Activity Trianglesensory

8/10/2019 Activity Trianglesensory

1/6ensory Evaluation | Triangle Sensory Test with Oreo Cookies

The fol lowing experiment was prepared as part of the University of Maines

NSF GK-1 2 project by NSF Fellow Beth Calder, Mary Ellen Camire, an d Susan

Brawley.

Sensory science is a scientifi c method used to measure, analyze, and

in terpret hum an responses to products as perce ived t hrough the i r senses

of touch, ta ste , s ight, sm el l , or sound. Sensory sc ience is o f ten used to

imp rove exist ing products or to test people s v iews on new products, such

as t he softness of t issues, the crunchin ess of an appl e var ie ty, or the aroma

of a i r f resheners. It is a lso used to test the tast e and co lor acceptance

of new products, such as pu rp le ketchup, or the sound charact er is t ics o fproducts, as in t he crunch of snack f oods.

There are many diff erent types of sensory tests . Attr i but e Diff erence tests

ask: How does a cer ta in qual i ty or t ra i t d i f f er between samples? Affect ive

sensory tests ask: What is the consumer acceptance of a product(s)?

Overal l Difference tests ask: Does a sensory dif ference exist bet ween

samp les? A Tr iang le test is a type of D i f f erence test to determine i f t here is

a sensory dif ference between two products. For exam ple, a researcher ma y

want to see i f changing one ingred ient in a recipe to make a cer ta in food

product wi l l a f fect the tast e o f the fi na l product. Three coded samples are

presented to each panel is t , and each panel is t is asked to p ick out which

sam ple they feel is di ff erent from t he oth er two. There are also sensory

tests which pa nel is ts have to be tra ined to detect tast e thresholds (su

as determin ing the concentra t ion of a fl avor which can be ident ifi ed

by the panel is t when in t roduced in t o a food product) or to have

tra ined panel is ts descr ibe cer ta in ch aracter is t ics th at researchers are

in terested in studying.

Sensory tests have to be conducted under control led conditions to redu

bias (prejudice or infl uence) on how panel ists view the product(s). The

sensory room ha s to b e free from d istract ions (sound, odors) to not

infl uence peoples decisions of the product. Sensory testing laboratorie

are ab le to ad just the l ight ing, a i r regu la t ion, and ind iv idua l boothsaccord ing to the needs of each sensory test t hat is conducted. Sample

a lso have to be presented in a random order and assign ed product

codes, such as t hree-d ig i t sam ple numb ers, to keep food products

anonymous to furt her reduce infl uencing t he panel ists decision. The

sensory test measures i f any differences detected are truly signifi cant

analyzing the sensory data f or s ta t is t ica l s ig n ifi cance. After s ta t is t ica

analys is, the researchers can ma ke a meaningfu l i n terpreta t ion from t

resu l ts o f t he sensory data.

R e f e r e n c e s

Meilgaa rd, M, Civi l le, GV, Carr, BT. 199 9. Sensory Evalua tion Techniqu e

3rd ed. Boca Raton: CRC Press LLC.

T R I A N G L E S E N S O R Y T E S T W I T H O R E O C O O K I E S

B a c k g r o u n d



T R I A N G L E S E N S O R Y T E S T

W I T H O R E O C O O K I E S

A d m i n i s t r a t o r s G u i d e

The fo l lowing exper iment wa s prepared as p ar t o f th e Univers i ty o f Maine s

NSF GK-1 2 project by NSF Fel low Bet h Calder, Mary El len Cam ire, and

Susan Brawley.

Gr a d e l e v e l s : 2 - 1 0

E st i m a t e d P r e p a r a t i o n Ti m e : 3 0 m i n u t e s

E st i m a t e d A c t i v i t y Ti m e : 1 c l a s s p e r i o d ( 4 5 m i n u t e s t o 1 h o u r )

S t a n d a r d A d d r e s s e d : C o n t e n t S t a n d a r d A ( S c i e n c e a s I n q u i r y )

Mathema tics is essent ia l in sc ient ifi c inqu i ry. Mathematica l too ls andmodels gu ide and im prove the posing of quest ions, gather ing data,

construct ing exp lanat ions, and communicat ing resu l ts .

R e f e r e n c e :

Lawless, HT and Heym ann, H. 1998 . Sensory Evaluat ion of Food:

Principles and Practices. New York: Chapman & Hall .

Meilgaa rd, M, Civi l le, GV, Carr, BT. 199 9. Sensory Evalua tion Techniqu es.

3rd ed. Boca Raton: CRC Press LLC.

O b j e c t i v e s :

To introduce sensory science to students

To have students vo luntar i ly par t ic ipat e in a sensory test

To learn more about hypothesis test ing and sta t i s t ica l s ig n ifi cance

M a t e r i a l s :

Low-f a t Oreo cookies wi t h normal cream fi l l ing ( t o ta l should equ

1.5 t imes the number o f s tudents)

Original Oreo cookies with normal cream fi l l ing (total should be

t imes the number o f s tudents)

Exa mp le : I f there are 12 students in the c lass you wi l l need at le

18 Low-f at Oreo cookies and 18 regul ar Oreo cookies

Smal l whi t e paper p la tes

Marker

Sensory bal lots (samples are provided)

6-8 oz. p last ic cup s (one for each stud ent)

Water

(Other products tha t could be used include regular and low- fat cheese

regular and low-f at graham crackers. Be aware that some students m

have food al lerg ies, sensi t iv i t ies, or d ietary restr ict ions.)

Se t - u p P r o c e d u r e s :

Using the marker, labe l the smal l whi te p la tes wi th rand om three-d1 .

codes ( the num ber o f p la tes for each code should be equal to ha l f o

number of cookies needed).

E x a m p l e : Random three-d ig i t sam ple codes:

767 - Orig ina l Oreo cookie sample

189 - Orig ina l Oreo cookie sample

312 - Low-f a t Oreo cookie sample

570 - Low-f a t Oreo cookie sample

12 students need at least:

18 Low-f a t Oreo cookies therefore, 9 p la tes should be labe led

and 9 p la tes should be labeled 189

18 regular Oreo cookies therefore, 9 plates should be labeled

and 9 p la tes should be labeled 570

Prepare the order of presentat ion for each student hal f t he stud2 .

should receive two low-f a t Oreos and one regular , and t he other ha l f

the students should receive two regular Oreos and one low-fat Oreo.



E x a m p l e : Suggested ba la nced random code presentat ions:

Student #1 receives sample order: 76 7,312,18 9

Student #2 receives sample order: 76 7,312, 570

Student #3 receives sample order: 767 ,189 ,570

Student #4 receives sample order : 312,189 ,570

Student #5 receives sample order : 312,189,767

Student #6 receives sample order : 570,312,18 9Student #7 receives sample order: 18 9,570,76 7

Student #8 receives sample order: 18 9, 570,312

Student #9 receives sample order: 189,767,312

Student #10 receives sample order :570,76 7 ,312

Student #11 receives sample order :570,767,189

Student #12 receives sample order :312,570,767

Student #13 rece ives samp le order the same as Student # 1

and so on

Prepare a sensory bal lot for each student.3.

Photocopy enough ballots for each student and write t he order for each student on the blank li nes as shown in the example on the previous page.

Tr iang le Sensory Test o n Cookies

Please take a drink of wa ter before ta st in g cookie sam ples. Eat cookie sam ples from l eft

to r ight , and p lease take a s ip o f w ater between sam ples.

Place an X under the cookie which is different than the others.

Comments:

CUT



Se n s o r y Te s t P r o c e d u r e s :

In troduce the top ic o f sensory sc ience to fami l ia r ize students.1 .

a . Try not to b ias st udents wi th the in troduct ion. Just m ent ion to

students t hat t hey wi l l be par t ic ipat ing in a Tr iang le sensory test .

b . Students can vo luntar i l y par t ic ipate, but should not be forced to

part ic ipat e because a l l sensory tests th at inc lu de human sub jects

must be conducted on a vo luntary basis. Exp la in to stud ents, i f they

part ic ipat e, that sensory panel is ts have to remain s i lent dur ing t he

taste test and cann ot share answers wi th th e i r neighbors. Expla in

that there wi l l be a d iscussion after the test to share answers.

In troduce the exper iment t o the students.2 .

a . Ment ion to students t hat t hey wi l l be g iven three cookies, and that they

should tast e the cookies from le f t t o r ight. They should t ake a s ip o fwater between each sampl e.

b . The ob ject o f t he test is to m ark which of the cookies is d i f ferent f rom

the other two. Only one cookie out of the three should be marked as

being d i f f erent. I f s t udents have d i ffi cu l ty decid ing, ment ion to th em

that i t is acceptab le i f they want to go back and for th and re- taste

sampl es to determine the d i f ferent cookie .

c. They may have to re- tast e samples, so exp la in t o students t hat they

may not want to eat the whole cookie a l l a t once, but wai t unt i l t he

test is over before eating the entire cookie sample.

d . I f th ey cannot te l l whi ch cookie is d i f f erent, te l l t hem to guess.

e. Use the provided sensory bal lot as a guide, i f needed.

Begin th e exper iment.3 .

a. Pass out sensory bal lots, cookies on labeled plates with random codes,

and water .

b . Al low th e students to begin t he sensory test . Enforce the qu ie t ru le

dur ing the sensory test .

Col lect t he ba l lo ts.4 .

a. Optional: After the bal lots are col lected, explain the hypothesis of

the sensory test.

b. The stated scientifi c question is:

i . Can the c lass detect a d i f ference between low-fa t a nd regular

(origina l) Oreo cookies?

i i . Hypothesis test ing an d in t roducing the sc ient ifi c m ethod could

used in th is lesson.

Hypothesis Testing Basics: The nul l hypothesis (HO) is presume

true unt i l s t a t is t ica l ev idence in the form of a h ypothesis test

ind icates o therwise t hen you can re ject the nu l l hypothesis in

support o f th e a l ternat ive hypothesis (Ha).

For exam ple:

Ho: Students o f t he c lass cannot te l l a d i f f erence between low-f

and origina l Oreo cookies.

Ha: Students o f the c lass can te l l a d i f f erence between low-fa t

and origina l Oreo cookies.

Tal ly sensory bal lots to determine the number of correct and5 .

incorrect responses.

a. Opt iona l : There is a sta t is t ica l tab le (T8, pg. 369 of Mei lgaard et

1999 or T4.1, pg. 130 of Lawless and Heymann, 1998) t hat ca n bused to determine i f t he c lass was ab le to detect a

d i f f erence between t he low-fa t and or ig ina l Oreo cookies th at w as

stat i s t ica l ly s ign ifi cant. To use: the tab le should be set a t 0 .05 an

n= to the to ta l number o f pa r t i c i pa t i ng s tuden ts .

i . In th is case s ince the leve l w i l l be set a t 0 .05, the resu l ts wi l l

be sta t is t ica l ly s ign ifi cant i f the d i f f erence between the tw o

products would ha ve occurred by chance a lone in less than 1

t ime i n 20 t imes .

i i . Sta t is t ica l ly s ign ifi cant m eans that t he l ike l ihood is low that

the d i f ference found between the t wo products occurred by

chance alone.



b. After determin ing fi na l resu l ts , in t erpret t he fi nd ings b ack to t he

students. For examp le: The c lass wa s ab le (or not ab le) to detect a

sta t i s t ica l ly s ign ifi cant d i f ference between low-fa t and or ig ina l

Oreo cookies.

Have a c lass d iscussion wi th students and g et the i r input.6 .

a. The company that makes Oreo cookies may fi nd the results

in terest ing that th is par t icu lar grade level was ab le to detect (or not

detect) a signifi cant difference between the two kinds of cookies.

b . Sensory tests can p rovide companies wi th va luable in forma tion such

as th e acceptab i l i ty o f a new cookie .

i . I f t he sensory test resu l ts are promis ing, t he company may fi nd i t

worthwhile to produce the cookies.

i i . I f a comp any produced cookies and t hen so ld them wi t hout

conduct ing sensory tests, they could potent ia l l y be tak ing alarge r isk and lose a lo t o f m oney producing a food product that

wi l l not se l l .

c. If they were able to detect a difference, what sort of sensory

dif ferences were they able to perceive between t he tw o cookies? Any

texture, fl avor, or color dif ferences? (In previous s ensory tests,

students have mentioned that low-fat Oreo cookies have a slight

coffee fl avor, are sl ightly l ighter in color, and are crunchier than the

or ig ina l . )

i . Another d iscussion can be in troduced as to what propert ies

fat can add to cookies, for example, more fl avor or softer

textura l qua l i t ies.

i i . A good fi nal question to ask the students is: How well did the

food and sensory sc ient is ts m eet t he chal lenge to make t he

cookie lower in f a t , but t ry to re ta in good fl avor qual i t ies o f t he

original Oreos?



B a c k g r o u n d : When a food company is o f fer ing a new product,

changing ingred ients, or research ing potent ia l products, i t s im portant f or

them t o know what the consumer react ion is l ike ly to be and th e impact o f

th e key chara cterist ics of the product on their reaction. Sensory science

is the d isc ip l in e in which f ood scient is ts d evelop and execute test ing

to eva luate a t t r ibutes o f food products. There are three basic types of

sensory tests that are rout ine ly used in pract ice:

Discr im inat ion or d i f f e rence tes ts 1 . are used to answer whether there

are any dif ferences between two types of product s. For exam ple, when a

food company fi nds an a l ternate ingred ient t o inc lude in a food product,

they want t o confi rm that consumers cannot te l l t he d i f ference between

the or ig ina l product and t he newly formulated product. One type of

d iscr imina t ion test is the Tr iang le test , in wh ich three coded sam ples

are presented to each panel is t , and each panel is t is asked to p ick out

which sam ple they feel is d i f ferent f rom t he other two.

Descr ip t i ve ana lyses2 . are methods used to qua nt i f y the perceived

in tensi t ies o f a product s sensory character is t ics. Th is techniqueis used to assess how food products are s im i lar or d i f f erent f rom

one another. Using t he examp le above, i f i t i s determined that the

two products are d i f f erent, descr ip t ive an alys is ident ifi es which

character is t ic o f t he food products cau se them to be d i f f erent.

3 . Af fect i ve or hedon ic tes ts are used to quan t i fy th e degree of

preference for a product. These tests measure how wel l products

are l iked or which product s are preferred. Returnin g to our exam ple,

a f fect ive tests w i l l assess whether the new product is l iked m ore or

less when comp ared to the origin al product . Thus, al l three sensory

test ing m ethods can be used to provide d i f ferent in f ormation dur ing t he

development o f food products.

O b j e c t i v e : To learn ab out sensory science

P r o c e d u r e s :

P lease take a dr in k o f wat er before tast in g th e cookie samples.1 .

Taste the cookie samp les from le f t t o r ight, and p l ease take a s ip o f2 .

water between samples.

On your ba l lo t , p lace an X u nder the cookie which is d i f ferent than3 .

the others. I t is okay to re- taste samples. I f you cannot te l l which

cookie is different, i t is okay to guess.

After you choose which sam ple you t h ink is d i f f erent, use t he tab le4 .

provided to descr ibe a l l t hree of t he samples.

D i s c u s s i o n Qu e s t i o n s :

Were you able to tel l a difference between the samples? If so, which1 .

sample d id you choose as the d i f ferent sample?

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Were you correct?2 .

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

If you were able to detect a difference, what sort of sensory3 .

differences were you able to perceive between the two cookies?

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Which sample d id t he major i ty o f the c lass choose as the4 .

d i f ferent sample?

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Were they correct? Was this statistical ly signifi cant?5 .

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Do you think a food company would fi nd these results interesting?6 .

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

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