f low by 10 t o 20% and , more

s i g n i f i c a n t l y , reduce t o t a l p l a n t BOD by 20 t o 50%. The Na t iona l

Canners A s s o c i a t i o n e s t i m a t e d t h a t i f a new b lanch ing method which

reduced waste wa te r s t r e n g t h by 50% w e r e used f o r t h e seven vege-

t a b l e s processed i n t h e l a r g e s t tonnage , a t o t a l of approximate ly 32

m i l l i o n kg. (70 m i l l i o n pounds) of BOD and 18 m i l l i o n kg. ( 4 0 m i l l i o n

pounds) of suspended s o l i d s would be e l i m i n a t e d from t rea tmen t p l a n t

l oad ings .

2

I n t h e abatement of waste water f low and l o s s of s o l i d s from product

i n canning and f r e e z i n g p l a n t s , a s t u d y w a s i n i t i a t e d i n 1970 t o

d e s i g n a b l anch ing p rocess which would have a waste water f low of

o n l y 10% of a commercial h o t water b l anche r . The p r o j e c t w a s sup-

po r t ed by t h e U n i v e r s i t y of Wisconsin and t h e USDA, and w a s conducted

by M. E. Lazar and D. B. Lund a t t h e Western Market ing and N u t r i t i o n

Research D i v i s i o n , USDA. The p r o j e c t r e s u l t e d i n a new concept of

h e a t i n g foods and t h e a p p l i c a t i o n t o b l anch ing w a s demonstrated . The p r o c e s s , i n d i v i d u a l qu ick b l anch ( I Q B ) , r e q u i r e d f u r t h e r eva lua -

t i o n and , t h e r e f o r e , t h e Western Labora tory conducted a s t u d y u t i -

l i z i n g IQB p r i o r t o f r e e z i n g w h i l e t h e e v a l u a t i o n of I Q B f o r b lanch-

i n g p r i o r t o canning w a s conducted i n a Wisconsin canning p l a n t .

3 , 4

The I Q B p rocess i s a two-stage u n i t o p e r a t i o n . In t h e f i r s t s t a g e ,

t h e food p i e c e i s exposed t o a h e a t sou rce (condensing s team) f o r

such d u r a t i o n t h a t t h e mass-average tempera ture i s i n t h e range re-

q u i r e d f o r b l anch ing ( g e n e r a l l y g r e a t e r t han 85 C [185 F ] ) . The

p i e c e is then t r a n s f e r r e d t o a second s t a g e where t h e p i e c e i s he ld

a d i a b a t i c a l l y u n t i l t h e thermal g r a d i e n t s have e q u i l i b r a t e d t o t h e

mass average t empera tu re and t h e o b j e c t i v e s of b l anch ing have been

accomplished. The p rocess r e s u l t s i n less waste g e n e r a t i o n because :

1) steam condensa t ion i s l i m i t e d t o t h a t r e q u i r e d f o r h e a t i n g t h e

5

product i n t o t h e b l anch ing t empera tu re r ange , 2 ) t h e r e i s minimal

o p p o r t u n i t y f o r t i s s u e damage and subsequent l o s s of c e l l u l a r j u i c e s ,

and 3 ) t h e r e i s no o v e r h e a t i n g of some of t h e t i s s u e as i n deep bed

steam b lanch ing which can r e s u l t i n t i s s u e damage.

5 Lund r e p o r t e d on

canning. I n t h a t

blanched , canned ,

the a p p l i c a t i o n of I Q B t o v e g e t a b l e s p r i o r t o

s t u d y , peas , c o r n , lima beans and green beans were

s t o r e d and o b j e c t i v e l y and s u b j e c t i v e l y eva lua ted .

Eva lua t ion of IQB, IQB w i t h p red ry ing and conven t iona l p i p e b l anch ing

showed that up t o a 9 9 1 r e d u c t i o n i n waste water g e n e r a t i o n could be

achieved w i t h IQB. The s t u d y a l s o r e v e a l e d t h a t a l though p red ry ing

t o g r e a t e r t h a n a 6% weight r e d u c t i o n would f u r t h e r reduce waste

water g e n e r a t i o n , product q u a l i t y w a s a d v e r s e l y a f f e c t e d .

6

SECTION I V

OBJECTIVES

The r e s u l t s i n t h i s r e p o r t are a c o n t i n u a t i o n and e x t e n s i o n of t h e 1971

s tudy . The p r e s e n t s t u d y was unde r t aken f o r s e v e r a l r e a s o n s : 1) t o con-

f i r m t h e 1971 r e s u l t s w i t h IQB, 2) t o compare t h e IQB p rocess t o deep-bed

steam b l a n c h i n g , 3) t o app ly t h e IQB p rocess t o d i f f e r e n t v a r i e t i e s of

peas, 4 ) t o extend t h e IQB p rocess t o t h e b l anch ing of r o o t c r o p s such a s

p o t a t o e s , c a r r o t s and b e e t s , and 5) t o e v a l u a t e t h e hea t -on ly s t a g e of

t h e IQB p rocess as a b lanch ing method. O b j e c t i v e 5) w a s inc luded i n t h e

s t u d y s i n c e i t had been observed t h a t a f t e r b l anch ing , and p r i o r t o can

f i l l i n g , v e g e t a b l e s are o f t e n he ld f o r one t o two minutes d u r i n g which

t h e r m a l e q u i l i b r a t i o n could be accomplished.

h e l d i n a r e l a t i v e l y l a r g e mass t o reduce thermal l o s s e s , b l anch ing could

be accomplished. The v e g e t a b l e s used i n t h i s s tudy i n c l u d e peas (smooth

and wr ink led - sk in va r i e t i e s ) , c o r n , l i m a beans , g reen beans , p o t a t o e s ,

c a r r o t s and b e e t s .

I f t h e v e g e t a b l e s could be

7

SECT ION ' v

MATERIALS AND METHODS

PRODUCTS AND PROCESSING TIMETABLE

Products chosen f o r t h i s s t u d y were t h o s e grown and /o r processed i n

l a r g e q u a n t i t y i n Wisconsin. The 1971 s t u d y w a s done on A l s w e e t

p e a s , Midway c o r n , S l im Green g reen beans and l i m a beans ( v a r i e t y

unknown), and consequen t ly , t o v e r i f y t h e 1971 s t u d y , t h e s e p roduc t s

w e r e used i n t h i s s tudy . S i n c e t h e r e w a s concern r e g a r d i n g t h e

r e sponse of the smooth-skin pea v a r i e t y t o t h e I Q B p r o c e s s , Alaskan

peas were a l s o used. Two wr inkled-sk in v a r i e t i e s , Alsweet and Per-

f e c t i o n , were used. I n a d d i t i o n t o t h e s e f o u r v e g e t a b l e s , t h e r o o t

c r o p s , p o t a t o e s , c a r r o t s and b e e t s , were a l s o processed .

The e f f e c t of h a r v e s t d a t e on the c h a r a c t e r i s t i c s of b l a n c h e r e f -

f l u e n t w a s a s s e s s e d by making b l anch ing r u n s throughout the p rocess -

i n g season . Experiments were conducted on t h r e e days f o r peas and

c o r n , two days f o r lima beans and green beans and one day f o r po ta-

t o e s , c a r r o t s and b e e t s . Product forms and p rocess ing d a t e s are

g iven i n Table 1.

A l l p roduc t s used i n t h i s s t u d y were ob ta ined from e i t h e r t h e Sun

P r a i r i e , Merr i l l , o r Waunakee p l a n t s of t h e Oconomowoc Canning

Company, Oconomowoc, Wisconsin. Peas were t aken from t h e produc-

t i o n l i n e immediately a f t e r i n s p e c t i o n and j u s t p r i o r t o b lanching .

They were t r a n s p o r t e d t o the p i l o t p l a n t a t t h e Department of Food

Sc ience , Babcock H a l l , U n i v e r s i t y of Wisconsin-Madison under water c.

8

t o minimize p roduc t d e t e r i o r a t i o n . The b l a n c h i n g r u n w a s s t a r t e d

w i t h i n two hour s o f l e a v i n g t h e cann ing p l a n t .

Tab le 1. PRODUCT FORMS AND PROCESSING DATES

Process ing d a t e

6 I22 172

6 /26 /72

7/26/72

8/16/72

813 1/72

9/11/72

101 3/72

l O / l 1 / 72

101 9/72

10/10/72

10/31/72

111 2/72

111 7/72

P roduc t

Peas

Peas

Peas

Corn

Corn

Corn

Lima b an I

Lima bean

Green bean

Green bean

Po t a t o e s

Beets

C a r r o t s

Variety

Alsweet

Alaskan

P e r f e c t i o n

Midway

Midway

Midway

Thorogreen

Thorogreen

S l im g reen

Slim g r e e n

S u p e r i o r

Ruby queen

Nantes

Form

4 s i e v e

3 sieve

3, 4 , 5 s i e v e (mixed)

Whole k e r n e l

Whole ke rne 1

Whole k e r n e l

3 sieve

3 s i e v e

3.8 cm.

3.8 cm.

0.64 cm. (114 i n . ) s l i c e ; medium

0.64 cm. (114 i n . ) s l i ce ; medium

0.64 cm. s l i c e ; medium

Corn w a s t aken o u t o f the p r o c e s s i n g l i n e immediately b e f o r e the

c o n v e n t i o n a l b l a n c h i n g s t e p . The co rn had been washed and sc reened .

It w a s a l s o t r a n s p o r t e d t o the p i l o t p l a n t under water.

Cut g reen beans were r e c e i v e d from the Merrill, Wisconsin p l a n t and

were t r a n s p o r t e d from the p l a n t t o Madison by t r u c k . The g reen

beans were blanched and f u r t h e r processed immediately a f t e r r e c e i v -

i n g them.

Lima beans were t aken from the p r o c e s s i n g l i n e immediately a f t e r

i n s p e c t i o n and were t r a n s p o r t e d t o t h e p i l o t p l a n t under water.

9

P o t a t o e s , c a r r o t s and b e e t s were ob ta ined from t h e Waunakee p l a n t .

A l l r o o t c r o p p roduc t s had been steamed and /o r l y e - t r e a t e d , p e e l e d ,

g raded , and s l i c e d . Medium s l i c e (3 .2 - 4 .4 cm. d i a m e t e r ) w a s used

i n t h e b l anch ing s t u d i e s . T e s t s i n d i c a t e d t h a t t h e r e w a s enzymic

a c t i v i t y (peroxidase) even though t h e product had r ece ived a thermal

t r ea tmen t . The product w a s b rought t o t h e l a b o r a t o r y and processed

irmned i a t e ly . BLANCHING METHODS AND EQUIPMENT

F ive b l anch ing methods were i n v e s t i g a t e d i n t h i s s t u d y and are shown

i n Table 2 . The f i r s t method w a s IQB ( i n d i v i d u a l qu ick b l anch) .

Tab le 2. BLANCHING METHODS

Method

IQB IQB w i t h

p red ry ing

I Q B h e a t o n l y

Deep bed steam

P ipe

Peas

X

X

X

X

X

Corn

X

X

X

X

X

Lima beans

X

X

X

X

X

Green beans

X

X

X

Pota- t o e s

X

X

X

C a r r o t s Beets t

The equipment w a s t h e same as that d e s c r i b e d i n an earlier pub l i ca -

t i o n 3 and w a s on loan from t h e Western Regional Research Labora tory .

I n e s sence t h e equipment c o n s i s t e d of two

s e p a r a t e b e l t u n i t s , the f i r s t o f which w a s approximate ly 91.4 cm.

(3 f t . ) by 21.6 cm. (8.5 in . ) and the second of which w a s approxi -

ma te ly 122 cm. (4 f t . ) by 20.3 cm. (8 in . ) . The f i r s t u n i t was t h e

h e a t i n g s e c t i o n and had a feed hopper through which a s i n g l e l a y e r

o f product could b e d i scha rged o n t o the moving b e l t . The r e s i d e n c e

10

t i m e i n t h i s u n i t could be varied from 20 sec. t o 2 . 5 min. The

second u n i t , t h e hold u n i t , had a d j u s t a b l e b e l t speed and tunnel

length. Tunnel length w a s adjusted by changing t h e length of t h e

cover on t h e u n i t . I n a l l experimental runs reported h e r e , t h e

e f f e c t i v e b e l t length w a s 30.5 cm. (1 f t . ) . A diagram of t h e I Q B

u n i t i s shown i n Figure 1.

Figure 1. I Q B BLANCHING UNIT

/ M O N O L A Y E R I . A--CURTAIN -. I

Fast Belt (Live Steam Heat) HOLDING COOL ING SECT ION

SECTION (Opt ionol) Slow Belt (Chilled Air)

(Insulated, Ad ia bat i d

The h e a t u n i t w a s heated by l i v e steam which w a s d i s t r i b u t e d by two

pipe d i s t r i b u t o r s , one below and one above t h e b e l t . The d i s t r i b u t o r

below t h e b e l t d i r e c t e d t h e steam p a r a l l e l t o t h e b e l t s o product

would not be blown o f f t h e b e l t , and t h e d i s t r i b u t o r above t h e b e l t

w a s d i r e c t e d toward t h e cover on t h e u n i t . The hold s e c t i o n w a s

heated i n d i r e c t l y by steam i n two copper c o i l s , one on each w a l l

of t h e u n i t . The steam condensate and excess steam from t h i s s e c t i o n

w a s used t o preheat t h e b e l t going i n t o t h e hold s e c t i o n . The hold

s e c t i o n w a s separated from t h e h e a t u n i t by a s h o r t t r a n s f e r zone

wi th a canvas c u r t a i n .

u n i t i n t o t h e hold u n i t .

Some steam leakage d id occur from t h e h e a t

11

The I Q B u n i t w a s equipped w i t h e f f l u e n t d r a i n s on b o t h t h e h e a t and

ho ld u n i t s .

recorded s e p a r a t e l y , a n a l y s i s and r e p o r t i n g of the d a t a w e r e done

on t h e t o t a l .

Al though t h e volume o f e f f l u e n t from each u n i t w a s

The second b lanch ing method was I Q B w i t h p red ry ing .

t h e v e g e t a b l e s were cyc led through a 183 cm. (6 f t . ) long by 30.5 cm.

(1 f t . ) wide v i b r a t i n g bed d r y e r .

bu lb ) w a s passed up through t h e v e g e t a b l e bed, and t h e v e g e t a b l e s

were p r e d r i e d t o approx ima te ly a 6% weight r e d u c t i o n .

r e d u c t i o n w a s e s t a b l i s h e d based on r e s u l t s i n t h e 1971 s tudy . It

w a s found t h a t a t h i g h e r weight r e d u c t i o n i r r e v e r s i b l e d e h y d r a t i o n

occur red ( i . e . the product would n o t r e h y d r a t e t o i n i t i a l w e t weight )

and product q u a l i t y w a s a d v e r s e l y a f f e c t e d (most n o t a b l y through

e x c e s s i v e s k i n r u p t u r e o r e x c e s s i v e browning).

For p r e d r y i n g ,

A i r a t 71-82 C (160-180 F) ( d r y

A 6% weight

The t h i r d b l anch ing method (IQB h e a t o n l y ) u t i l i z e d on ly t h e h e a t

b e l t of t h e IQB u n i t . Immediately a f t e r go ing through t h e h e a t i n g

u n i t t h e product was d i scha rged i n t o p l a s t i c bucke t s . Product w a s

h e l d i n t h e bucke t s u n t i l canning.

The f o u r t h method w a s deep bed steam blanching . The h e a t s e c t i o n of

t h e IQB u n i t w a s used f o r t h i s method a l s o . The p roduc t w a s d i s -

charged on to t h e b e l t i n a 6.4-7.6 cm. (2.5-3 i n . ) deep l a y e r .

Residence time i n t h e u n i t w a s 2.5 min. f o r a l l deep bed b l anch ing

t r ia l s .

The f i f t h b l anch ing method e v a l u a t e d w a s t h e commercial method--

p i p e b l anch ing . The u n i t c o n s i s t e d of 122-152 m. (400-500 f t . ) of

11.4 cm. (4.5 in . ) d i ame te r s t a i n l e s s steel p ipe . The l e n g t h w a s

v a r i a b l e so t h a t t h e r e s i d e n c e time could be a d j u s t e d . Product w a s

metered i n t o t h e p i p e a t a p r e s e t rate so t h a t t h e water t o product

r a t i o w a s c o n s t a n t . A f t e r b l anch ing , t h e product w a s dewatered a t

12

a dewa te r ing reel and was f u r t h e r processed . The b lanch water w a s

t h e n sc reened , make-up water w a s added and t h e water r e c y c l e d i n t o

t h e p ipe . Water and v e g e t a b l e s i n t h e p i p e b l a n c h e r were h e a t e d

by d i r e c t steam i n j e c t i o n .

Blanching t imes used i n t h e IQB h e a t / h o l d s e c t i o n s were determined

by making s imple o b s e r v a t i o n s on t h e p i p e b l anch ing o p e r a t i o n .

peas , i t w a s observed t h a t conven t iona l p i p e b l anch ing o p e r a t i o n

r e s u l t e d i n pe rox idase i n a c t i v a t i o n and, t h e r e f o r e , pe rox idase i n -

a c t i v a t i o n w a s t h e c r i t e r i o n f o r e s t a b l i s h i n g h e a t / h o l d times i n

IQB.

d e s c r i b e d i n Lund et a. t u r e i n p i p e b l anch ing w a s approximate ly 77 C (170 F) and, conse-

q u e n t l y , h e a t / h o l d times were chosen t h a t would r e s u l t i n a f i n a l

co rn o r lima bean t empera tu re of 77 C. Green beans w e r e a l s o p i p e

blanched a t 77 C b u t t h e conven t iona l IQB p rocess could n o t be used.

With g reen beans , t h e f u n c t i o n of b l anch ing i s t o act ivate t h e enzyme

p e c t i n methyl esterase which p reven t s s lough ing of t h e g reen bean

f o l l o w i n g canning. S ince t h e enzyme i s i n a c t i v a t e d a t t empera tu res

above 82 C (180 F ) , t h e IQB h e a t s e c t i o n could n o t be h e a t e d w i t h

100 C (212 F) steam. There fo re , a steam-air m i x t u r e a t 79 C (175 F)

w a s used i n t h e I Q B h e a t i n g s e c t i o n .

t h a t would r e s u l t i n a n e q u i l i b r a t e d t empera tu re of 77 C. For pota-

t o e s , c a r r o t s and b e e t s , a d i r e c t comparison t o p i p e b l anch ing could

n o t b e made s i n c e t h e s e p roduc t s are n o t u s u a l l y blanched p r i o r t o

canning.

r e t o r t i n g i s i n t h e p e e l i n g o p e r a t i o n . These p roduc t s were inc luded

i n t h e IQB and deep-bed expe r imen t s , however, s i n c e they are blanched

p r i o r t o f r e e z i n g and some p r o c e s s o r s have exper ienced u n d e s i r a b l e

c o l o r changes ( p a r t i c u l a r l y w i t h b e e t s and p o t a t o e s ) which can be

avoided by b l anch ing a f t e r s l i c i n g o r d i c i n g .

were chosen such t h a t pe rox idase w a s i n a c t i v a t e d . For deep-bed

b l anch ing , a l l v e g e t a b l e s were blanched f o r 2.5 minu tes , t h e maximum

For

Appropr i a t e h e a t / h o l d t imes were de termined by t h e procedure

For c o r n and l ima beans , water tempera- 4

Heat /hold times were chosen

The o n l y h e a t t r e a t m e n t t h e s e p roduc t s receive p r i o r t o

Blanching c o n d i t i o n s

13

r e s i d e n c e t i m e of t h e I Q B h e a t s e c t i o n . Blanching c o n d i t i o n s f o r

a l l v e g e t a b l e s are shown i n Table 3.

Table 3. BLANCHING TIMES AND TEMPERATURESa

Commodity

Peas

Corn

L ima b earis

Green beans

Po ta toes

C a r r o t s

Beets

IQB

30 sec /100 C h e a t

45 s e c hold

20 sec /100 C h e a t

30 s e c hold

20 sec /100 C h e a t

80 sec hold

20 sec /82 C h e a t

80 s e c hold

60 sec/100 C h e a t

60 sec hold

45 sec /100 C h e a t

60 s e c hold

45 sec/100 C h e a t

60 s e c hold

Heat on ly

30 sec /100 C

D e e D bed

2.5 min/100 C

2.5 min/100 C

2.5 m i d 1 0 0 C

2.5 min/82 C

2.5 min/100 C

2.5 min/100 C

2.5 min/100 C

P ipe

4 m i d 9 3 c

1.5 min/77C

4 min/77 c

2 m i d 7 7 C

a A l l t ime / t empera tu re combina t ions r e s u l t e d i n n e g a t i v e pe rox idase excep t f o r green beans. Time/Temperature (C).

For each expe r imen ta l r u n , t h r e e 9.09 kg. (20 l b . ) ba t ches of t h e

v e g e t a b l e were t r e a t e d by one of t h e f o u r steam b lanch ing methods.

I n i t i a l we igh t , weight a f t e r d r y i n g ( i f t h e product was p r e d r i e d ) ,

and weight a f t e r b l anch ing were recorded . For each 9.09 kg. r u n , a l l

waste water gene ra t ed by p r o c e s s i n g t h e v e g e t a b l e i n t h e b l a n c h e r was

measured. A composite sample of t h e waste water was s u b j e c t e d t o

a n a l y s i s f o r t h e fo l lowing : 1) BOD5, 2 ) COD, 3) t o t a l s o l i d s , 4) suspended s o l i d s , 5 ) s o l u b l e phosphorus, 6 ) t o t a l phosphorus, 7)

t o t a l o rgan ic n i t r o g e n , 8) NH3-Nitrogen, 9) NO3-Nitrogen, 10) NO2-

N i t rogen , 11) v o l a t i l e s o l i d s , 12) suspended v o l a t i l e s o l i d s , and

14

13) pH. P a r t of t h e a n a l y s e s were performed by t h e Wisconsin Depart-

ment of Na tu ra l Resources. I n a l l c a s e s t h e s t anda rd methods f o r

a n a l y s e s were used . 6

In o r d e r t o r e p o r t waste water g e n e r a t i o n on t h e b a s i s of amount of

product p rocessed , a b l ank was determined f o r each run by o p e r a t i n g

t h e equipment w i t h t h e steam on and t h e b e l t s moving f o r a pe r iod

of time e q u a l t o t h e time t o p rocess t h e 9.09 kg. l o t . Equipment

e f f l u e n t (due t o h e a t l o s s e s from t h e equipment, h e a t i n g t h e b e l t and

any water c a r r i e d i n t h e steam l i n e ) was measured and t h i s v a l u e sub-

t r a c t e d from t h e volume gene ra t ed d u r i n g t h e a c t u a l run. A l l a n a l y s i s

v a l u e s were c o r r e c t e d by t h e r e s u l t i n g d i l u t i o n f a c t o r .

f o l l o w i n g b l a n c h i n g , samples were f i l l e d i n t o 303 x 406 cans t o t h e

Immediately

a p p r o p r i a t e f i l l we igh t , b r i n e added, cans s e a l e d and r e t o r t e d i n a

S t e r i t o r t fo l lowing t h e h e a t / c o o l p rocess used i n t h e canning p l a n t .

For t h e p ipe b l a n c h e r , e f f l u e n t was c o l l e c t e d a t t h e dewa te r ing ree l

and s u b j e c t e d t o t h e same a n a l y s e s as o t h e r samples. Water usage w a s

monitored by a water meter i n t h e water make-up l i n e and was recorded

d a i l y . By knowing t h e d a i l y case pack on t h e l i n e , t h e l i t e r s of

water p e r case of product could be c a l c u l a t e d . S i n c e t h e p i p e

b l anch ing water was hea ted by d i r e c t steam i n j e c t i o n , t h e e f f l u e n t

gene ra t ed by t h e system w a s l a r g e r t h a n t h a t c a l c u l a t e d from t h e

water make-up r e a d i n g s . To a d j u s t f o r t h e steam condensa t ion i n

h e a t i n g t h e product up, i t was assumed t h a t 4.23 kg. (9.3 l b . ) of

steam would condense f o r eve ry 45.5 kg. (100 l b . ) of product be ing

hea ted 38.0 C (100 F) . This r e s u l t e d i n 91.7 l i t e r s of steam con-

d e n s a t i o n p e r kkg. of product (22 g a l / t o n ) . This v a l u e has been

added t o a l l p i p e b l a n c h e r v a l u e s as c a l c u l a t e d from water meter

r e a d i n g s . Waste g e n e r a t i o n r e p o r t e d f o r t h e p i p e b l anch ing sys tem

w i l l s t i l l be low s i n c e t h i s does n o t accoun t f o r h e a t l o s s e s from

t h e p i p i n g system. However, f o r t h e system w e monitored h e a t l o s s e s

would probably n o t c o n t r i b u t e more than 8.3-20.9 l . /kkg. (2-5 g a l / t o n )

of product processed . 15

To i n s u r e t h a t r e p r e s e n t a t i v e samples of waste water were be ing

c o l l e c t e d from t h e p i p e b l a n c h e r , on some occas ions (at least two

days f o r each v e g e t a b l e ) , water samples w e r e c o l l e c t e d a t two-hour

i n t e r v a l s . R e s u l t s i n d i c a t e d that w i t h i n two hour s of s t a r t - u p t h e

b l a n c h e r water w a s i n s t e a d y state. T h e r e f o r e , a l l samples were

t aken a t least two hour s afker s t a r t - u p . For l a te r e v a l u a t i o n and

comparison, several cases of canned v e g e t a b l e s processed a t t h e same

time t h e expe r imen ta l samples were processed were brought t o t h e

l a b o r a t o r y .

PRODUCT EVALUATION

A f t e r b l anch ing , t h e product w a s hand packed i n t o 303 x 406 c a n s ,

b o i l i n g water and t h e a p p r o p r i a t e volume of c o n c e n t r a t e d b r i n e were

added and t h e cans were s e a l e d . The cans w e r e t h e n t h e r m a l l y proc-

e s sed i n a S t e r i t o r t u s i n g r o t a t i o n speed and h e a t / c o o l t i m e s iden-

t i c a l t o t h o s e used i n t h e canning p l a n t . Product w a s t h e n s t o r e d

a t 32 C (90 F) a l o n g w i t h c o n v e n t i o n a l l y processed product which had

been o b t a i n e d from t h e canning p l a n t . Product e v a l u a t i o n s were con-

duc ted a t 1, 3 , 6 and 9 months' s t o r a g e . The tes ts performed on

each p roduc t are shown i n Table 4 . Standard procedures were followed

f o r a l l tes ts . The method of Van Buren e t a l .7 was used f o r t h e

s lough tes t on green beans. A t each e v a l u a t i o n a f i v e - c a n subsample

f o r each expe r imen ta l p rocess and conven t iona l p rocess w a s ana lyzed .

Product q u a l i t y w a s a s s e s s e d by t r i a n g l e tas te t e s t comparing each

e x p e r i m e n t a l l y processed p roduc t t o t h e co r re spond ing c o n t r o l p rocess

product (canned product ob ta ined from t h e canning p l a n t ) . T a s t e

t e s t i n g w a s conducted i n t h e Sensory Eva lua t ion Labora to ry of t h e

Department of Food Sc ience u s i n g pe r sonne l who were t r a i n e d i n

senso ry e v a l u a t i o n . D i f f e r e n c e s could be a s s e s s e d on t h e b a s i s of

c o l o r , t e x t u r e o r f l a v o r and p r e f e r e n c e w a s no ted . To s t r e a m l i n e

t h e p r e s e n t a t i o n of senso ry e v a l u a t i o n d a t a , two p i e c e s of informa-

t i o n were gene ra t ed . The f i r s t c o n s i s t s of t h r e e numbers s e p a r a t e d

1 6

Table 4 . PRODUCT EVALUATION TESTS

T e s t

Taste pane l

Can vacuum

Drained weight

B r i n e sediment

Slough

P e r c e n t s p l i t s

Peas

X

X

X

X

X

Corn

X

X

X

Lima beans

X

X

X

Green beans

X

X

X

X

X

Pota- t o e s

X

X

X

C a r r o t s Beets +- by s l a s h e s such as 10/5/5. The f i r s t number (10) is t h e number of

c o r r e c t judgments which p r e f e r r e d t h e e x p e r i m e n t a l l y blanched canned

p roduc t ; t h e second number (5) i s t h e number of c o r r e c t judgments

which p r e f e r r e d t h e c o n t r o l sample; and t h e las t number (5) i s t h e

number of c o r r e c t judgments which showed no p r e f e r e n c e .

p i e c e of i n fo rma t ion w a s t h e level of d i s t i n c t i o n between samples.

There w a s e i t h e r no s i g n i f i c a n t d i f f e r e n c e (NS) o r d i f f e r e n c e s

were i d e n t i f i a b l e a t t h e 0.1%, 1% o r 5% level.

The second

17

SECTION V I

RESULTS AND DISCUSS I O N

FLOW V A R I A B I L I T Y OF BLANCHING WASTES

During t h e p r o c e s s i n g season d a i l y water meter r e a d i n g s were recorded

f o r water usage i n t h e p i p e b l a n c h e r f o r peas, c o r n , and green beans .

Examination of t h e d a t a showed t h a t t h e most c o n s i s t e n t c h a r a c t e r i s t i c

w a s t h e extreme v a r i a b i l i t y i n water used p e r c a s e o r t o n of v e g e t a b l e .

The d a t a were s o scattered t h a t i t i s tenuous a t b e s t t o draw con-

c l u s i o n s . However , i n t h e hope of comparing IQB t o p i p e b l anch ing , ave rage water usage rates w e r e c a l c u l a t e d . An example of v a r i a b i l i t y

of d a t a i s t h e r ange of d a t a r e p o r t e d f o r green bean b l anch ing . On

8/24/72 t h e r e w a s a r e p o r t e d 24.2 l . / c a s e (6.4 g a l / c a s e ) wa te r usage

i n t h e p i p e b l a n c h e r ; whereas on 9/16/72 on ly 0.45 l . / c a s e (0.12 g a l /

c a s e ) w a s recorded . Th i s i s over a 50- fo ld d i f f e r e n c e ! I n pea

b l a n c h i n g , on 6 /27/72 , 6.6 l ./case (1.75 g a l / c a s e ) w a s recorded f o r

t h e p i p e b l anche r compared t o 0 . 3 3 l . / c a s e (0.088 g a l / c a s e ) on

7 /19/72 , a 20- fo ld d i f f e r e n c e . This tremendous v a r i a b i l i t y con-

t r i b u t e s t o many m i s i n t e r p r e t a t i o n s r e g a r d i n g water usage i n b lanch-

i n g o p e r a t i o n s . One f a c t o r r e s p o n s i b l e f o r v a r i a b i l i t y i s incomple te

knowledge of t h e b l anch ing system. In o u r c a s e w e were n o t informed

t h a t t h e b l a n c h e r could be f i l l e d from two s e p a r a t e s o u r c e s , one a t

t h e i n l e t end and one a t t h e d i s c h a r g e end. Consequently, w e on ly

monitored water i n l e t from one source . Once t h i s w a s recognized w e

were a b l e t o s c r e e n t h e d a t a t o a s s u r e t h a t a r e p r e s e n t a t i v e v a l u e

w a s r e p o r t e d . A second f a c t o r r e s p o n s i b l e f o r v a r i a b i l i t y of f low i s

t h e l a c k of c o n t r o l on t h e b l anch ing u n i t o p e r a t i o n . Many t i m e s t h e

/

18

b lanche r i s n o t equipped w i t h a f low r e g u l a t i n g d e v i c e b u t r a t h e r

t h e r e i s j u s t a water l i n e b r i n g i n g water i n t o t h e system. The

foreman o r worker mere ly opens a water valve t o the b l a n c h e r and h a s

no guidance as t o the a p p r o p r i a t e f low ra te t o use . T h e r e f o r e , on

some occas ions f low i s ve ry h i g h , w h i l e on o t h e r s it i s v e r y low.

I n a d d i t i o n t o t h e v a r i a b i l i t y of f low between days , t h e r e i s a l s o

v a r i a b i l i t y of f low w i t h i n a day, An example of water f low from

blanching d u r i n g one day o f p rocess ing f o r p e a s , c o r n , g reen beans

and lima beans i s shown i n Table 5. The p e r c e n t t o t a l s o l i d s of t h e

b l a n c h e r e f f l u e n t i s a l s o g iven . It can b e seen t h a t t h e r e i s con-

s i d e r a b l e v a r i a b i l i t y i n the water usage p a t t e r n throughout the

p rocess ing day. T h i s v a r i a b i l i t y r e f l e c t s the c y c l i c n a t u r e of t h e

b l anch ing o p e r a t i o n i n t h a t t h e b l a n c h e r i s g e n e r a l l y d r a i n e d and

r e f i l l e d several times d u r i n g t h e o p e r a t i n g day. This c l eanup is

n e c e s s i t a t e d by t h e fac t t h a t t h e s o l i d s leached from t h e t i s s u e

d u r i n g b l anch ing undergo o x i d a t i v e and thermal d e g r a d a t i o n t o v e r y

f l a v o r f u l compounds. These compounds can produce o f f - f l a v o r i n t h e

f i n a l p roduct u n l e s s t hey are removed p e r i o d i c a l l y . For peas t h e

b l a n c h e r was r e f i l l e d eve ry 6-8 h o u r s , f o r co rn e v e r y 12 h o u r s , and

f o r lima beans eve ry s i x hours . For g reen beans t h e b l anche r w a s

r e f i l l e d eve ry s i x hour s b u t no make-up water w a s added between re-

f i l l s . Under t h e s e c o n d i t i o n s t h e t o t a l s o l i d s i n t h e b l anch water

v a r i e s c o n s i d e r a b l y , f o r example, from 0.55% TS t o 1.35% TS. With

t h e o t h e r v e g e t a b l e s t h e % TS i s k e p t r e l a t i v e l y c o n s t a n t by t h e

a d d i t i o n of make-up water.

The d a t a r e p o r t e d i n Table 5 f o r l i m a beans are from t h e 1971 s tudy .

No d a t a are a v a i l a b l e on water usage f o r lima beans f o r 1972 due t o

a change i n b l anch ing c o n d i t i o n s . I n 1971, t h e water make-up ra te

was approximate ly 76 l . /case (20 g a l / c a s e ) , about t e n t imes h i g h e r

t han that r e p o r t e d f o r t h e o t h e r v e g e t a b l e s . A t t h e end of t h e 1971

19

Table 5. HOURLY MAKE-UP F'LOW RATES AND TOTAL SOLIDS CONTENT OF PIPE BLANCHER WATER FOR PEAS, CORN, LIMA BEANS AND GREEN BEANS

Time (hrs)

2

2.5 3

3.5

4 6

8

10 12

14 16

18

Peas % TS 1 . h

2.31 719 2.15 590

2.24 795 2.90 636

2.90 689 2.70 708

- Corn % TS 1. /hr

2.47 1703

2.58 1363 2.50 1363 2.30 1363

2.05 1817

1.09 1249

2.24 1400 3.00 1400 2.79 4126 2.12 265 2.26 2 725

1.95 1779

Lima beans

Yo TS 1. /hr

0.59 24600

0.39 20250

0.62 30470

0.43 15030 0.37 20530

Green beans

% TS l./hr

0.71 8880

1.12 0

0.63 6230 1.01 0

0.97 0

0.55 9750 1.23 0

1.35 0

processing season this observation was made to the plant personnel

who immediately sought to correct the situation for 1972. The high water usage rate was the result of the foaming problem associated with lima bean blanch water. In 1972, several corrective actions were taken: 1) use of an antifoam agent in the blanch water, 2) use of hard water instead of soft and 3) maintenance of a full reservoir prior to the pump (eliminated air entrapment). Since the water make-up line was hard water and fed several pieces of equipment si-

multaneously, it was impossible to monitor water addition rates. How- ever, after conversations with plant personnel, it was estimated that water usage rates for lima beans were about the same as those for

corn.

20

I

CONDENSATION OF RAW DATA

I n t h i s t ype of s t u d y volumes of r a w d a t a can be ob ta ined and much

of i t can , i n t u r n , be m u l t i p l i e d c o n s i d e r a b l y by c a l c u l a t i o n s . I n

o r d e r t o s i m p l i f y t h e examination of d a t a and t o r each t h e r e a l l y

p e r t i n e n t i n fo rma t ion ob ta ined i n t h i s s t u d y , t h e r a w d a t a were con-

densed and o n l y t h e p e r t i n e n t c a l c u l a t i o n s were performed. Many

more c a l c u l a t i o n s can be done b u t t h e y do n o t serve t o demonst ra te

more e f f e c t i v e l y t h e r e s u l t s con ta ined h e r e i n .

The r a w d a t a f o r each of t h e b l anch ing runs are g iven i n t h e Appendix

i n Tables A 1 - A 1 4 . The f i r s t t a b l e f o r each product p r e s e n t s t h e

p h y s i c a l c h a r a c t e r i s t i c s of t h e run such as b e l t l o a d i n g s , e f f l u e n t

gene ra t ed (expressed as l . / c a s e ) , p roduct y i e l d and s o l i d s los t as

product . " B e l t loading ' ' r e s u l t s w i l l be d i s c u s s e d i n a l a t e r sec -

t i o n . " E f f l u e n t gene ra t ed" w a s c a l c u l a t e d from t h e volume of waste

c o l l e c t e d p e r u n i t of r a w product . "Product y i e l d " i s t h e r a t i o of

blanched weight t o i n i t i a l weight t i m e s one hundred. "So l ids l o s t

as product" r e p r e s e n t s t h e s o l i d s i n t h e b l anch water expressed on

t h e b a s i s of product e q u i v a l e n t s . For t h i s c a l c u l a t i o n i t w a s

assumed t h a t peas were 20% t o t a l s o l i d s , co rn w a s 25%, lima beans

were 32.5%, green beans were lo%, p o t a t o e s were 20.2%, c a r r o t s were

11.8% and b e e t s w e r e 12.7%. These v a l u e s are from USDA Handbook

No. 8.

The second t a b l e p r e s e n t i n g r a w d a t a on each b l anch ing run f o r each

product c h a r a c t e r i z e s t h e e f f l u e n t . A l l of t h e d a t a are expressed

as ppm o r % and r e p r e s e n t t h e c o n c e n t r a t i o n of t h e p a r t i c u l a r com-

ponent i n t h e e f f l u e n t . A more conven ien t way of e x p r e s s i n g t h e s e

d a t a f o r d i s c u s s i o n purposes i s t o e x p r e s s t h e water c h a r a c t e r i s t i c s

on t h e b a s i s of kkg. of processed product . This w a s done and s e l e c t e d

c h a r a c t e r i s t i c s w i l l be p re sen ted i n later d i s c u s s i o n s .

21

The n o t a t i o n used i n t h e t a b l e s t o d e s c r i b e t h e b l anch ing treatment is r e l a t i v e l y s t r a i g h t f o r w a r d . IQB s t a n d s f o r i n d i v i d u a l qu ick

b l anch , t h e "-0" o r "-number" r e p r e s e n t s t h e p red ry ing t r e a t m e n t (0 means no p red ry ing ; number expresses t h e % weight r e d u c t i o n i n p re -

d r y i n g ) , t h e "-sect' represents t h e h e a t on ly p rocess of IQB and deep

bed r e p r e s e n t s deep bed steam b lanch ing . Pipe r e f e r s t o p ipe b lanch-

i n g , t h e c o n t r o l .

Examination of t h e raw data shows t h a t several v a r i a b l e s had no

e f f e c t on b l anch ing c h a r a c t e r i s t i c s of t h e product . For peas t h e r e

d i d no t appear t o be an e f f e c t due t o var ie ty o r h a r v e s t d a t e on

b l anch ing c h a r a c t e r i s t i c s . T h e r e f o r e , t h e data w i t h i n one b l anch ing

t r e a t m e n t could be averaged t o s i m p l i f y p r e s e n t a t i o n . S i m i l a r l y w i t h

c o r n , t h e r e d i d no t appear t o be a n e f f e c t of harvest: d a t e . There-

f o r e , t h e d a t a were averaged w i t h i n each b l anch ing t r e a t m e n t . Lima

beans , g reen beans , p o t a t o e s , b e e t s and c a r r o t s a l s o showed no h a r -

vest da te e f f e c t . T h e r e f o r e , ave rages are used i n d i s c u s s i n g t h e

r e s u l t s . It should be po in ted o u t t h a t t h e v a r i a b l e h a r v e s t d a t e

i s n o t t h e s a m e as t h e v a r i a b l e m a t u r i t y . For example, a l though

co rn may be h a r v e s t e d on d i f f e r e n t d a t e s i t may be of t h e same ma-

t u r i t y and consequen t ly t h e r e can s t i l l be a m a t u r i t y e f f e c t .

co rn i n p a r t i c u l a r , i t might be suspec ted t h a t t h e r e would be a d i f -

f e r e n c e i n b l a n c h e r e f f l u e n t f o r mature v e r s u s immature co rn .

With

Although s e v e r a l parameters were measured on t h e b l a n c h e r e f f l u e n t

on ly a few w i l l be d i s c u s s e d . Probably t h e most impor tan t parameters

are BOD5, t o t a l o r g a n i c n i t r o g e n and t o t a l phosphorus

r e l a t i v e c o n c e n t r a t i o n s of t h e s e t h r e e components are used t o assess

t h e response of t h e waste t o b i o l o g i c a l waste t r e a t m e n t . Consequently

i n d i s c u s s i n g t h e d a t a , on ly t h e s e t h r e e parameters w i l l be d i s c u s s e d .

s i n c e t h e

22

PEA BLANCHING

A sunnnary of t h e pea b lanch ing d a t a is g iven i n Table 6.

b Blanching t rea tmen t

IQB-6 9

IQB-0

30 Sec

Deep bed

Pipe

Tab le 6.

E f f l u e n t g e n e r a t i o n (1. /kkg)

146

225

209

3 13

3 84

SUMMARY OF PEA BLANCHING DATA^

BOD5 (kg / k k d

1.8

2.6

2.5

4.3

3.0

T o t a l o rgan ic n i t r o g e n (kg /kkg)

0.09

0.13

0.13

0.22

0.17

T o t a l phosphorus

(kg /kkg)

0.02

0.04

0.03

0.05

0.05

Product y i e l d

(%I

88.8

89.3

90.4

83.3 --

S o l i d s l o s t as product

(%)

1.53

2.07

2.09

3.11 --

Expressed p e r kkg of blanched p roduc t . complete d a t a .

IQB-0 means I Q B w i t h o u t p red ry ing . 30 Sec means h e a t s e c t i o n o n l y of IQB. Deep bed means deep bed steam b lanch ing . P ipe means p i p e b l anch ing .

See Tables A 1 and A2 f o r a

bIQB-6.9 means IQB w i t h a 6.9% weight r e d u c t i o n p r i o r t o b l anch ing .

The f i r s t impor tan t o b s e r v a t i o n is t h a t a l l of t h e steam b lanch ing

methods r e s u l t e d i n less e f f l u e n t g e n e r a t i o n t h a n p i p e b l anch ing .

P red ry ing by a n ave rage of 6.9% weight r e d u c t i o n reduced waste genera-

t i o n by 62% w h i l e deep bed b l anch ing reduced t h e waste stream by 18%.

A s expec ted , p red ry ing showed less g e n e r a t i o n of waste than IQB o r

30 sec. h e a t t r e a t m e n t s . P red ry ing t h e s u r f a c e of t h e pea allowed

t h e condensed steam t o r e h y d r a t e t h e s u r f a c e r a t h e r t h a n running o f f .

The IQB-0 and 30 sec. h e a t t r e a t m e n t s r e s u l t e d i n n e a r l y t h e same

t o t a l e f f l u e n t g e n e r a t i o n i n d i c a t i n g t h a t most of t h e e f f l u e n t i s

gene ra t ed i n t h e h e a t s e c t i o n of IQB from steam condensa t ion .

The v a l u e of 225 l . / kkg (54 g a l / t o n ) r e p o r t e d h e r e f o r IQB-0 a g r e e s

q u i t e w e l l w i t h t h e 200 l . / kkg (48 g a l / t o n ) f o r steam b lanch ing peas

23

as r e p o r t e d by R a l l s e t a1.8 and w i t h t h e t h e o r e t i c a l v a l u e ob ta ined

when a mass b a l a n c e i s performed on t h e u n i t o p e r a t i o n . In R a l l s

e t a l . s t u d y t h e load ing r a t e w a s on ly 2 kg/m2 (0 .4 pound / f t ) of

b e l t s u g g e s t i n g t h a t t h e y had t h e e q u i v a l e n t of an IQB h e a t s t a g e .

The r e s i d e n c e t i m e , however, w a s much longe r than t h e 30 s e c . used

i n IQB.

2

The deep bed steam b lanch ing t r e a t m e n t r e s u l t e d i n 313 l . / kkg (75

g a l / t o n p r o d u c t ) , n e a r l y 50% more t h a n IQB b l anch ing . The g r e a t e r

e f f l u e n t g e n e r a t i o n i s due t o two f a c t o r s : 1) o v e r h e a t i n g of some

of t h e t i s s u e r e s u l t i n g i n g r e a t e r j u i c e l o s s and 2 ) a lower s u r f a c e

water h o l d i n g c a p a c i t y of t h e hea ted bed of peas .

i s e v i d e n t from t h e h i g h e r BOD5, n i t r o g e n and phosphorous v a l u e s

r e p o r t e d f o r t h e deep bed t r e a t m e n t . A l so , t h e s o l i d s l o s t as

product i s n e a r l y 50% more than f o r IQB. The second f a c t o r , lower

water h o l d i n g c a p a c i t y of t h e bed of peas, i s a r e s u l t of t h e h i g h e r

mass ave rage t empera tu re of t h e peas i n t h e deep bed t r ea tmen t .

With t h e r e s i d e n c e time of 2.5 minutes t h e bed t empera tu re w a s much

h i g h e r and consequen t ly t h e v i s c o s i t y of t h e water and t h e s u r f a c e

t e n s i o n of waterwere lower r e s u l t i n g i n more water running o f f .

The f i r s t f a c t o r

The 384 l . / kkg (92 g a l / t o n ) r e p o r t e d h e r e i s much lower than o t h e r

v a l u e s r e p o r t e d f o r water b l anch ing sys tems.

a waste water g e n e r a t i o n of 1420 l . / kkg (340 g a l / t o n ) f o r a p i p e

b l anch ing w h i l e Ra l l s e t a1.8 r e p o r t e d 4170 l . / kkg (1000 g a l / t o n )

f o r a d r a p e r - t y p e w a t e r b l anche r . The v a l u e r e p o r t e d h e r e r e f l e c t s

a ve ry impor tan t concept recognized by t h e canning p l a n t pe r sonne l .

They have c u t back t h e water make-up on a r e g u l a r b a s i s w h i l e con-

t i n u o u s l y checking p roduc t q u a l i t y .

water usage d r a s t i c a l l y through c o n t r o l on t h e p rocess .

v a l u e r e p o r t e d by Ra l l s e t a1.8 may n o t n e c e s s a r i l y r e f l e c t e x c e s s i v e

waste g e n e r a t i o n w i t h t h e d r a p e r - t y p e b l anche r . Rather i t may re-

f l e c t t h e ba t ch - type n a t u r e of t h e way i n which t h e experiment w a s

Weckel e t al.' r e p o r t e d

This has allowed them t o c u t

The h i g h

24

conducted. Perhaps more peas could have been processed i n t h e

blancher before t h e water had t o be changed. Also, a feed and bleed

system would reduce water usage.

The BOD reported h e r e f o r steam and pipe blanching corresponds q u i t e

w e l l t o t h e data of Ralls e t a l . . They reported a COD of 8 . 3 kglkkg

(16.6 lb / ton ) f o r steam blanching and i f w e assume a BODICOD r a t i o of

0.60 t h i s would r e s u l t i n a BOD of about 5 kg/kkg (10 l b / t o n ) . The 5 BOD/nitrogen/phosphorous r a t i o w a s s u r p r i s i n g l y cons tan t wi th an

average of 8214.411 (range 55-117/3.1-7.6/1.This i n d i c a t e s t h a t t h i s

waste h a s an adequate carbon t o n i t r o g e n t o phosphorous r a t i o f o r b i o l o g i c a l

t reatment .

8 5

F i n a l l y , t h e product y i e l d i s given i n Table 6. Product y i e l d w a s

q u i t e cons tan t between t h e IQB t reatments b u t deep bed steam blanch-

ing r e s u l t e d i n considerab y g r e a t e r l o s s of y i e l d . For deep bed

steam blanching t h i s lower y i e l d is due t o t i s s u e breakdown and

lower water holding c a p a c i t y of t h e peas , as explained e a r l i e r .

For IQB blanching most of t h e weight l o s s i s a l s o a r e s u l t of t h e

lower moisture holding capac i ty of t h e sur face . From experiments

done i n 1971, a cold pea can hold up t o 15% by weight as s u r f a c e

moisture. After blanching, t h e s u r f a c e is n e a r l y dry even though

steam has condensed on t h e sur face .

up t o 6% by weight as water and thus l o s s of s u r f a c e moisture would

account f o r up t o 9% weight l o s s .

The h o t s u r f a c e can hold only

The product y i e l d va lue would appear t o be too low f o r economic con-

s i d e r a t i o n of I Q B ; however, t h e process should be evaluated pr imar i ly

on t h e b a s i s of s o l i d s l o s t s i n c e t h i s va lue r e p r e s e n t s t r u e product

l o s s . Product y i e l d r e f l e c t s t h e loss of sur face water a s w e l l as

product loss . It would be a n t i c i p a t e d t h a t h o t water blanching

would r e s u l t i n even g r e a t e r s o l i d s l o s s as repor ted by Lee . 9

25

The r e s u l t s of o b j e c t i v e e v a l u a t i o n of peas i s shown i n Table 7.

It i s n o t i c e d t h a t ail cf t h e can vacuum v a l u e s f o r t h e e x p e r i m e n t a l l y

blanched samples are h i g h e r than t h a t f o r p i p e blanched samples. Th i s

i s due t o t h e f a c t t h a t t h e f i l l water t empera tu re w a s h i g h e r i n t h e

e x p e r i m e n t a l l y blanched samples . I n t h e l a b o r a t o r y t h e f i l l water

t empera tu re w a s n e a r 96 C (205 F) whereas i n t h e canning p l a n t i t

w a s 82-88 C (180-190 F) . Th i s d i f f e r e n c e could account f o r t h e

d i f f e r e n c e i n can vacuum. Th i s demons t r a t ed , however, t h a t peas

could be s u c c e s s f u l l y steam blanched p r i o r t o canning and t h a t t h e r e

w a s adequa te a i r removal from t h e t i s s u e . The can vacuum dec reased

s l i g h t l y upon s t o r a g e , as expec ted .

The d r a i n e d we igh t s of a l l steam blanched samples were h i g h e r t h a n

t h o s e of t h e c o n t r o l . This w a s n o t l i k e l y t h e r e s u l t of t h e b l anch ing

t r e a t m e n t b u t r a t h e r was t h e r e s u l t of a s l i g h t o v e r f i l l . The f i l l

weight w a s 292.5 g. (10.3 ounces) and t h e r e s u l t i n g d r a i n e d weight

averaged 320.9 g. (11.3 o u n c e s ) , a 28 g. (one ounce) weight g a i n

upon r e t o r t i n g and coo l ing .

Br ine sediment v a l u e s r e f l e c t a problem a s s o c i a t e d w i t h p red ry ing

p r i o r t o IQB. The b r i n e sediment v a l u e s w e r e c o n s i s t e n t l y h i g h e r

f o r t h e p r e d r i e d samples. This i s due t o s k i n s p l i t t i n g t h a t occu r s

d u r i n g p red ry ing and subsequen t ly comes o f f i n t h e a g i t a t e d r e t o r t

o p e r a t i o n . Compared t o p i p e b l anch ing , t h e o t h e r steam b lanch ing

systems are q u i t e a c c e p t a b l e .

F i n a l l y , t h e p e r c e n t s p l i t d a t a are p resen ted . Although t h e p e r c e n t

s p l i t i s h i g h e r f o r t h e steam blanched samples , t h i s a p p a r e n t l y w a s

no t d e t r i m e n t a l t o p roduc t q u a l i t y . The b r i n e sediment v a l u e d i d

no t seem t o r e f l e c t t h e s p l i t damage. Greater p e r c e n t s p l i t s i n

steam b lanch ing compared t o water b l anch ing may r e f l e c t t h e d i f -

f e r e n c e i n h e a t i n g rates. With steam b lanch ing t h e t empera tu re

i n c r e a s e s v e r y r a p i d l y r e s u l t i n g i n a r a p i d e x p u l s i o n of t i s s u e

26

Table 7. SUMMARY OF OBJECTIVE EVALUATION OF PEASa

Avg. 32.0

30.2

29.7

29.5

17.5

Blanch- ing

treat- ment

Range 27.9-36.1

24.4-36.8

25.4-31.8

26.4-31.5

10.2-24.9

IQB-6.9

IQB 30 Sec

Deep

Pipe

bed

322.6

318.6

312.7

332.3

301.6

IQB-6.9

I Q B

30 Sec

Deep

Pipe

bed

315.8-328.C

314.4-320.9

309.0-315.5

325.7-337.7

293.4-305.6

IQB-6.9

IQB

30 Sec

Deep

Pipe

bed

6.29

3.82

4.09

3.96

5.30

Can Vacuum (cm. Hg. vacuum)

Months of s torage

5.05-8.18

3.69-3.91

2.97-5.06

2.45-6.12

3.23-8.76

320.4 312.1-324.3 316.4 311.0-323.2

315.8 308.4-320.1

33 7.4 326.6-343.6

!95.1 L 285.7-305.6

5.05-10.36

3.88-4.56 2.81-5.23

3.45-4.37

2.36-5.27

5.41 3.81

3.41

4.07

4.05

326.8

319.2 313.5

337.4

301 .O

Range 20.6-38.4

20.8-41.1

18.3-36.8

23.4-34.5

13.7-28.4

Avg . 31.5

32.0

28.4

28.4

20.8

6

Range 22.1-36.8

22.4-38.4

21.6-31.8

19.8-33.3

16 .O-26.9

7.23

4.23

3.73

3.83

3.59

Drained Weight (g. 1

315.8-337.1

3 11.3 -326.9

307.6-317.5

329.4-345.3

291.1-307.0

5.24-5.57 3.44-4.17

2.98-3.81

3.28-5.06

2.15 - 7.00

320.4 320.1

315.0

334.3

302.5

4.59

3.38

4.80

3.13

3.89

313.0-324.6

311.5-328.0

309.8-318.4

326.6-341.9

299.1-305.9

4.46-4.72

3.33-3.43

1.79-8.30

2.88-3.39

2.16-6.08

a Each average cons i s t s of a t least n ine observat ions.

27

Table 7 Blanch-

ing t reat-

ment

IQB-6.9

IQB 30 Sec

Deep bed

Pipe

:continued). SUMMARY OF OBJECTIVE EVALUATION OF PEASa S p l i t s i n Peas

Avg. Range 38 30-48

28 26-30

36 29-40

40 32-56

18 14-29

Months of Storage 6 9

Avg. Range 35 29-39

41 39-43

36 29-43

33 28-39

22 13-29

Avg. Range 35 26-45

30 24-34

27 21-37

28 19-37

21 14-27

Avg . Range 30 26-35

24 19-30

30 20-40

29 23-34

20 16-25

a Each average c o n s i s t s of a t least n i n e observat ions.

gases . This sudden expansion of gases may f r a c t u r e i n t h e peas

r e s u l t i n g i n eventual s p l i t t i n g . With water blanching, on t h e o t h e r

hand, t h e temperature r i se i s slow enough t o a l low t i s s u e gases t o

d i f f u s e ou t of t h e t i s s u e without developing excessive pressures .

A sunnnary of t h e s u b j e c t i v e eva lua t ion of peas i s given i n Table 8.

From these d a t a it i s concluded t h a t steam blanching r e s u l t e d i n a

canned pea product a t least as good as t h a t produced wi th pipe blanch-

ing. I n those cases where t h e r e w a s a s i g n i f i c a n t d i f f e r e n c e , t h e

steam blanched product w a s g e n e r a l l y prefer red .

I n conclusion, t h e s tudy wi th peas i n d i c a t e s t h a t IQB can be success-

f u l l y used f o r pea blanching wi th a 40% decrease i n l i q u i d waste genera t ion

compared t o pipe blanching. Compared t o deep bed steam blanching,

IQB produced 28% less e f f l u e n t and less product l o s s . IQB wi th pre-

drying i s not recommended due t o s i g n i f i c a n t increases i n b r i n e

sediment. Product q u a l i t y as evaluated by o b j e c t i v e and tas te panel

tests w a s a t least as good fo r IQB as f o r pipe blanching.

CORN BLANCHING

A s u m a r y of t h e corn blanching d a t a is given i n Table 9.

28

Table 8. SUMMARY OF SUBJECTIVE EVALUATION OF PEAS

a IQB-6.25 means IQB wi th a 6.25% weight reduct ion p r i o r t o blanching. IQB-0 means IQB without predrying. 30 Sec means heat only s t age of IQB. Deep bed means deep bed steam blanching. 4 o r 3 r e f e r s t o s ieve s i z e ; Per fec t ion was s ieve s i z e 3 , 4 and 5. A l s means A l s w e e t ; A l a means Alaskan; Perf . means Perfect ion.

w a s canned the same day as the experimental sample. The top number i s the l eve l of s ign i f i cance and the bottom three numbers represent number of judges p re fe r r ing experimental sample, con t ro l and no preference, respec t ive ly . NS means no s i g n i f i c a n t d i f fe rence .

bEach sample w a s compared t o a pipe-blanched, canned con t ro l . The con t ro l

29

Table 9. SUMMARY OF CORN BLANCHING DATAa

E f f luen t genera t ion

(1. /kkp) b Blanching t reatment

IQB-7.5

I Q B - 0

20 Sec

Deep bed

Pipe

Tota l So l ids organic Tota l Product 10s t a s

BOD5 ni t rogen phosphorus y i e l d product (kg/kkg) ( kpylkkg) (kg /kkn ) (% (% )

1.4 2.7

3.0

4.4

4.9

86

125

125

163

730

0.017 0,008 93.1 0.81

0.039 0.020 97 .1 1.61

0.037 0.019 97.4 1.52

0.049 0.028 94.2 2.42

0.089 0.034 -- -- I I I I I

a

bIQB-7.5 means IQB with a 7.5% weight reduct ion p r i o r t o blanching.

Expressed p e r kkg of blanched corn. See Tables A3 and A4 f o r complete data .

IQB-0 means IQB without predrying. 20 Sec means hea t s ec t ion only of I Q B . Deep bed means deep bed steam blanching. Pipe means pipe blanching.

A s wi th pea blanching, a l l of t he steam blanching methods produced

less e f f l u e n t than p i p e blanching. IQB without predrying reduced

e f f l u e n t genera t ion by .83% compared t o p i p e blanching while a 7.5%

weight reduct ion p r i o r t o IQB reduced e f f l u e n t genera t ion by 88%.

The e f f l u e n t generated p e r ton of corn i s considerably less than t h a t

f o r peas because of t he d i f f e r e n c e i n t h e na tu re of t h e su r face of

t he two vegetab les . Cut corn su r faces expose s t a r c h which upon hea t -

ing can absorb water r e s u l t i n g i n less water l o s s . On t h e o the r

hand, t h e BOD5 f o r corn was about t h e same as t h a t f o r peas ind i -

c a t i n g t h a t water t h a t d i d d r a i n of f corn c a r r i e d wi th i t more

s o l i d s .

t h a t f o r peas. This r e f l e c t s t h e f a c t t h a t with corn , t h e blanching

process i s pr imar i ly a wash s t e p t o remove reducing sugars and o the r

components t h a t may con t r ibu te t o brown co lo r development during

thermal processing. In some p l a n t s , corn i s not blanched p r i o r t o

I n p ipe blanching, water usage f o r corn was nea r ly double

1 canning. Weckel e t a l . reported an average of 1043 l . /kkg

30

(250 ga l / ton ) f o r p ipe blanching corn.

blanching r e s u l t e d i n g r e a t e r e f f l u e n t genera t ion than IQB bu t i t

was s t i l l cons iderably less than p ipe blanching.

A s w i t h i peas , deep bed steam

The BOD/N/P r a t i o f o r corn averaged 151 /2 .1 /1 (range 88-237/1 .5-2 .9 /1)

i n d i c a t i n g tha t the waste may b e low i n n i t rogen f o r b i o l o g i c a l

t reatment . From Table A 4 the BOD/COD r a t i o was 0 . 7 8 . Soderquis t

e t a1.l' repor ted a BOD/COD r a t i o of 0.75 f o r corn wastes.

f i g u r e , however, included waste generated a t u n i t opera t ions i n ad-

d i t ion t o blanching . That

With r e spec t t o product y i e l d there a re some i n t e r e s t i n g observa-

t i ons . F i r s t , wi th predrying t h e product y i e l d i s lower than w i t h

IQB without predrying. This r e f l e c t s the f a c t t ha t the corn su r face ,

once dehydrated, is very d i f f i c u l t t o rehydra te and thus t h i s y i e l d

r e f l e c t s l o s s e s of product s o l i d s and l o s s of reabsorbing capac i ty

of t h e sur face . Deep bed steam blanching r e s u l t e d i n g r e a t e r product

loss pr imar i ly through s o l i d s l o s t i n the e f f l u e n t .

Table 10 p resen t s the r e s u l t s of the o b j e c t i v e eva lua t ion on steam

blanched and p ipe blanched corn. As wi th peas , can vacuum f o r the

steam blanched samples i s h ighe r than t h a t f o r t h e pipe blanched

sample. This r e f l e c t s t h e lower water f i l l temperature used i n the

canning p l a n t compared t o t h e labora tory p i l o t p l an t . There was no

s i g n i f i c a n t d i f f e r e n c e i n drained weight between any of t h e samples.

A s u m a r y of the s u b j e c t i v e eva lua t ion of corn i s given i n Table 11.

There appears t o be a s i g n i f i c a n t d i f f e r e n c e between steam blanched

and p ipe blanched samples bu t the preference i s not cons i s t en t . It

was observed tha t the steam blanched samples were darker i n c o l o r

than the p ipe blanched samples a t t e s t i n g t o the f a c t t h a t the blanch

s t e p is p r imar i ly a wash s t e p f o r corn. This da rke r c o l o r , however,

d id n o t man i fe s t i t s e l f i n consumer preference meaning tha t perhaps

31

blanching does not have t o serve as a wash s t e p i f the consumer cannot

de t ec t t he co lor d i f fe rence .

Avg . 26.9

31.8

28.2

26.4

23.6

Table 10. SUMMARY OF OBJECTIVE EVALUATION OF CORNa

Range

21.6-30.7

29.0-35.1

23.6-36.6

22.6-31.8

18.5-28.7

Blanch- ing

treat- men t

IQB - 7.5

IQB 20 Sec

Deep bec

Contro 1

IQB- 7.5

IQB

20 Sec

Deep bec

Con t r o 1

Can Vacuum (cm. Hg. vacuum)

Months of Storage

327.7

324.6

325.5

331.7

327.2

326.9-294.1

322.6-327.7

320.9-330.9

330.3-332.8

310.4-343.1

3

Avg . 27.9

32.5

32.3

31.0

18.5

b

6 9 I

Avg . 21.8

26.7

23.6

20.6

17.5

Range

15.2-27.4

20.8-34.8

19.1-31.8

14.5-31.2

16.5-19.6

Drained Weight

328.0b

317.8

317.2

326.9

304.4

326.9

318.4

315.8

327.7

324.6

321.8-330.3

315.8-320.1

314.7-317.2

322.6-330.3

315.8-339.4

Avg . 23.1

27.7

27.7

24.6

22.6

322.9

323.5

321.2

330.3

322.1

Range

21.6-25.4

25.4-32 .O

22.6-34.3

51.8-31.8

17.8-26.2

317.8-329.4

316.1-328.3

320.6-322.1

328.3-332.3

313.5-337.1

a

bOnly one series of samples w a s evaluated a f t e r th ree months' s torage. Each average cons i s t s of a t l e a s t nine observat ions.

In conclusion, IQB and deep bed steam blanching both r e s u l t i n

d r a s t i c reduct ions of e f f l u e n t generat ion i n corn blanching. How-

ever , i n both cases a darker product r e su l t ed a f t e r r e t o r t i n g . To

maintain a b r igh t golden yellow co lo r , corn would have t o be thor-

oughly washed p r i o r t o steam blanching.

de fea t s the purpose of steam blanching s ince the wash s t e p would

c r e a t e another high volume-low load e f f l u e n t steam. Therefore, the

This wash s t e p , i n tu rn ,

32

Table 11. SUMMARY OF SUBJECTIVE EVALUATION OF CORN

Blanching t rea tmen ta

IQB-7.5

IQB-0

20 Sec

Storage t i m e (months)b 1 3 6 9

1% 1% 0.1%

5% 0.1% 5% 3-8-5 0-11-3 NS 3-4-6

1% 1% NS 9-4-1 NS 2-9-4 5% 0.1%

4-10-4 4-7-3 2-17-4 NS

Deep bed I 3-8-3

I 2-12-7 I 6-6-5 I I ’ 1%

-- IQB-7.5 I 8-13-1

6-9-1 I NS I NS

IQB - 0 I NS

I I I I - - 3-7-2 10-6-2 1 %

20 Sec NS

NS 7-3-6 - -

Deep bed NS 7-9-2 I NS -- IQB- 7.5 I 8-5-4

advantage of producing a b r i g h t yellow corn must be weighed a g a i n s t

t h e disadvantage of c r e a t i n g an e f f l u e n t stream and t h e c o s t of i t s

subsequent t reatment . Since blanching of corn must be done when

corn is packed i n t o No. 10 cans, t h e r e i s s t i l l a use f o r steam

blanching . 33

I 10-6-5 I 18-3-4 -- IQB-0

20 Sec

Deep Bed

10-8-0 -- 9-7-2 5-16-4 0.1% 0.1%

18-3-1 -- NS 16-3-3 0.1% 0.1% 0.1%

17-2-0 -- 11-7-2 11-5-3

LIMA BEANS

Lima bean blanching r e s u l t s are summarized i n Table 12.

To ta l o rganic n i t rogen (kg Ikkp )

0.02

0.12

0.06

0.17

0.02

Table 12. SUMMARY OF LIMA BEAN BLANCHING DATAa

Tota l Product phosphorus y i e l d

(kg Ikkg ) (%)

0.004 97.5

0.02 93.4

0.015 96.7

0.04 88.7 0.01 --

Blanching t reatmentb

IQB-5 .O

IQB - 0

20 Sec

Deep bed

Pipe

Ef f luen t genera t ion

(l . /kkg)

67

171

133

238

82 1

BOD^ 5 kg 1 kkg )

0.35

1.7

2.4

3.5

0.65 I I

Sol ids l o s t as product

(% )

0.24

0.86

0.54

1.38 --

a Expressed p e r kkg of blanched product. See Tables A5 and A6 f o r complete da t a .

bIQB-5.0 means IQB wi th a 5.0% weight reduct ion p r i o r t o blanching. IQB-0 means IQB without predrying. 20 Sec means hea t s e c t i o n only of I Q B . Deep bed means deep bed steam blanching. Pipe means p ipe blanching.

Resul t s wi th lima beans p a r a l l e l those obtained wi th peas and corn.

The e f f l u e n t genera t ion va lues a r e s i m i l a r t o those repor ted f o r

corn i n Table 9 and r e f l e c t s t h e water hold ing capac i ty of t h e s u r -

f ace of the lima bean. I n lima bean processing t h e blanch s t e p

serves t o p a r t i a l l y rehydra te the dry l i m a bean seeds.

The p ipe blanching method produced 821 l . /kg (197 g a l l t o n ) compared

t o only 171 l . /kg (41 ga l / t on ) f o r IQB; IQB reduced e f f l u e n t by 79%.

Predrying reduced t h e e f f l u e n t t o only 8% of t h a t f o r pipe blanching.

The BODINIP r a t i o averaged 9714.811 (range 32-205/1.1-7.811) i n d i c a t i n g

t h a t lima bean blancher e f f l u e n t has an adequate n u t r i e n t balance f o r

34

b i o l o g i c a l waste t reatment . The BOD/COD r a t i o was 0.76 (ca lcu la ted

from Table A6). Product y i e l d f i g u r e s i n d i c a t e t h a t l i m a beans re-

hydra te r e a d i l y a f t e r t h e predrying s t e p s i n c e t h e y i e l d i s g r e a t e r

than t h a t f o r t h e o t h e r steam blanching methods. The d i f f e r e n c e

between t h e y i e l d values f o r IQB-0 and 20 sec r e f l e c t product l o s s

and l i q u i d l o s s i n t h e hold s e c t i o n dur ing IQB. The only d i f f e r e n c e

between t h e s e two runs i s t h e f a c t t h a t t h e 20 sec experiment d i d

not include t h e hold s e c t i o n . The l i q u i d l o s s occurr ing i n the hold

s e c t i o n i s a l s o r e f l e c t e d i n t h e h igher e f f l u e n t genera t ion value

reported f o r IQB-0 compared t o 20 sec. Deep bed steam blanching

r e s u l t e d i n t h e lowest y i e l d and i s p a r t i a l l y accounted f o r i n the

s o l i d s l o s t . The o t h e r l o s s i s accounted f o r i n t h e decreased water

holding capac i ty of t h e s u r f a c e due t o a h igher mass average t e m -

p e r a t u r e of t h e deep bed blanched lima beans.

Resul t s of t h e o b j e c t i v e eva lua t ion of l i m a beans i s given i n Table

13. It can be seen t h a t can vacuum of a l l of t h e steam blanched

samples i s considerably lower than t h a t f o r pipe blanched, canned

product. This may have been due i n p a r t t o can o v e r f i l l i n t h e

experimental samples. Notice t h a t most of t h e drained weights are

g r e a t e r f o r t h e experimental ly blanched samples i n d i c a t i n g t h a t t h e

can w a s o v e r f i l l e d . Upon r e t o r t i n g t h e lima bean absorbs water and

expands. This can r e s u l t i n decreased can vacuum. Thus, t h e lower

can vacuum f o r t h e steam blanched samples does n o t n e c e s s a r i l y re-

f l e c t poor t i s s u e gas removal. The somewhat h igher (8-10%) drained

weights f o r t he s t e a m blanched samples could be cor rec ted by

f i l l i n g a t approximately 227-241 g.(8-8.5 ounces) r a t h e r than t h e

c u r r e n t 256 g. (9.0 ounces) f i l l weight. Proper drained weight

would then be achieved following r e t o r t i n g and can vacuum would

probably be higher .

Although i t w a s not

suspended s o l i d s i n

recorded, t h e r e appeared

the IQB predried sample.

35

t o be more sk ins and

This w a s presumably

Table 13. SUMMARY OF OBJECTIVE EVALUATION OF LIMA BEANS

381.4-413.6

299.6-315.0

277.8-315.8

338.7-343.5

Blanch- ing

t reat- ment

IQB - 5.0

IQB

20 Sec

Deep

Pipe

bed

IQB-5.0

IQB

20 Sec

Deep bed

Pipe

368.3

317.8

303.6

341.1

Can Vacuum (cm. Hg. vacuum)

Months of Storage

(g.1 362.3-373.2 386.0 372.8-394.9

295.1-340.2 338.5 296.8-380.3

283.4-323.5 298.2 279.7-317.5

335.0-343.9 341.1 336.9-345.3

Avg . 15.0

15.7

12.7

12.4

400.4

334.3

301.3

344.2

1

11.4-21.6 9.7-21.6

12.2-13 .O 6 4-20.3

Range

298.2-317.2 05.6

29.7 28.7-31.2 I

293.7-311.8

1

395.3

307.3

296.8

341.7

324.0

a Each average

- Avg . 17.0

17.8

17.0

16.3

30.5

298.2-364.9 07.9 2

'1

Range 15.2-19.1

13.5-21.8

14.5- 19.6 14.0-19.1

29.7-31.8

Avg . 17.0

18.8

17.8

13.7

28.7

6 Range

10.2-20.3 14.7-22.6

14.2-21.1

10.2-17.9

28.2-29.2

15.7

14.5

15.2-16.3

8.9-17.8

27.4 26.7-28.4 . I Drained Weight

cons i s t s of a t least three observat ions.

374.5-414.7

299.9-368.6

278.6-324.0

338.0-349.7

306.7-319.8

due t o the rupture of sk ins during drying which were released during

t h e ag i t a t ed cook. On t h i s b a s i s i t i s doubtful i f I Q B w i t h pre-

drying i s an acceptable process.

Subject ive eva lua t ion of lima beans i s presented i n Table 14. There

w a s no clear t rend i n preference f o r e i the r steam blanched o r pipe

blanched product. This probably r e f l e c t s the f a c t t ha t people

usua l ly do no t have a s p e c i f i c idea of what good l i m a beans are

supposed t o taste o r look l i k e . The conclusion can be made tha t

there i s probably a d i f f e rence bu t t ha t i t w a s no t a s t r i k i n g enough

36

Table 14. SUMMARY OF SUBJECTIVE EVALUATION OF LIMA BEANS

B l anch ing trea tmen ta

S to rage Timeb (months) 1 3 6 9

0.1% 0.1% I 1% I IQB-5.0 I 9-6-1

0.1%

Deep Bed I NS I NS I 8-4-9 I 5-4-11 0.1%

8-6-3 8-5-4 NS 0.1% 0.1%

IQB-0 NS 6-8-5 NS NS 0.1% 0.1% 0.1%

d i f f e r e n c e t o a l low development of a p re fe rence .

f i c a t i o n f o r d i s c a r d i n g any of t h e steam b lanch ing methods based on

s u b j e c t i v e e v a l u a t i o n .

There is no j u s t i -

I n c o n c l u s i o n , IQB wi thou t p red ry ing can be s u c c e s s f u l l y a p p l i e d t o

lima beans. Adjustment must be made i n f i l l weight t o a r r i v e a t t h e

c o r r e c t d ra ined weight s i n c e t h e r e i s more r e h y d r a t i o n i n the can

w i t h IQB blanched beans. Predry ing r e s u l t s i n a g r e a t e r r e d u c t i o n

i n e f f l u e n t g e n e r a t i o n ; however, p red ry ing a d v e r s e l y a f f e c t s product

q u a l i t y due t o s k i n s p l i t t i n g .

GREEN BEAN BLANCHING

Table 15 p resen t s a summary of t h e green bean blanching r e s u l t s ,

Blanching t reatment

IQB - 0

Deep bed

Pipe

Table 15. SUMMARY OF GREEN BEAN BLANCHING DATAa

To ta l E f f luen t organic

genera t ion BOD n i t rogen (l . /kkp) (kg/kl?g) (kg/kkg)

163 1.0 0.03

125 0.55 0.015

334 -- --

Tota l phosphorus

0.008

0.005

(kg /kkp)

--

Product y i e l d

(%)

94.0

97.3 --

Sol ids l o s t as product

(%I 1.16

0.89 --

a Expressed p e r kkg of blanched product. See Tables A7 and A 8 f o r complete da ta . A l l p ipe blanching ana lyses were d iscarded due t o inappropr ia te sample s torage .

Deep bed means deep bed steam blanching. Pipe means p ipe blanching.

bIQB-O means IQB without predrying.

I n green bean blanching, steam blanching r e s u l t e d i n a 51-63%

decrease i n e f f l u e n t genera t ion compared t o p ipe blanching. With

green beans there w a s a d i f f e r e n t t rend than with the previous ly

blanched products . I n pea, corn o r l i m a bean blanching the deep

bed steam blanching t reatment always r e s u l t e d i n a g r e a t e r genera-

t i o n of e f f l u e n t . With green beans the oppos i te i s t r u e ; tha t i s ,

deep bed blanching r e s u l t e d i n less e f f l u e n t than IQB-0. This re-

f l e c t s the p e c u l i a r na tu re of green bean blanching i n tha t the

maximum temperature reached was 79 C (175 F) . I n green bean blanch-

ing , t h e bean must reach a t least 63 C (145 F) bu t must no t exceed

82 C (180 F) i n o rde r t o ac t iva te the enzyme p e c t i n methyl esterase (PME).

This enzyme, once a c t i v a t e d , w i l l c l eave methoxy groups from pec t in

i n t h e ou te r l a y e r a l lowing calcium-pectin i n t e r a c t i o n and conse-

quent ly no sloughing. In both deep bed and IQB the mass average

temperature was between 77 C (170 F) and 82 C (180 F). Consequently

38

t h e r e was no d i f f e r e n c e i n t h e amount of steam r e q u i r e d f o r h e a t i n g .

A l so , s i n c e t h e r e was no d i f f e r e n c e i n t empera tu re bo th t r e a t m e n t s

should have r e s u l t e d i n e q u i v a l e n t s u r f a c e wa te r -ho ld ing c a p a c i t y .

However, i n deep bed steam b lanch ing t h e r e was a g r e a t e r water-

h o l d i n g c a p a c i t y i n t h e bed i t s e l f r e s u l t i n g i n less e f f l u e n t d r a i n -

i ng from t h e p rocess .

Ral ls e t a1.8 r e p o r t e d e f f l u e n t g e n e r a t i o n of 196 l . / kkg (47 g a l / t o n )

f o r steam b lanch ing and 7080 l . /kkg (1700 g a l / t o n ) f o r water b lanch-

i n g .

Deep Bed r e p o r t e d h e r e and, i n t h e case of steam b l a n c h i n g , may b e

due t o b l anch ing i n 100 C steam r a t h e r t han a steam-air m i x t u r e a t

79-82 C (175-180 F).

b l anch ing system may r e f l e c t t h e f a c t t h a t ba t ch - type exper iments

were conducted and perhaps much more p roduc t could have been proc-

essed b e f o r e t h e b l a n c h e r water had t o be changed. A l so , f eed and

b l eed systems may be more e f f i c i e n t from a waste g e n e r a t i o n s t a n d -

p o i n t t han s t r a i g h t b a t c h systems. S o d e r q u i s t e t a1.l' r e p o r t e d

446 l . / k k g (107 g a l / t o n ) f o r a r o t a r y steam b lanche r . This compares

q u i t e f a v o r a b l y t o t h e 334 l . / kkg (80 g a l / t o n ) r e p o r t e d h e r e f o r

p i p e b l anch ing .

Both of these v a l u e s are c o n s i d e r a b l y h i g h e r t h a n t h e IQB-0 and

The exceed ing ly h i g h v a l u e f o r t h e water

The BOD/N/P r a t i o ' f o r g reen bean b l a n c h e r e f f l u e n t w a s 114/3 .8 /1

(range 105-129/2.7-7.4/1)indicating t h a t t h e l i q u i d waste stream

probably c o n t a i n s adequa te n i t r o g e n and phosphorus f o r b i o l o g i c a l

t r ea tmen t .

f o r t h e r o t a r y b l anch ing o p e r a t i o n and a BOD/COD r a t i o of 0.53.

S o d e r q u i s t e t a1.l' r e p o r t e d a BOD/N/P r a t i o of 109 /6 /1

5 P red ry ing was n o t a t t empted i n t h i s s t u d y s i n c e r e s u l t s i n 1971

had shown t h a t even w i t h a 6% weight r e d u c t i o n s k i n r u p t u r e was

seve re . With p r e d r y i n g t o less t h a n 6%, t h e s a v i n g s i n e f f l u e n t

38

g e n e r a t i o n would n o t j u s t i f y t h e c o s t of p red ry ing . T h e r e f o r e ,

p red ry ing p r i o r t o I Q B i s no t recommended f o r green beans.

Table 16 summarizes t h e o b j e c t i v e e v a l u a t i o n s performed on g reen

beans. Can vacuum was n o t i c e a b l y lower f o r t h e two steam blanched

samples compared t o p i p e blanched samples. This w a s p robably due

t o b r i n e o v e r f i l l i n t h e e x p e r i m e n t a l l y b lanched samples s i n c e t h e can

vacuum v a l u e s do n o t f o l l o w any p a t t e r n w i t h s t o r a g e t i m e . I f t h e

poor can vacuum had been due t o p re sence of a i r ce l l s i n t h e g reen

bean t i s s u e , t h e can vacuum v a l u e s would have dec reased upon s t o r a g e .

In s t ead t h e can vacuum a c t u a l l y i n c r e a s e d upon s t o r a g e f o r t h e IQB

sample and f l u c t u a t e d f o r t h e deep bed sample. There was no s i g -

n i f i c a n t d i f f e r e n c e i n d r a i n e d weight between any of t h e t r e a t m e n t s .

For s lough and p e r c e n t s p l i t s , however, IQB w a s d e f i n i t e l y s u p e r i o r

t o bo th deep bed steam b lanch ing and p i p e b l anch ing . These low

v a l u e s are i n d i c a t i v e t h a t PME had been a c t i v a t e d . With deep bed

steam b lanch ing t h e s u r f a c e t empera tu re of t h e t i s s u e may have been

over 180 F f o r s h o r t p e r i o d s of time r e s u l t i n g i n PME i n a c t i v a t i o n .

Deep bed steam b lanch ing compares f a v o r a b l y t o p i p e b l anch ing .

S u b j e c t i v e e v a l u a t i o n of green beans i s sumnarized i n Table 1 7 .

From t h e s e d a t a it is a p p a r e n t t h a t t h e r e i s no real p r e f e r e n c e f o r

product blanched i n steam o r h o t water. Even though t h e o b j e c t i v e

tes ts i n d i c a t e d c o n s i d e r a b l y less s lough and p e r c e n t s p l i t s f o r I Q B ,

t h e tas te panel could n o t p i c k o u t t h a t c h a r a c t e r i s t i c as a b a s i s

f o r e s t a b l i s h i n g p r e f e r e n c e . Th i s p o i n t s o u t t h e f a l l a c y of u s i n g

on ly o b j e c t i v e o r s u b j e c t i v e tes ts t o e v a l u a t e i n n o v a t i v e o r new

p rocess ing t echn iques .

I n c o n c l u s i o n , IQB and deep bed steam b lanch ing can be used t o

b l anch g reen beans p r i o r t o canning . A steam-air m i x t u r e a t 77-82 C

(170-180 F) i s r e q u i r e d t o a c t i v a t e €'ME. IQB produced 51 p e r c e n t

40

Table 16. SUMMARY OF OBJECTIVE EVALUATION OF GREEN BEANSa

Blanching t reatment

I Q B

Deep Bed

Pipe

Months of S to rage 1 3 6 9

Aver. Range Aver. Range Aver. Range Aver. Range

1 .0 0-5.1 0.0 0-0 3 .1 0-7.6 4 . 1 0-8.9

0.8 0-1.3 6.9 2.5-12.7 1 .5 0-7.6 8.9 5.1-14.0

17.0 15.2-17.8 16.3 12.7-19.1 17.0 16.5-17.8 17.0 16.5-19.1

I Q B

P ipe

I Q B Deep Bed

P ipe

Drained Weight

5.0 5.0-5.0 2.5 0-5.0 5.0 5.0-5.0 15.0 10.0-20.0

32.5 30.0-35.0 30.0 25.0-35.0 35.0 30.0-40.0 22.5 20.0-25.0

52.5 35.0-70.0 55.0 50.0-60.0 22.5 20.0-25.0 55.0 55.0-55.0

I Q B Deep Bed 12.0-15.0

Pipe 6.5-9.0

Slough ( X )

8 .0 8.0-8.0 7.0 7.0-7.0 10.0 9.0-11.0

16.0 14.0-18.0 16.0 15.0-17.0 15.0 15.0-15.0

16.0 16.0-16.0 11.0 9.0-13.0 15.0 14.0-16.0

S p l i t s

less e f f l u e n t than p ipe blanching and r e s u l t e d i n considerably less

slough and pe rcen t s p l i t s . Organo lep t i ca l ly , t h e steam blanched

products were q u i t e accep tab le .

41

Table 17. SUMMARY OF SUBJECTIVE EVALUATION OF GREEN BEANS

Blanching t reatmenta

IQB - 0

Deep bed

s t o r a g e t i m e D (months )

1 3 6 9

0.1% 5% 5% 10-5-5 6-3-4 NS 6-6-4

1% 1% 1% NS 5-6-3 5-8-3 5-6-6

POTATO BLANCHING

T o t a l E f f l u e n t o rgan ic

Blanching gene ra t ion BOD5 n i t r o g e n t reatmentb , (1. /kkp) (kg/kkg) , ( kg/kkp)

IQB-6.9 100 0.5 0.03

I Q B - 0 1 7 1 0.75 0.05

Deep bed 167 0.65 0.065

Po ta to blanching d a t a are summarized i n Table 18.

Table 18. SUMMARY OF POTATO BLANCHING DATAa

S o l i d s T o t a l Product l o s t as

phosphorus y i e l d product (kg /kkg ) (%) (%)

0.0085 93.1 0.43

0.012 93.4 0.60

0.017 93.8 0.61

Expressed p e r kkg of blanched product. See Tables A9 and A10 f o r complete da t a .

bIQB-6.9 means IQB wi th a 6.9% weight r e d u c t i o n p r i o r t o blanching. IQB-0 means IQB wi thou t predrying. Deep bed means deep bed steam blanching.

a

4 2

Since p o t a t o e s are n o t normal ly blanched fo l lowing s l i c i n g o r d i c i n g

t h e r e i s no water b l anch ing method t o which t o compare t h e steam

b lanch ing method. However, t h e s e exper iments were inc luded f o r

t hose p r o c e s s o r s who b o t h can and f r e e z e o r dehydra t e p o t a t o e s .

P r i o r t o f r e e z i n g o r d e h y d r a t i o n , p o t a t o e s may h e b ianched . The

d a t a f o r e f f l u e n t g e n e r a t i o n are q u i t e similar t o t h o s e p re sen ted

f o r c o r n and r e f l e c t t h e wa te r -ho ld ing c a p a c i t y of t h e c u t p o t a t o

s u r f a c e . The BOD5 gene ra t ed p e r t o n of product i s q u i t e low sug-

g e s t i n g t h a t most of t h e f r e e s u r f a c e c e l l u l a r j u i c e s were washed

o f f t h e p o t a t o p r i o r t o b l anch ing . Th i s prewashing was accomplished

by t r a n s p o r t i n g the p o t a t o e s t o t h e l a b o r a t o r y under water and then

washing them a g a i n i n the p i l o t p l a n t . Deep bed and IQB-0 r e s u l t e d

i n n e a r l y t h e same e f f l u e n t g e n e r a t i o n . This w a s due t o t h e f a c t

t h a t pe rox idase i n a c t i v a t i o n i n t h e p o t a t o s l i ce r e q u i r e d a h e a t

time of 60 seconds r e s u l t i n g i n a m a s s ave rage t empera tu re n e a r 93 C

(200 F ) . Thus, compared t o deep bed steam b lanch ing where t h e mass

ave rage tempera ture w a s between 93-99 C (200-210 F ) , t h e r e would be

l i t t l e d i f f e r e n c e i n t h e t o t a l steam condensed. Consequent ly , t h e r e

w a s l i t t l e d i f f e r e n c e between deep bed and IQB. The h e a t o n l y sec-

t i o n of t h e IQB p rocess was n o t r u n w i t h p o t a t o e s o r any of t h e r o o t

c rops .

that IQB-0 and t h e hea t -on ly r u n s d i d n o t d i f f e r s i g n i f i c a n t l y i n

e f f l u e n t g e n e r a t i o n s i n c e l i t t l e e f f l u e n t w a s released i n t h e ho ld

s e c t i o n . A l s o , f o r t h e r o o t c r o p s b l anch ing is u s u a l l y r e q u i r e d

p r i o r t o f r e e z i n g t o p a r t i a l l y cook t h e product .

cumstances t h e hea t -on ly method would probably n o t b e adequa te as a

b l anch ing t echn ique .

This was n o t run s i n c e i t had been observed i n ea r l i e r t r i a l s

Under t h e s e c i r -

The BOD/N/P r a t i o f o r p o t a t o b l a n c h e r e f f l u e n t w a s 57/3.9/1 ( range

37-66/3.6-4.2/1) i n d i c a t i n g t h a t adeuqate n u t r i e n t s are available for

b i o l o g i c a l t r ea tmen t . The BOD/COD r a t i o averaged 0.90.

43

Objec t ive a n a l y s i s of t h e po ta to blanching t r ia l s i s summarized i n

Table 19 . The lower can vacuum f o r t h e steam blanched samples i s

a t t r i b u t e d t o o v e r f i l l r a t h e r than incomplete t i s s u e gas removal.

Table 19. SUMMARY OF OBJECTIVE EVALUATION OF POTATOESa

B 1 anc h ing t reatment

IQB-6.9

IQB Deep Bed

Control

(cm. Hg. vacuum) Months of S torage

1 3 6 9 Aver. Range Aver. Range Aver. Range Aver. Range

12.2 8.9-16.5 7.9 5.1-10.2 10.9 7.6-15.2 12.2 8.9-16.5

12.4 10.2-19.1 7.8 5.1-11.4 12.7 7.6-17.8 10.9 7.6-15.2 9.4 3.8-11.4 8.6 6.4-12.7 11.7 10.2-17.8 16.0 14.0-19.1

22.4 16.5-27.9 17.3 14.0-25.4 18.5 12.7-24.1 20.6 15.2-25.4

Table 20 presen t s a summary o f t h e s u b j e c t i v e eva lua t ions on pota toes .

The IQB predr ied b lanching technique w a s no t accep tab le due t o darkening

of t he po ta to s u r f a c e du r ing a i r d ry ing . This i s evidenced by the low

preference f o r t h e IQB-predried sample. With IQB and deep bed steam

IQB-6.9 334.6 332.2-335.0 330.6 326.1-333.8 338.2 331.4-342.9 343.6 335.0-352.9 330.9 320.7-335.7 336.3 328.8-340.4

Deep Bed 345.1 334.4-352.8 244.9 328.4-356.2 340.5 328.3-358.1 Control 312.4 285.7-335.4 286.6 274.2-301.3 311.3 292.6-350.8 A

44

333.1 328.6-336.8 336.0 325.3-343.9 337.4 330.4-343.7 308.4 283.1-357.1

Table 20. SUMMARY OF SUBJECTIVE EVALUATION OF POTATOES

B l a n c h i n g s t o r a g e t imeb

(months ) t r e a t m e n t a

IQB-6.9

1 3 6

5% 0.1% 1% 2-9-3 4-6-8 5-5-6

9

IQB-0

Deep bed

NS

NS NS NS

0.1% 4-9-3 NS NS

1% 4-8-5

1% 8-5-2

a IQB-6.9 means I Q B w i t h a 6.9% weight r e d u c t i o n p r i o r t o b l anch ing . IQB-0 means I Q B w i t h o u t p red ry ing . Deep bed means deep bed steam blanching .

Each sample was compared t o a c o n t r o l s ample . The c o n t r o l w a s canned t h e same day as t h e expe r imen ta l sample . The t o p number i s t h e l e v e l of s i g n i f i c a n c e and t h e bottom t h r e e numbers r e p r e s e n t number of judges p r e f e r r i n g expe r imen ta l sample, c o n t r o l and no p r e f e r e n c e , r e s p e c t i v e l y . NS means no s i g n i f i c a n t d i f f e r e n c e .

b

b l anch ing t h e r e w a s ve ry l i t t l e d i f f e r e n c e i n samples as evidenced

by t h e tas te pane l r e s u l t s .

pared i n l a r g e q u a n t i t y b a t c h e s ( f o r example, a can f u l l ) , t h e steam

blanched p roduc t appeared somewhat d a r k e r t han t h e p i p e b lanched .

This was b e l i e v e d due t o da rken ing of t h e p o t a t o e s i n t r a n s p o r t t o

t h e l a b o r a t o r y .

r e a d i l y a p p a r e n t s i n c e t h e taste pane l showed no p r e f e r e n c e .

However, when t h e p roduc t s were com-

The importance of t h i s s l i g h t da rken ing is n o t

I n c o n c l u s i o n , IQB wi thou t p red ry ing can be s u c c e s s f u l l y a p p l i e d t o

p o t a t o b l anch ing . A t t h e load ing rates used i n t h i s s t u d y , I Q B

o f f e r e d l i t t l e advantage ove r deep bed steam b lanch ing . However,

a t g r e a t e r l oad ing ra tes I Q B would be expected t o produce s i g -

n i f i c a n t l y less e f f l u e n t t h a n deep bed steam b lanch ing . The IQB

blanched product was e q u i v a l e n t t o c o n v e n t i o n a l l y canned product .

P red ry ing i s n o t recommended due t o s u r f a c e da rken ing d u r i n g a i r

d ehyd ra t ion. 45

BEET BLANCHING

The b e e t b l anch ing d a t a are summarized i n Table 21.

T o t a l E f f l u e n t o r g a n i c T o t a l Product

g e n e r a t i o n BOD5 n i t r o g e n phosphorus y i e l d (1. /kkg) (kg/kkg) ( kq /kkg ) (kg /kkg ) (%)

196 5.75 0.11 0.0285 86.3

229 4.95 0.085 0.022 89.4

225 4.8 0.11 0.0305 88.9

Table 21. SUMMARY OF BEET B U N C H I N G DATAa

S o l i d s l o s t as p roduc t

(%)

5.21

4.02

5.26

Blanching t r ea tmen tb

IQB-5.6

IQB-0

Deep bed

a Expressed complete d

1 l i

bIQB-5.6 means IQB w i t h a 5.6% weight r e d u c t i o n p r i o r t o b l anch ing . IQB-0 means I Q B w i t h o u t p red ry ing . Deep bed means deep bed steam b lanch ing .

A s w i t h p o t a t o e s s l i c e d b e e t s are n o t normal ly blanched p r i o r t o

canning and, t h e r e f o r e , t h e r e i s no c o n v e n t i o n a l b l anch ing o p e r a t i o n

f o r comparison. Gene ra l ly i t i s assumed t h a t b l anch ing w i l l be

accomplished i n t h e steam t r e a t m e n t a n d / o r h o t water p rocess j u s t

p r i o r t o p e e l i n g . F r e q u e n t l y , however, t h e c e n t e r t empera tu re of

t h e b e e t i s n o t i n t h e range t o i n a c t i v a t e enzymes. When t h i s i s

t h e c a s e , d e l a y i n g e t t i n g t h e s l i c e d o r d i ced b e e t s i n t h e can may

r e s u l t i n darkening of t h e b e e t , This i s u n d e s i r a b l e . The b e e t

s l ices t h a t were ob ta ined from t h e canning p l a n t f o r t h i s s t u d y had

p o s i t i v e pe rox idase a c t i v i t y p r i o r t o t h e steam b lanch ing r u n s .

The d a t a i n Table 21 reveal s e v e r a l impor tan t c h a r a c t e r i s t i c s of

b e e t b l anch ing . F i r s t , t h e e f f l u e n t g e n e r a t i o n v a l u e s are n e a r l y

t h e same as t h o s e r e p o r t e d f o r pea b l anch ing . The h i g h e f f l u e n t

g e n e r a t i o n v a l u e s , however, are t h e r e s u l t of c e l l u l a r l o s s e s r a t h e r

46

than i n a b i l i t y o f . t h e bee t su r f ace t o hold su r face moisture. The

BOD values a r e t h e h i g h e s t of those reported i n t h i s s tudy as are

the " so l id s l o s t as product" f i g u r e s . This i n d i c a t e s t h a t bee t

t i s sue i s very s u s c e p t i b l e t o h e a t damage.

of blanching w i l l r e s u l t i n high s o l i d s l o s s from the t i s s u e . For

comparison, Ralls e t a1.8 reported 317 l . / kg (76 g a l / t o n ) f o r steam

blanching of b e e t s and 5550 l . /kkg (1330 g a l / t o n ) f o r water blanch-

ing. Comparing IQB t o those r e s u l t s , IQB would reduce l i q u i d waste genera-

t i o n by about 28%. A s wi th green beans, t he 5550 l./kkg (1330 g a l /

ton) i s probably unduly l a rge s i n c e presumably more product could

have been run through the blancher , lowering t h e e f f l u e n t value.

Predrying t h e b e e t s u r f a c e p r i o r t o IQB r e s u l t e d i n a f u r t h e r d e -

c r ease i n e f f l u e n t generat ion; however, during a i r drying some

darkening d i d occur. This w a s undes i r ab le and r e s u l t e d i n a low

preference f o r t h a t t reatment .

Consequently, any method

The BOD/N/P r a t i o averaged 208/3.8/1 (range 158-292/3.6-4.0/1) i nd i -

c a t i n g t h a t bee t blancher water maybe low i n n i t rogen f o r b i o l o g i c a l

waste t reatment .

than t h e 0.87 reported by Soderquis t e t a l .

The BOD/COD r a t i o averaged 0.97 s l i g h t l y higher 10 .

Objective eva lua t ion of b e e t s r e s u l t e d i n t h e d a t a summarized i n

Table 22. The can vacuum was lower f o r a l l t h e steam blanched

samples compared t o c o n t r o l . Examination of the drained weight

d a t a shows t h a t t he experimental samples contained a t least 56 g.

(two ounces) more than t h e c o n t r o l and were o v e r f i l l e d . Instead of

using the 312 g. (11 ounce) f i l l weight, t h e f i l l weight could have

been 256 g. (9 ounces). The drained weight d a t a show t h a t i n t h e

can the bee t w i l l lose t i s s u e j u i c e s during t h e . r e t o r t i n g ope ra t ion

and consequently the drained weight i s less than t h e f i l l weight.

By blanching p r i o r t o canning t h e j u i c e is loSL before the bee t i s

p u t i n t h e can. From a canner 's point of view i t i s b e s t not t o

47

blanch p r i o r t o canning s i n c e then he has t o c l e a n up t h e b lancher

e f f l u e n t . Without b lanching , t h e e f f l u e n t ends up i n t h e can and

even tua l ly ends up i n t h e k i t c h e n where t h e housewife d i sposes of

i t . On the o t h e r hand, i f t h e canner has d i f f i c u l t y making dra ined

weight on canned b e e t s , then b lanching p r i o r t o canning w i l l a l low

him t o more n e a r l y match f i l l weight t o d r a i n weight.

Table 22. SUMMARY OF OBJECTIVE EVALUATION OF BEETSa

IQB-5.6

I Q B Deep Bed

Control

10.4 8.9-11.4 7.9 5.1-15.2 8.6 5.1-10.2 5.8 5.1-8.9 11.9 7.6-15.2 6.4 5.1-7.6 4.6 2.5-5.1 7.6 5.1-10.2 10.4 6.4-12.7 5.1 5.1-5.1 6.1 2.5-10.2 12.4 7.6-15.2 22.9 16.5-33.0 16.3 10.2-22.9 15.0 11.4-19.1 16.8 10.2-20.3

-~

Drained Weight (d

IQB-5.6

I Q B

Deep Bed

Control

330.3 327.2-331.4 329.7 326.6-330.8 329.2 327.6-330.8 332.8 329.8-334.9 327.5 323.4-332.3 325.7 320.3-328.2 332.3 328.3-338.0 329.4 323.1-337.8 326.3 323.8-327.0 329.2 320.8-332.7 336.3 328.3-340.0 332.8 325.1-339.1 265.5 249.7-281.0 262.1 240.5-279.0 250.2 218.0-266.5 259.6 244.1-288.5

48

Table 23. SUMMARY OF SUBJECTIVE EVALUATION OF BEETS

Blanching t rea tmenta

IQB-5.6

IQB

Deep bed

1 1%

4-7-4

NS

1% 6-6-4

S t o r a g e t i m e " (months )

NS

NS

NS

1% 3-7-4

NS

0.1% 2-15-1

0.1% 4-7-11

NS

NS

a IQB-5.6 means I Q B w i t h a 5.6% weight r e d u c t i o n p r i o r t o b l anch ing . IQB-0 means IQB wi thou t p red ry ing . Deep bed means deep bed steam b lanch ing .

Each sample w a s compared t o a c o n t r o l sample. The c o n t r o l w a s canned t h e same day as t h e expe r imen ta l sample. The t o p number i s t h e l e v e l of s i g n i f i c a n c e and t h e bot tom t h r e e numbers r e p r e s e n t number o f judges p r e f e r r i n g expe r imen ta l sample, c o n t r o l and no p r e f e r e n c e , r e s p e c t i v e l y . NS means no s i g n i f i c a n t d i f f e r e n c e .

b

I n c o n c l u s i o n , I Q B wi thou t p red ry ing i s a n e f f e c t i v e way of b lanch-

i n g b e e t s w i t h reduced e f f l u e n t g e n e r a t i o n . Beet t i s s u e i s ex t r eme ly

s e n s i t i v e t o h i g h t empera tu res r e s u l t i n g i n loss of t i s s u e j u i c e .

P red ry ing r educes e f f l u e n t f u r t h e r ; however, p roduct q u a l i t y i s ad-

v e r s e l y a f f e c t e d . Blanching p r i o r t o canning would b e an e f f e c t i v e

way t o i n s u r e meet ing d r a i n e d we igh t s f o r b e e t s .

CARROTS

C a r r o t b l anch ing d a t a are summarized i n Table 24. C a r r o t s , l i k e

o t h e r r o o t c r o p s , b e e t s and p o t a t o e s , are n o t normal ly blanched

a f t e r s l i c i n g o r d i c i n g u n l e s s t hey are t o b e f r o z e n o r dehydra ted .

The re fo re , t h e r e w a s no commercial b l anch ing o p e r a t i o n t o moni tor

i n t h i s s tudy . Even though t h e whole c a r r o t receives a h o t water

and steam t r e a t m e n t p r i o r t o p e e l i n g , pe rox idase a c t i v i t y w a s s t i l l

p r e s e n t i n t h e s l i c e d c a r r o t s . The v a l u e s i n Tab le 24 f o r e f f l u e n t

49

Table 24. SUMMARY OF CARROT B U N C H I N G DATAa

T o t a l E f f l u e n t o r g a n i c T o t a l

Blanching g e n e r a t i o n BOD5 n i t r o g e n phosphorus

IQB-0 192 2.0 0.10 0.016

Deep bed 225 2.6 0.14 0.023

t r ea tmen tb ( l . / kkg) (k- ( k g /kk g ) ( k g /kk g )

-

S o l i d s Product 10s t as y i e l d p roduc t

91.8 1.93

88.4 2.77

(%) (%)

gene ra t ed are similar t o t h e o t h e r s r e p o r t e d i n t h i s s tudy . Pre-

d r y i n g would be expec ted t o r educe b l a n c h e r e f f l u e n t even f u r t h e r .

I n t h e o r i g i n a l s t u d i e s by Lazar e t al .3 c a r r o t s p r e d r i e d t o a

5.8% weight r e d u c t i o n produced o n l y h a l f as much e f f l u e n t as IQB

w i t h o u t predry ing . The product y i e l d v a l u e s r e p o r t e d h e r e i n d i -

c a t e d t h a t t h e c a r r o t s u r f a c e l o s e s some of i t s moi s tu re -ho ld ing

c a p a c i t y a s t h e s u r f a c e t empera tu re i s i n c r e a s e d s i n c e t h e l o s s e s

are i n excess of t h o s e c a l c u l a t e d from s o l i d s l o s s . The BOD/N/P

r a t i o averaged 122/6 .3 /1 ( range 117-126/6.1-6.7/1) i n d i c a t i n g t h a t

c a r r o t b l a n c h e r e f f l u e n t h a s adequa te n u t r i e n t s f o r

b i o l o g i c a l waste t r ea tmen t . The BOD/COD r a t i o w a s 0.87.

Table 25 p r e s e n t s t h e r e s u l t s on t h e o b j e c t i v e e v a l u a t i o n of

c a r r o t s . There w a s no s i g n i f i c a n t d i f f e r e n c e i n e i t h e r t h e can

vacuum o r d r a i n e d we igh t s when steam blanched samples were compared

t o c o n t r o l samples.

S u b j e c t i v e e v a l u a t i o n r e s u l t s f o r c a r r o t s are shown i n Tab le 26.

The p r e f e r e n c e of t h e t as te pane l f o r t h e c o n t r o l sample i s markedly

e v i d e n t i n t h e s e d a t a . Th i s serves t o i l l u s t r a t e t h e importance of

50

Table 25 . SUMMARY OF OBJECTIVE EVALUATION OF CARROTS a

Blanching t rea tmentb

I Q B

Deep bed

Cont ro l

Months of S torage 1 3 6 9

Aver. Range Aver. Range Aver. Range Aver. Range

9 . 1 7.6-11.4 7.9 7.6-8.9 9 .9 5.1-16.5 1 3 . 7 12.7-15.2

11 .7 8.9-15.2 1 0 . 9 7.6-12.7 8 . 1 2.5-15.2 1 4 . 0 12.7-15.2

9 . 1 7.6-11.4 7 . 1 3.8-8.9 7.9 2.5-12.7 1 0 . 9 10.2-12.7

I Q B 284.0 280.1-285.5

293.9 291.1-295.4 Deep bed

286.6 284.0-288.8 284.3 281.4-287.9 283 .1 278.1-286.6

292.5 290.7-293.4 290.5 285.9-293.2 293.7 291.5-295.2

267.5 259.4-274.7 265.5 262.5-277.7 280.6 272.4-292.2 278 .3 273.0-284.8

a Each average cons i s t ed of t h r e e obse rva t ions .

Cont ro l samples were n o t blanched p r i o r t o canning. The whole c a r r o t was t r e a t e d i n h o t water and steam be fo re pee l ing .

IQ B

Deep bed

Table 2 6 . SUMMARY OF SUBJECTIVE EVALUATION OF CARROTS

0-11-5 6-13-7 , 5-12-3 1-9-10

0.1% 0.1% 0.1% 0.1% 2-11-7 5-10-6 4-11-5 2-8-10

Sto rage timeb Blanching I (months ) treatment" I 1 3 6 9

0.1% I 0.1% I 0.1% I 0.1%

51

c o l o r i n product e v a l u a t i o n . The steam blanched c a r r o t s were t r a n s -

po r t ed t o t h e l a b o r a t o r y and t h e r e w a s c o n s i d e r a b l e da rken ing of t h e

t i s s u e even though i t w a s h e l d under water. The taste pane l p r e f e r r e d

t h e b r i g h t e r orange c o l o r of t h e c o n t r o l . I n t h e s t u d y by Lazar e t

a l .3 IQB samples were judged t o be b e t t e r t h a n t h e c o n v e n t i o n a l l y

steam blanched p roduc t . I n t h e o p i n i o n of most of t h e judges t h e o n l y

d i f f e r e n c e between samples i n t h e p r e s e n t s t u d y w a s c o l o r .

I n c o n c l u s i o n , IQB can be used t o b l anch c a r r o t s p r i o r t o cann ing ,

f r e e z i n g o r dehydra t ion . There w a s no a d v e r s e e f f e c t s of t h e steam

b lanch ing t r e a t m e n t on c a r r o t s p r i o r t o canning . Blanching of c a r r o t s

p r i o r t o canning could be recommended i f t h e r e are unduly long d e l a y s

between c u t t i n g and can f i l l i n g . During t h i s d e l a y c o l o r changes

could occur .

LOADING RATE AND SIZE OF COMMERCIAL IQB UNITS

One of t h e b a s i c p r i n c i p l e s i n h e r e n t in . IQB i s t h a t each piece of

v e g e t a b l e r e c e i v e s t h e same thermal energy as eve ry o t h e r p i e c e . I f

t h e r e i s some c o n d i t i o n which a l t e r s exposure t ime o r ra te of h e a t

t r a n s f e r t o t h e s u r f a c e of t h e v e g e t a b l e , t h e n t h e r e i s t h e p o s s i -

b i l i t y of underb lanching . I n h e a t t r a n s f e r t h e t o t a l q u a n t i t y of

h e a t t r a n s f e r r e d i s d i r e c t l y p r o p o r t i o n a l t o t h e exposed s u r f a c e

area. Loading c o n d i t i o n s which w i l l d e c r e a s e t o t a l s u r f a c e exposed

may r e s u l t i n unde rp rocess ing and t h e r e f o r e b e l t l o a d i n g ra te i s an

ex t remely impor tan t v a r i a b l e i n t h e IQB p rocess .

The b e l t l oad ing rates f o r t h e h e a t b e l t , ho ld b e l t and deep bed

steam h e a t i n g b e l t were c a l c u l a t e d based on through-put , r e s i d e n c e

time and b e l t dimensions. The r e s u l t s f o r each run are g iven i n

t h e Appendix.

52

To summarize t h e d a t a , t h e f o l l o w i n g o b s e r v a t i o n s can be made: 1 )

Heat b e l t l oad ing- - fo r t h e I Q B p rocess t h e h e a t b e l t w a s loaded a t

approximate ly 4.9 kg/m

be op t ima l l oad ing f o r expos ing each p i e c e t o t h e steam c o n d i t i o n s

i n t h e h e a t s e c t i o n . This load ing w a s recommended i n p rev ious p u b l i -

c a t i o n s on IQB ,

what h i g h e r , g e n e r a l l y 6.3 t o 9.8 kg/m (1.3 t o 2.0 l b . / f t ). With

t h e s e two p roduc t s h i g h e r p roduc t l oad ing rates could be used s i n c e

medium s l i c e s (3.2-4.4 cm. d i ame te r by 0.64 cm. t h i c k ) d i d n o t pack

and reduce h e a t t r a n s f e r s u r f a c e area a s much as o t h e r product forms

(i.e. peas, c o r n , lima beans , o r g reen beans ) . With d e e p bed b lanch-

i n g , l oad ing ra te w a s l i m i t e d by c o n f i g u r a t i o n of t h e equipment. The

deep bed w a s 5.1 t o 6.4 cm. (2 t o 2.5 i n c h e s ) d e e p r e s u l t i n g i n d i f - 2 f e r e n t l oad ing ra tes depending on p roduc t geometry: peas--12.9 kg/m

2 2 1 (1 l b . / f t ). For t h e s e p roduc t s t h i s would

For b e e t s and c a r r o t s , b e l t l oad ings were some- 3 2 2

2 2 2 2

2 2 (2.65 l b / f t ) ; corn--14.5 kg/m

(3.04 l b / f t ); green beans--7.03 kg/m2 (1.44 l b / f t ) ; p o t a t o e s - - 2 2 2 2 11.8 kg/m (2.41 l b / f t ); beets--16.4 kg/m (3.36 l b / f t ) and c a r r o t s - - 2 2 16.0 kg/m

(2.98 l b / f t ) ; lima beans--14.8 kg/m

(3.28 l b / f t ). Green beans had t h e lowest product d e n s i t y

i n t h e deep bed. This would be expec ted s i n c e c y l i n d e r s w i t h a

l e n g t h t o d i ame te r r a t i o of 3 : l have a v e r y low packing d e n s i t y .

Hold b e l t l o a d i n g s - - i n t h e IQB p rocess hold b e l t l oad ings v a r i e d

2 )

2 2 2 - 2 from 17.6 kg/m (3.6 l b / f t ) f o r p o t a t o e s t o 69.3 kg/m (14.2 l b / f t )

f o r green beans. Hold s e c t i o n b e l t l oad ing r e f l e c t s t h e compounding

e f f e c t of many v a r i a b l e s i n c l u d i n g r a t i o of h e a t r e s i d e n c e time t o

hold r e s i d e n c e t i m e , r a t i o of h e a t b e l t wid th t o ho ld b e l t w i d t h ,

and r a t i o of h e a t s e c t i o n l e n g t h t o ho ld s e c t i o n l e n g t h . For ou r

system t h e h e a t and hold b e l t s were n e a r l y t h e same wid th [21.6 cm

(8.5 i n c h ) wide h e a t b e l t ; 20.3 cm (8.0 inch ) wide hold b e l t ] and

t h e l e n g t h r a t i o was 3/1 [ i .e . 91.4 cm ( 3 f t ) h e a t s e c t i o n / 3 0 . 5 cm

(1 f t ) ho ld s e c t i o n ] . The r a t i o of h e a t b e l t l oad ing t o hold b e l t

l oad ing shou ld , under t h e s e c o n d i t i o n s , be e q u a l t o t h e r a t i o of t h e

l i n e a l v e l o c i t y of t h e hold b e l t t o t h e l i n e a l v e l o c i t y of t h e h e a t

b e l t .

53

l i n e a l v e l o c i t y ho ld b e l t l i n e a l v e l o c i t y h e a t b e l t

l oad ing ra te h e a t b e l t l oad ing ra te ho ld b e l t

The l i n e a l v e l o c i t y i s t h e l e n g t h of t h e b e l t d i v i d e d by t h e resi-

dence time i n t h e s e c t i o n and s i n c e L(Heat)/L(Hold) = 3/1, t h e load-

i n g r a t e on t h e h e a t b e l t / l o a d i n g ra te on t h e hold b e l t i s :

r e s i d e n c e t i m e i n h e a t s e c t i o n r e s i d e n c e time i n ho ld s e c t i o n

(Loading r a t e )

(Loading rate)Hold

o r

where L.R. = l oad ing r a t e , kg/m 2

and 7. = r e s i d e n c e t i m e , seconds .

Using h e a t h o l d times r e p o r t e d i n t h i s s t u d y , t h e s ize of a comer-

c i a 1 b e l t - t y p e IQB u n i t was c a l c u l a t e d and is g iven i n Table 27. A 2 2

h e a t b e l t l oad ing ra te of 4.9 kg/m (1 l b / f t ) and a hold b e l t

l oad ing ra te of 49 kg/m

t h e same as t h o s e r e p o r t e d i n Table 3. For comnerc ia l u n i t s i t

would be expec ted t h a t c o s t s f o r a n IQB b l a n c h e r of t h i s c o n f i g u r a -

t i o n would n o t be more t h a n t h a t f o r r o t a r y - t y p e water b l a n c h e r s of

comparable p roduc t ion c a p a c i t y . Compared t o c o n v e n t i o n a l steam b l a n c h e r s , IQB would be less c o s t l y s i n c e t h e IQB u n i t is c o n s i d e r -

a b l y s h o r t e r f o r t h e same produc t ion c a p a c i t y .

2 2 (10 l b / f t ) was assumed. Blanch times are

Regarding developments of hardware f o r I Q B u n i t s , t h e e n g i n e e r i n g

r e s e a r c h team a t Western Regional Research Labora to ry , USDA,

Berke ley , r e c e n t l y r e p o r t e d ” on t h e development of a p r o t o t y p e

I Q B u n i t u s i n g s p i r a l v i b r a t i n g conveyors. High p roduc t ion rates,

compactness, s i m p l i c i t y and c o n t r o l of r e s i d e n c e t ime were claimed

54

f o r t h e u n i t . A l a r g e r p ro to type is planned f o r cons t ruc t ion .

Prodbc t

Peas

Corn

Lima beans

Green beans

Po t a t oes

Car ro t s

Beets

Table 27. ESTIMATED I Q B PRODUCTION UNITSa

(kkg product /hr )

9.1

13.6

13.6

13.6

4.5

5.7

5.7

I

Product ion r a t e

( tons p r o d u c t / h r l

10

15

15

15

5

6.3

6.3

a Heat 1.52m (5 f t ) wide x 9.14 m (30 f t ) long loaded a t 4.9 kg/m2 (1 l b / f t 2 ) .

Hold 1, 2 m (5 f t ) wide x 1.37 m (4.5 f t ) long loaded a t 49 kg/m 1 (10 l b / f t 2 ) .

55

SECTION V I 1

UNITS FOR INTERCONVERSION OF DATA

To a i d i n the i n t e r c o n v e r s i o n and i n c r e a s e d d i g e s t i b i l i t y of d a t a con-

t a i n e d i n this r e p o r t , several impor t an t conve r s ion f a c t o r s are p re -

s en ted i n t h e f o l l o w i n g t a b l e :

Tab le 28. FACTORS FOR INTERCONVERSION OF DATA

I To c o n v e r t from:

cm

g

kkg

kg /m2

cm

1. /kkg

kg/kkg

1. / h r

1. /case

To : I M u l t i p l y by:

f t .

ounces

t o n

l b / f t2

i n .

g a l / t o n

l b l t o n

ga 1 / h r

ga l /case

0.0328

0.0353

1.103

0.205

0.394

0.240

2.00

0.264

0.264

A l l of the v a l u e s con ta ined i n t h i s r e p o r t based on t h e amount o f

product were c a l c u l a t e d based on t h e amount of p roduc t (kkg o r t on )

processed. It i s f r e q u e n t l y d e s i r a b l e to know e f f l u e n t g e n e r a t i o n

based on p l a n t i n p u t rather t h a n p l a n t o u t p u t . T h e r e f o r e , t o f a c i l i -

t a t e these c a l c u l a t i o n s the f o l l o w i n g are g iven :

56

Table 29. CANNING YIELD FACTORS

Ton r a w product a b Pounds product Cases Product case t o n r a w product t on processed p roduc t

Peas 15.5 115 1.13

Corn 15.75 32 3.97

Lima beans 13.5 130 1.14

Green beans 13.5 125 1.19

Po ta toes 16.5 75 1.62

Beets 16.5 70 1.73

C a r r o t s 14.6 65 2.10

a

b Calcu la ted based on f i l l weight .

Reference 12.

57

SECTION V I 1 1

REFERENCES

1. Weckel, K. G . , R. S. Rambo, H. Veloso, and 3. H. von Elbe . Vegetab le

Canning Process Wastes. R e s . R p t . No. 38. Col lege of A g r i c u l t u r a l

and L i f e S c i e n c e s , Univ. Wisconsin-Madison, p. 1-20, 1968.

2. Na t iona l Canners A s s o c i a t i o n . R e s . I n fo rma t ion B u l l . No. 170 ,

January 1971.

3 . Lazar , M. E . , D. €3. Lund and W. C. D i e t r i c h . IQB: A New Concept i n

Blanching. Food Tech. 25:684-686, J u l y 1971.

4 . Lund, D. B . , S. L. Bru in , Jr . , and M. E. Lazar . I n t e r n a l Temperature

D i s t r i b u t i o n During I n d i v i d u a l Quick Blanch. J. Food S c i . 37:183,

January 1972.

5. Lund, D. B. A F i e l d Study on t h e A p p l i c a t i o n of I n d i v i d u a l Quick

Blanch. I n : Proceedings Thi rd Na t iona l Symposium on Food P rocess ing

Wastes. Washington, D. C . , U. S. Government P r i n t i n g Of f i ce . EPA-

R2-72-018, 1972.

6. S tandard Methods f o r t h e Examination of Water and Waste Water. 1 3 t h

ed. New York, A m e r . Publ. Hea l th ASSOC., I nc . , 1790 Broadway, 1971.

7. Van Buren, J. P., J. C. Moyer, D. E. Wilson, W. C. Robinson, and

D. B . Hand. I n f l u e n c e of Blanching Cond i t ions on S loughing , S p l i t t i n g

and Firmness of Canned Snap Beans. Food Tech. 14:233, 1960.

8. Ra l l s , J. W . , H. J. Maagdenberg, N. L. Yacoub, and W . A . Mercer.

Reduced Waste Genera t ion by A l t e r n a t e Vegetab le Blanching Systems.

I n : Proceedings Thi rd Na t iona l Symposium on Food P rocess ing Wastes.

Washington, D. C . , U. S. Government P r i n t i n g O f f i c e . EPA-R2-72-018,

1972. p. 25-70.

58

REFERENCES (cont inued)

9. Lee, F. A . The Blanching Process. I n : Advances i n Food Research.

Vol. 8. New York, Academic P res s . , 1958. p. 63.

10. Soderqu s t , M. R. , G. I. Blanton and D. W. Taylor . C h a r a c t e r i z a t i o n

of F r u i t and Vegetable Process ing Waste Waters. In : Proceedings

Third Na t iona l Symposium on Food Process ing Wastes.

D. C. , U. S. Government P r i n t i n g O f f i c e . EPA-R2-72-018, 1972.

Washington,

p. 409-436.

11. Brown, G. E. Pe r sona l Communication and paper p re sen ted a t the

Annual Meeting I n s t i t u t e of Food Techno log i s t s , M i a m i Beach,

June 1973.

12. . 1971-1972 Yearbook. Canner Packer. 140:9, 1971. p. 102.

59

SECTION IX

LIST OF PUBLICATIONS

1, Lund, D. B. The I n d i v i d u a l Quick Blanching Process . Michigan S ta t e

Un ive r s i ty . H i g h l i g h t s i n Food S c i e n c e , March 1973.

2 . Lund, D. B. Impact of t h e I n d i v i d u a l Quick Blanch (IQB) Process on

Cannery Waste Genera t ion . P resen ted a t t h e Four th Na t iona l Sym-

posium on Food P rocess ing Wastes, Syracuse , New York, A p r i l 1973.

3 . Lenz, M. K. and D. B. Lund. L e t h a l i t y C a l c u l a t i o n s f o r Heat/Cool

P rocesses by t h e L-Fo Method. Submit ted t o J. Food S c i e n c e , 1973.

60

A 1

A2

A 3

A4

A5

A6

A7

A8

A9

A10

A l l

A 1 2

A 1 3

A14

S e c t i o n X

Appendix - Raw Data

I n d i v i d u a l Blanching Trials f o r Peas

C h a r a c t e r i s t i c s of E f f l u e n t s Generated During Pea Blanching

I n d i v i d u a l Blanching Trials f o r Corn

C h a r a c t e r i s t i c s of E f f l u e n t s Generated During Corn Blanching

I n d i v i d u a l Blanching Tr ia l s f o r L ima Beans

C h a r a c t e r i s t i c s of E f f l u e n t s Generated During L i m a Bean Blanching

I n d i v i d u a l Blanching Trials f o r Green Beans

C h a r a c t e r i s t i c s of E f f l u e n t s Generated During Green Bean Blanching

I n d i v i d u a l Blanching Trials f o r P o t a t o e s

C h a r a c t e r i s t i c s of E f f l u e n t s Generated During P o t a t o Blanching

I n d i v i d u a l Blanching Trials f o r Beets

C h a r a c t e r i s t i c s of E f f l u e n t s Generated During Beet Blanching

I n d i v i d u a l Blanching Trials f o r C a r r o t s

C h a r a c t e r i s t i c s of E f f l u e n t s Generated During C a r r o t Blanching

Page

62

63

65

66

68

69

7 1

72

73

74

75

76

77

78

61

Table A l . INDIVIDUAL BLANCHING TRIALS FOR PEAS

R lanchinga t rea tment

IQB- 6 . 25-4-Als

IQB-0-4-Als

30 Sec-4-Als

Deep bed-4- A l s

IQB- 7.0- 3-Ala

IQB- 0- 3-Ala

30 Sec-3-Ala

Deep bed- 3- A l a

IQB- 7.5- Perf .

IQB-O- P e r f ,

30 Sec-Perf.

Deep bed- Perf . Averages

IQB-6.9

IQB- 0

30 Sec

Deep bed

- Treat- men t number

1 P

2P

3P

4P

5P

6 P

7P

8P

9 P

10P

11P

1 2 P

- Bel t Hea5

(kp;/m ; 5.08

5.42

5.42

13 . 13

4.49

4.39

4.20

13.52

5.42

5.86

5.22

12.20

-

5.00

5.22

4.93

12.93

- ,ad in8

Ho 11 (kg/m )

24.20

25.82 -- I-

21.52

20 . 94 -- --

25.91

28.01 -- --

23.86

24.94 -- --

- E f f l u e n t

gene ra t i o n ( l . / c a s e )

1.09

1.76

1.51

2.15

0.913

1.47

1.39

2.15

1.10

1.51

1.51

2.29

1.04

1.58

1.47

2.19

- 'roduc t y i e l d

(%)

88.8

87.5

90.0

83.8

90.0

90.5

91.3

83.8

87.5

90.0

90 .o 82.5

88.8

89.3

90.4

83.3

__ Solids l o s t as product

(%)

1.37

1.57

2.10

3.31

1.14

2.51

1.85

2.77

2.10

2.12

2.33

3.26

1.53

2.07

2.09

3.11

IQB-6.25 means IQB wi th a 6.25% weight r educ t ion p r i o r t o blanching. IQB-0 means IQB wi thout predrying. 30 s e c means h e a t on ly s t a g e of IQB. Deep bed means deep bed steam blanching. 4 o r 3 r e f e r s t o s i e v e s i z e ; p e r f e c t i o n w a s s i e v e s i z e 3 , 4 and 5. A l s means Alsweet; A l a means Alaskan; Perf . means P e r f e c t i o n .

a

62

Table A2. CHARACTERISTICS OF EFFLUENTS GENERATED DURING PEA BLANCHING

a Treatment number

1 P

2 P

3P

4P

5P

6P

7P

8 P

9P

10P

11P

12 P

Pipe

Pipe

Ave rag es

IQB-6 . 9

IQB- 0

30 Sec

Deep bed

Pipe

9 730

7260

11300

13200

10300

15800

10500

13400

15600

11400

13600

14200

8 300

7500

11900

11500

11800

13600

7900

T o t a l s o l i d s

(%)

1.99

1.43

2.16

2.58

1.94

2.66

2.04

2.16

3.06

2.18

2.40

2.44

1.54

1.42

2.33

2.09

2.20

2.39

1.48

T o t a l phosphorus

82

77

107

113

164

2 15

167

174

195

154

162

189

150

105

( P P 4

14 7

149

145

159

128

T o t a l o rgan ic n i t r o g e n

4 14

294

48 5

596

548

768

6 12

6 78

893

6 84

74 7

824

46 3

433

(PPm)

6 18

582

6 15

699

448

63

Treatment number

1 P

2P

3P

4P

5P

6P

7P

8P

9P

10P

11P

12P

Pipe

Pipe

Averages

IQB- 6 .9

IQB- 0

30 Sec

Deep bed

Pipe

Table A2 (cont inued) .

Jo la t i 1 e s o l i d s ( P P d 18000

13000

19600

23500

17300

23400

18200

19200

27100

19200

2 1200

2 1600

13400

12200

20800

18500

19 700

2 1400

12800

FLUENTS C juspendec vo l a t i 1c

s o l i d s ( P P d 644

476

595

58 1

329

547

473

389

2170

1120

1230

99 1

200

775

1050

7 13

765

654

488

JERATED C

Suspended s o l i d s

(%I .066

.055

.069

.070

034

.058

.052

.050

.224

.119

.132

. lo8

.025

.087

. lo8

.077

.084

.076

. 056

CHARACTERISTICS OF ZING PEA E

So lub l e phos pho rus

37

30

46

55

75

113

102

99

10 1

84

94

9 1

77

52

(ppm>

7 1

76

8 1

82

65

ANCHI N - - m3 - ( P P d

20

15

19

27

24

28

16

22

37

32

32

37

25

36

27

25

23

29

31 -

:rage

N03 NO2 : P P d _I

1.0

0.7

0.6

0.6

0.9

0.8

0.6

0.6

0.6

0.7

0.6

1 .o 0.6

0.9

0.8

0.7

0.6

0.7

0.8 -

See f o o t n o t e and t rea tment number on Table A l . b lanching.

P ipe means p ipe a

-

PH 7 .O

7 .O 7 .O 7.0

6.6

6.9

6.9

6.9

5.8

7 .O 5.9

5.9

7.7

7.3

6.8

7 .O 6.9

6.9

7.5 _I

No va lue i n d i c a t e s too s m a l l t o be measured.

64

Table A3. INDIVIDUAL BLAFCHING T R I A I S FOR CORN

Blanchinga t rea tment

IQB- 7.5

IQB- 0

20 Sec

Deep bed

IQB-7.5

IQB- 0

20 Sec

Deep bed

IQB-7.5

IQB- 0

20 Sec

Deep bed

Aver ag es

IQB- 7.5

IQB- 0

20 Sec

Deep bed

Trea tmen. number

1c 2c

3c

4 c

5c

6C

7c

8C

9c

1oc 11c

12c

- - B e l t Heat kg /m2

4.73

4.39

4.39

2.40

5.66

3.81

4.39

6.40

6.30

5.12

5.12

4.84

_I

5.56

4.44

4.64

4.54 -

)ad ing Ho 19

Lkg/m 1 22.59

20.94 -- --

27.08

18.30 -- --

30.11

24.40 -- --

26.60

21.23 -- --

E f f l u e n t :enera t ion

( l . / c a s e )

.489

.978

.822

1.17

.644

.921

1 .oo 1.20

.728

.819

.826

1.11

6.22

.906

.883

1.16

Product y i e l d

(%)

94.7

96.3

98.1

94.1

92.8

96.9

95.9

93.8

91.9

98.1

98.1

94.9

93.1

97.1

97.4

94.2

s o l i d s l o s t i s product

.50

1.43

1.00

1.90

1.14

1.75

1.87

3.19

.79

1.66

1.68

2.17

(%)

.81

1.61

1.52

2.42

a IQB-7.5 means I Q B with 7.5% weight r educ t ion p r i o r to blanching. IQB-0 means IQB wi thout predry ing . 20 s e c means h e a t on ly s t a g e o f IQB. Deep bed means deep bed steam blanching.

65

Table A4. CHARACTERISTICS OF EFFLUENTS GENERATED DURING CORN BLANCHING

a Treatment number

1c 2c

3c

4c

5c

6C

7c

8 C 9c

1oc 11c

12c

Pipe

Pipe

Pipe

Averages

IQB- 7.5

IQB- 0

20 See

Deep bed

Pipe

BOD5

10400

14000

12500

16600

24900

22700

28300

37800

13800

26500

3 1000

26800

3000

6500

11000

( P P d

16400

2 1000

23900

2 7000

6800

COD ( P P d

-- -- -- --

29900

32400

33400

51900

23300

34200

34500

30 700 -- -- --

26600

3 3 300

34000

4 1300 --

T o t a l s o l i d s

(% 1 1.94

2 .71

2.23

3.10

3.38

3.50

3.48

5.09

2.13

3.68

3.72

3.69

.455

.884

1.61

2.48

3.30

3.14

3.96

,983

To ta l phosphorus

104

159

135

170

105

132

14 2

189

87

172

16 9

154

30

40

72

(ppm)

99

154

149

1 7 1

47

T o t a l o rgan ic n i t rogen

(PPm) 177

296

231

260

211

255

2 56

322

196

368

398

3 18

68

100

208

195

306

295

300

125

66

E

V o l a t i l e Treatment s o l i d s

numb e r ( Ppm) 1c 2c

3c

4c

5c

6C

7c

8C

9c

1oc 11c 12c

Pipe

Pipe

Pipe

Averages

IQB- 7.5

IQB- 0

20 Sec

Deep bed

Pipe

18300

25600

20900

29 100

32400

33500

33300

48900

20500

35300

35900

34200

3970

8250

15200

23700

3 1500

30000

3 7400

9 140

Table A4 (cont inued) . FLUENTS C juspendec vo l a t i l c

s o l i d s ( P P d 1240

1700

3010

7 12

1780

6390

8660

246 0

1360

13400

4710

2060

2 15

46 0

1120

1460

7170

5460

1750

600

NERATED L

Suspended s o l i d s

f%)

.136

.179

.307

,076

.187

.639

.880

.247

.136

( 1.344)

.471

.206

.022

.047

.112

.153

.409'

.553

.176

.060

CHARACTERISTICS OF RING CORN

Soluble pho s pho rus

( P P d 50

89

86

98

101

106

114

151

17

38

37

24

15

30

18

56

78

79

91

2 1

LANCHING - 1 -

m3 ")

7

5

4

8

22

13

13

25

11

14

13

16

2

7

7

13

11

10

17

5 -

:rage -q N02 0

-

- c

NO2 0 --

-- -- --

.02

.03

.03

rrace

Inter

:nter

Inter

h t e r --

. l o :n t e r

.02

.03

.03

' race

.10 -

pH 6.5

6.4

6.8

6.8

7.0

7 .O

6.9

6.9

7.0

6.9

7.0

7.2 7.5

7.9

6.9

6.8

6.8

6.9

7.0

7.4 -

a See f o o t n o t e and t rea tment number on Table A3.

I n t e r f e r e n c e on a l l NO3-N de te rmina t ions .

The 1.344 v a l u e w a s n o t used i n t h e average s i n c e i t was h igher than corresponding va lues by f a c t o r of 10.

No va lue means too s m a l l t o be measured. I n t e r means i n t e r f e r e n c e .

C

67

Table AS. INDIVIDUAL BLANCHING TRIALS FOR LIMA BEANS

a B 1 an ch i ng t rea tment

IQB-5 .O

IQB- 0

20 Sec

Deep bed

IQB- 0

20 Sec

Deep bed

Averages

IQB- 5

IQB- 0

20 Sec

Deep bed

reatment number

1LJ3

2LB

3LB

4LB

5LB

6 LB

7 LB

Be l t '

Heat kg /m2)

4.83

5.76

6.10

15.32

4.39

5.12

14.35

4.83

5.08

5.61

14.84

)ad ing Ho I d

Ikg /m2 )

61.78

73.15 -- --

55.79 -- --

61.78

64.46 -- --

E f f l u e n t gene ra t ion

( 1 . / case)

.406

.879 . 750

1.00

1.22

.860

1.91

.406

1.05

.807

1.46

Product y i e l d

(%I 97.5

95.6

97.5

94.1

91.3

95.9

83.4

97.5

93.4

96.7

88.7

lo l id s l o s t is product

(%)

.24

.63

.34

.84

1.10

. 75

1.93

.24

.86

.54

1.38

a IQB-5.0 means IQB wi th a 5.0% weight r educ t ion p r i o r t o blanching. IQB-0 means IQB wi thout predrying. 20 s e c means h e a t only s t a g e of IQB. Deep bed means deep bed s t e a m blanching.

68

a Treatment number

1 LB

2 LB

3 LB

4 LB

5 LB

6LB

7 LB

P ipe

P ipe

P i p e

P ipe

Averages

IQB-5 .O

IQB- 0

20 Sec

Deep bed

Pipe

Table A6. CHARACTERISTICS OF EFFLUENTS GENERATED DURING LIMA BEAN BLANCHING

BOD ( P P d 5220

6170

5810

12800

13700

29900

16 300

1200

7 70

400

400

5220

9930

17800

14500

693

COD (PPm) 7790

11900

6750

13800

17600

12800

21200 -- -- -- --

7790

14800

9780

17500 --

T o t a l s o l i d s

(%)

1.20

1.48

0.91

1.77

1.96

1.80

2.42

.20

.13

.10

.10

1.20

1.72

1.36

2.10

.13

To ta l phosphorus

(PPm) 53

7 1

47

100

160

146

225

38

8

6

6

53

116

97

163

15

To ta l organic. n i t r o g e n

( P P d 34 1

557

3 18

495

864

560

8 79

42

26

27

28

34 1

711

439

687

31

69

Table A6 ( con t inued) . CHARACTERISTICS OF EFFLU

Vo l a t i l e Treatment solids

number ( P P 4

1LB

2LB

3L4B

4 LB

5 LB

6 LB

7 LB

P ipe

P i p e

P i p e

P ipe

Averages

IQB- 5 0

IQB-O

20 Sec

Deep bed

Pipe

9830

12300

74 70

14500

14100

15200

19600

1390

850

625

660

9830

13200

11400

17000

881

!ITS GENER jus pend ed vo la t i le

s o l i d s ( P P d

606

2320

1370

2250

2520

1660

2650

125

65

25

30

606

2420

1520

2450

61

PED DURIK

Suspended s o l i d s (70) .060

.240

.154

.228

.263

.182

.282

.014

.010

.004

.005

.060

.252 . 168

,255

.008

a See f o o t n o t e and treatment number on P i p e r e f e r s t o p i p e b l anch ing ,

I n t e r means i n t e r f e r e n c e .

LIMA BEAN

So lub le phosphorus

35

40

27

43

9

8

10

13

2

1

1

( P P 4

35

25

18

26

4

Ilable A5.

3LANCHING - NH3

( P P d

6

9

7

16

20

17

1 3

2

1

2

1

6

15

12

14

2 -

9 N03 N02

( P P 4

4.5

4.1

3.2

3.1

I n t e r

I n t e r

I n t e r

2.7

2.5

I n t e r

I n t e r

-

4.5

4.1

3.2

3.1

2.6 -

- b

NO2 Ppm)

. 07

. 05

.OS

.02

:n t er

:n t er

: n t e r

. 02

.02

Inter

: n t e r

-

. 07 . 05

.05 . 02

. 02 -

-

PH

6.8

6.7

6.8

6.4 6.5

6.6

6.5

8.5

8.6

7.9

7.6

-

6.8

6.6

6.7

6.5

8.2 -

70

Table A7. INDIVIDUAL BLANCHING TRIALS FOR GREEN BEANS

~~~ ~~

a Blanching t r e a t m e n t

IQB- 0

Deep bed

IQB-0,

IQB- C

h e a tment number

1GB

2GB

3GB

4GB

- Belt Heat, kg /m'

6.78

7.42

4.39

5.12

6.73

6.88

_I_

5.42

7.03

Averages

IQB- 0

Deep bed

oad i n g Ho Id

(kg /m2 > 86.72

-- 55.78

65.05

-- --

69.20 --

E f f l u e n t g e n e r a t i o n

(l./case>

1 mi30

1.10

.841

.883

.618

.603

1.01

. 773

a IQB-0 means IQB w i t h o u t p red ry ing . Deep bed means deep bed steam blanching .

'r odu c t y i e l d

(% > 90.0

92.8

96.3

95.6

99.4

99.7

94.0

97.3

S o l i d s l o s t as product

(%> --

2.09

1.88

.45

.34

.23

1.16

.89

71

Table A8. CHARACTERISTICS OF EFFLUENTS GENERATED DURING GREEN BEAN BLANCHING

~~ ~

a Treatment number

1GB

2GB

3GB

4GB

5GB

6GB

Ai erages

IQB- 0

Deep bed

a Trea t men t numb e r

1 G B

2GB

3GB

4GB

5GB

6GB

Averages

IQB- 0

Deep bed

BOD ( P P d

5890

9320

10100

2230

2560

1790

6070

4560

o l a t i l e s o l i d s

(PPm) --

10700

12000

2 700

2850

1980

7350

5190

COD (PPm) 29 10

6530 -- -- -- --

2910

6530

jus pend ed vo l a t i 1 e

so l i d s (PPm)

-- 19 1

1010

26 1

99

119

6 36

136

T o t a l s o l i d s

(a) --

1.26

1.43

.324

.341

.235

.877

.612

~ ~~

;us pended s o l i d s

(%) --

.026

.123

.036

.013

.016

.080

.018

To ta l phosphorus

53

72

8 2

2 1

24

17

(PPm)

52

38

So lub l e phosphorus

(PW) 36

42

4 11

1

1

17

15

N

ITH3 (PPm) 11

5

27

2

2

2

14

3

troge

No 3 N02 (PPm)

T o t a l o rgan ic n i t r o g e n

149

235

2 70

156

64

53

(PPm)

192

117

b

N02 (PPm) PH

7.9

6.5

5.3

5.2

5.1

5.5

-

6.1

5.7

a See foo tno te and t rea tment number on Table A7. NO /NO and NO were n o t determined. 3 2 2

72

Table A9. I N D I V I D U A L BLANCHING TRIALS FOR POTATOES

umber

lPOT

2POT

3POT

4POT

5POT

Blanchinga Treatment F= Heat,, (kg/m’j

3.56

5.76

11.76

5.76

5.08

3.56

5.51

11.76

t r ea tmen t

IQB-6.9

IQB- 0

Deep bed

IQB - 0

IQB- 0

Averages

IQB- 6 .9

IQB- 0

Deep bed

oad i n g Ho I d

(kg /m2

17.03

18.30 --

18.30

16.10

17.03

17.57

--

E f f l u e n t g en e r a t i o n (1. / case )

.754

1.31

1.25

1.40

.868

.754

1.20

1.25

Product y i e l d

(%>

93.1

93.1

93.8

92.2

95 .O

93.1

93.4

93.8

S o l i d s l o s t a s product

.43

.60

.78

.60

.61

(%)

.43

.60

.78

a IQB-6.9 means IQB w i t h a 6.9% weight r e d u c t i o n p r i o r t o b l anch ing , IQB-0 means IQB w i t h no predry ing . Deep bed means deep bed s team blanching .

73

Table A10. CHARACTERISTICS OF EFFLUENTS GENERATED DURING POTATO BLANCHING

cogen

%2 ( P P 4

12

11

16

10

1 3

1 2

11

16

a Trea t men t

number

lKIT

2 POT

3POT

4POT

5WT

Averages

IQB-6.9

IQB- 0

Deep bed

NO2

.29

.05

.09

.09

.05

( P P d

.29

.06

.09

Treatment number

lPOT

2WT

3POT

4POT

5WT

Ave rages

IQB-6.9

IQB- 0

Deep bed

BOD ( P P d 5000

4030

3780

4260

4720

5000

4340

3780

J o l a t i l e so l i d s ( P P d

7440

6010

8000

5 720

5550

7440

5760

8000

COD

(ppm> 6 340

4500

3640

4370

5790

6 340

4890

3640

T o t a l s o l i d s

C%) 0.930

0.746

1.01

0.707

0.856

0.930

0.770

1.01

7 75

1080

1490

1 7 1

1270

775

842

1490

.081

.114

,156

.020

.133

,081

.089

.156

T o t a l phosphorus

85

66

102

65

78

(PPm)

85

70

102

So lub l e phos phoixs

(PFd

48 46

57

4 1

52

48

47

57

T o t a l o rgan ic n i t r o g e n

(PPm)

302

264

39 7

249

329

302

281

39 7

Ni

NH3 (PPm)

24

20

36

23

25

-

24

23

36

-

PH

6.9

7.1 6.9

7 .O 6.9

-

6.9

7.0

6.9 -

a See foo tno te a n d ' t r e a t m e n t number on Table A9.

74

Blanchinga t r e a t m e n t

IQB- 5.6

IQB-0

Deep bed

IQB- 0

IQB- 0

Averages

IQB-5.6

IQB- 0

Deep bed

Table A l l , I N D I V I D U A L BLANCHING TRIALS FOR BEETS

Treatment number I

1 B

2B

3B

4B

5B

e l t : Hea3 :g /m

6.49

7.66

6.40

6.88

6.44

6.49

7.00

6.40

lading E f f l u e n t 1 Product '-1 g e n e r a t i o n y i e l d

27.62

32.55 --

29.28

27.47

27.62

29.77 --

1.48

1.84

1.68

1.61

1.74

1.48

1.73

1.68

I 86.3

87.8

~ 89.4

90.0

88.8

86.3

88.9

89.4

S o l i d s l o s t as product

5.21

4.01

5.26

3.76

4.29

(%>

5.21

4.02

5.26

a IQB-5.6 means I Q B w i t h a 5.6% weight r e d u c t i o n p r i o r t o b l anch ing . IQB-0 means IQB w i t h no p red ry ing . Deep bed means deep bed s t e a m b l anch ing .

75

Table A12. CHARACTERISTICS OF EFFLUENTS GENERATED DURING BEET BLANCHING

a Treatment number

1 B

2 B

3B

4B

5B

Averages

IQB-5.6

IQB- 0

Deep bed

Treatment number

1 B

2 B

3B

4B

5B

Averages

IQB- 5.6

IQB- 0

Deep bed

BOD ( P P d

29400

16700

21500

28600

19200

29400

2 1500

2 1500

V o l a t i l e s o l i d s (PPI 33600

20800

29000

21500

23100

33600

21800

29000

COD ( P P 4

29700

22600

25700

19200

25000

29700

22300

2 5 700

;uspended v o l a t i l e

so l i d s ( P P I

3 78

156

2 14

224

170

3 78

183

2 14

T o t a l s o l i d s

(%)

3.89

2.36

3.34

2.46

2.64

3.89

2.49

3.34

Suspended s o l i d s

( X I .056

,017

.022

.027

.021

.056

.022

.022

T o t a l phosphorus

( PPm)

145

9 1

136

98

95

145

95

136

~~~ ~

Soluble phosphorus E

(PPmI

- Nil

m 3 PPmI

105

60

108

61

64

105

62

108 -

Tota l o rgan ic n i t r o g e n

( P P d

556

349

492

378

379

5 56

369

492

PH

6.6

6.6

6.5

6.7

6.6

-

6.6

6.6

6.5 -

a b See foo tno te and t rea tment number on Table A l l .

I n t e r f e r e n c e i n tes ts f o r s o l u b l e phosphorus, N02-N and NO - N . 3 76

Table A13. INDIVIDUAL BLANCHING TRIALS FOR CARROTS

a Blanching T r ea tmenl t r ea tmen t number

IQB- 0 1 CAR

Deep bed 2CAR

IQB-0, 3CAR

IQB- 0 4CAR

Averages

IQB- 0

Deep bed

- - B e l t

.g /m

9.86

6.01

9.86

8.64

- Hea5. -

9.45

6.01 -

.oading Ho Id

(kg /m2 )

41.82 --

41.82

36.60

40.06 --

E f f l u e n t g e n e r a t i o n

(1. /case)

1.30

1.49

1.27

1.27

1.28

1.49

a IQB-0 means IQB wi thout predrying. Deep bed means deep bed steam blanching.

Product y i e l d

91.6

88.4

91.9

91.9

(% 1

91.8

88.4

S o l i d s l o s t as product

(%)

1.54

2.77

1.86

2.39

1.93

2.77

77

Table A14. CHARACTERISTICS OF EFFLUENTS GENERATED DURING CARROT BLANCHING

I BOD

a Treatment

numb e r ( P P J

1 CAR 8340

2 CAR 11700

3 CAR 10200

4 CAR 12500

Averages

IQB-0 10300

Deep bed 11 700

I I I I T o t a l T o t a l T o t a l o rgan ic

COD s o l i d s phosphorus n i t r o g e n ( P P d (%> (PPm) (PPm)

10600 1.02 66 439

12 100 1.56 1.00 623

10700 1.25 81 512

16400 1.61 106 649

12600 1.29 84 533

12100 1.56 100 623

phosphorus ( P P d

Trea t men t number

1 CAR

2 CAR

3CAR

&CAR

Averages

I Q R - 0

Deep bed

NH3 NO; NO2 (ppm) (PPm) (PPm)

Suspended V o l a t i l e vol-at i l e i s o l i d s s o l i d s

10600 j 283

59

100

80

97

79

100

39 30 25

56 44 36

40 38 33

48 49 29

42 39 29

56 44 36

12500

a See foo tno te and t rea tment

835

Suspended s o l i d s

(%>

.034

.044

.029

.097

.053

.044

10600

12 700

Soluble

429

436

number on Table A14.

pH 5.1

5.8

5.9

5.5

5.5

5.8

78 *U.S. GOVERNMENT PRINTING OFFICE: 1974 546-3181377 1-3