PRODUCTION OF SUGARS FROM BANANA FIBRE

Sharifah Binti Mohammad (32830)

SUMMARY

Malaysia imports more than 90% of the raw material toproduce cane sugar, which is very costly. As such, new andhighly potential local raw material should be introduced inorder to fulfil the market demand and also to reduce theprice of sugar. Overall, this project is about theutilization of banana trunk or stem for the production ofsugars. It is an interesting alternative since banana trunks- often considered as a waste -has not being utilized beforeas a source of raw material from biomass. In fact,cellulosic waste content inside the biomass can be convertedinto food, fuel and chemicals. Through the enzymatichydrolysis technique, sugar can be produce from the biomassbanana stems. Both pre-treatment and enzymatic treatmentwill be applied in this process. This process will increasethe convertibility of glucose. Then, the sample will bepurified using powdered activated charcoal (PAC). Finally,the sugar will be crystallizing using oven drying method forone week at 60°C.Thesugar obtained can be used as a carbonsource in fermentation processes, which is potentiallybeneficial in generating various products. Also, the sugarsolution will be centrifuged and purified by filtration bygravity on powdered activated charcoal (PAC). The purifiedbanana sugar (PBS) will be crystallized by oven-drying at60oC. Hence, the production cost for sugars can be reduced,while overall production can be increased from the use oflocal biomass, concomitantly reducing environmentalpollution. This venture will also generate jobs and provideextra incomes to the local people.

Keywords: banana stem, sugar, cellulosic waste, enzymatichydrolysis, PAC

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1.0 INTRODUCTION

1.1 Background

The sugar industry in Malaysia is characterized by the rapid

increase in direct domestic consumption amplified by an

equally fast growing food processing industry (FAO, 1997).In

order to meet the domestic demand, Malaysia imports more

than 90% of the raw material to produce cane sugar, which is

very costly (Adam,2010). Overall, domestic consumption of

sugar has increased rapidly over the years. On a caput per

basis, the amount of sugar consumption in Malaysia is about

50 kg (raw equivalent), one of the highest in the region.

Due to high import of raw materials the cost of the

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production will be increase. Therefore the dependent of

imported raw material need to be reduced.

In this project, banana stem waste from Musa balbisiana sp.

will be utilized as the raw material for the production of

sugar. Musa balbisiana sp. in its hybrid forms are not widely

cultivated itself, because its fruits contain a high

proportion of seeds. The sugar is being produced through

sequence steps in enzymatic hydrolysis of the banana stem

waste which is mainly into glucose. In this project, both

pre- treatment and enzymatic treatment is the crucial method

in order to maximize the production of sugars. The work

consisted of three stages: production of hydrolysed banana

sugar, purification and crystallization of the purified

sugar.

Biomass is categorized as the best alternative methods in

producing sugar. It is very cost effective. Spano et al.,

(1976) found that the conversion of cellulosic waste is very

effective in producing glucose syrup through enzymatic

hydrolysis methods. During the harvesting of banana fruit,

the pseudo-stem or trunk will be discarded and left to

degrade, which may cause environmental pollution if

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performed on large plantations. As such, this biomass should

be wisely utilized and processed into value-added product

like sugars.

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1.2 Problem statements

This project attempts to study and solve the following

problems:

Lack of raw material to produce sugar from sugar cane.

Disability of sugar cane plantation to provide

sufficient raw material to produce sugar. The industry

need to import 90% (about 1 million tons) of raw

material to produce sugar.

Increasing sugar production in Malaysia.

Due to the increase in population, the consumption of

sugar also increases. Unfortunately, the sugar industry

cannot afford to provide sufficient sugar for domestic

use and the government have to import raw sugar from

other countries.

Reduce environmental pollution by reusing waste biomass

Usually, after harvesting banana fruit, the banana

stems are always left behind either to be burn or

thrown away. Therefore, by reusing the biomass waste in

order to produce sugar, it can slightly reduce the

environmental pollution caused by the biomass.

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1.3 Objectives

The objectives of this project are to:

Produce and to maximize the production of sugars from

banana stem fibre

utilize the banana stem as an alternative biomass to

produce sugars

develop techniques in purification and crystallization

of sugars

Increase the economic income from the banana

industries.

2.0 LITERATURE REVIEW

2.1 Sugar Industries

Sugar is an essential item for food and it is widely traded

commodity. Sugar consumption is expected to grow steadily in

Malaysia, reflecting the increasing income and growth of

population. About 66% of total sugar consumption in Malaysia

is categorized in domestic uses. Most (90%) of sugar supply

is imported and has reached a record of 1.0 million tons.

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The wholesale and retail for refined sugar in Malaysia is

control under the Supplies Regulation Act 1974 and have

remained at RM 1,145 (US$452) per ton and RM1.20 (US$0.47)

per kilogram (FAO, 1997).

In Malaysia, sugar is derived from sugar cane. It is a very

easy and profitable plant to grow but it is rather

ineffective in reproducing naturally

(Braun,1999).Unfortunately, the sugar processing industries

in Malaysia still depends on imports for about 90% of its

raw material. The lack of raw materials and the increase in

industrial application of cane sugar naturally leads to

higher price of this commodity. In Sarawak, the starch from

sago palm has also great potential for commercial production

of sugars (Bujang, 2011) and it is reported that the

hydrolysis of treated sago hampas can produce up to 40% to

80% of sugar in lab-scale.

2.2 Banana Plantations in Malaysia

In Malaysia, banana is the second most widely cultivated

fruit, covering about 26,000 ha with a total production of

530,000 metric tonnes. Banana is mainly produced from Johor,

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Pahang and Sarawak (Mokhtaruddin &William, 2011). Banana can

grow as perennial crop where the plant is allowed to produce

continuous shoots from the stem. Banana fruit is one of

abundant fruits in Malaysia. There are about a thousand

species of banana plants; most of these are edible although

some are not. Banana fibre is widely used into the

production of value added products such as commercial

sugars. In order to obtain banana fibre, the stem of banana

tree is peeled and brown-green skin is thrown away. Only

clean or white portion of the left over stem will be taken

and processed. The fibre is best extracted from the banana

stem, which can be utilized as the raw material to produce

sugar.

2.3 Classification of Banana

Banana is the common name for a fruit and also herbaceous

plant of the genus Musa which produce the commonly eaten

fruit. Largely fibre can be extracted from the type Musa

balbisiana sp. (Spano et al., 1996) found that the cellulosic

waste can be converted into food, fuel and chemical through

enzymatic hydrolysis. Utilization of biomass such as banana

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stem waste is very important from environmental, industrial

and agricultural perspective (Lam & Malikin, 1994).

2.4 Enzymatic Hydrolysis of Banana Stem

The production of marketable products from starch mainly can

be achieved by acid or enzyme hydrolysis. Each procedure is

generally associated with its own unique problems. The

disadvantages of using acid hydrolysis are relatively low

product yield and formation of excessive by- products

(Govindasamy et al., 1997). In contrast, the use of enzyme in

starch hydrolysis will be more specific, reproducible,

sensitive and environmental friendly. Therefore, the latest

procedure is highly recommended.

Recent research focused on the use of microbial enzymes for

the hydrolysis of starches. This is usually achieved by

using two enzymes which are involved in two reaction steps

namely: liquefaction and saccharification. Bujang et al.

(2000) reported the hydrolysis using 0.5 µL/g of Thermamyl-

120 L at pΗ 6.5, 80-90 ̊ C during liquefaction and 0.6 µL/g

of Dextrozyme 225/75 L at pΗ 4.5, 60-65 ̊ C generated a 98%

recovery of glucose from sago starch after only 4 hours.

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2.5 Purification of Sugar on Powdered Activated Charcoal

(PAC)

Activated charcoal is a solid, porous, black carbonaceous,

tasteless material which is microcrystalline and non

graphitic form of carbon (Ang et al., 2006). It is prepared

from wood and vegetables and can be produced either by gas

(steam) or chemical activation. The activities of activated

charcoal can be divided into adsorption, mechanical

filtration, ion exchange and surface oxidation. Physical and

chemical characteristics of the adsorbate, concentration of

adsorbate in liquid solution, characteristics of the liquid

phase as well as the flow rate or contact time of adsorbate

with adsorbent also affect the adsorption capacity (Ang et al.,

2006).

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3.0 MATERIALS AND METHODS

3.1 Materials

3.1.1 Banana Trunk/Stem

Banana trunk/stem (Figure 1) will be collected after the

banana harvesting period from the Kampung Meranek, in

Kota Samarahan and transferred promptly to the

laboratory in order to avoid degradation of the banana

stem.

Figure 1: Arrow shows the banana trunk or stem for use in this

project.

3.1.2 Blender

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A laboratory appliance used to mix, puree,

or emulsify food and other substances. A stationary

blender consists of a blender jar with blade at the

bottom, rotated by a motor in the base. The

newer immersion blender configuration has a motor on top

connected by a shaft to a blade at the bottom, which can

be used with any container.

3.1.3 Enzymes

The enzyme that will be used for enzymatic treatment

will be obtain from Novozyme and supplied by Novozymes

Biomass Kit (Janggu and Bujang, 2009).

3.1.4 Cellulase

The suggested condition for this enzyme is pH 4.5 and

temperatures at 45°C and enzyme concentrations at 20%

(v/w). Cellulase catalyzes the breakdown of

cellulosic materials into mainly glucose and cellobiose

(Janggu and Bujang, 2009).

3.1.5 β-glucosidase

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β-glucosidase assists cellulase in cellulose

depolymerisation by cleaving cellobiose into glucose.

This is important since cellobiose is not a fermentable

sugar, hence supplementing with cellobiose will

maximize total sugars production from hydrolysis of

banana fibre. The optimum concentration of β-

glucosidase is 0.5% (v/w).

3.2 Methods (Refer to Appendix)

3.2.1 Preparation & Filtration of banana stem

Exactly 1kg (fresh weight) of banana stem will be chopped into

smaller cube pieces (which is about 1cm3 approximately).

After that, the raw chopped banana will be mixed with 1:1

volume of distilled water (DS) in a blender for about 5- 10

minutes. After the blending process, the banana stem just now

is being filtered manually through muslin cloth in order to obtain

the fibre. Finally, the banana fiber is ready for pre- treatment

process.

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3.2.2 Pre-treatment

About 7% or 10% of the sample blended will undergo pre-

treatment to see which sample is more reliable. Samples then

will undergo boiling process for 30 minutes. This process show

equivalent performance as steaming but prove to give more

economic solution (Janggu & Bujang, 2009).

3.2.3 Enzymatic hydrolysis of solid form

Approximately 5%, 10% and 15% (w/v) of solid form from

sample of pre-treatment will undergo enzymatic

treatment at two difference processes, subsequent

mixing and also direct mixing.

a) Subsequent mixing

The appropriate amount of solid sample will mix

with 20% (v/w) of enzyme Cellulase and 0.5% (v/w)

of β-glucosidase enzyme at 45oC and pH 4.5. This

process will take 16 hours to process. After that,

0.1% (v/w) of enzyme complex will added into

mixture for 4 hours process.

b) Direct mixing

Direct mixing will be applied to appropriate

amount of solid form from pre-treatment sample.

The sample will mix with β-glucosidase, Cellulase

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and Enzyme Complex at 0.5%, 20% and 0.1% (v/w),

respectively. Process of enzymatic hydrolysis

will undergo under optimum condition of 45oC and pH

4.5.

3.2.4 Enzymatic hydrolysis on liquid syrup

On the other hand, liquid syrup from pre-treatment and

grinding processes will undergo enzymatic hydrolysis to

recover some sugars from residual starch in the liquid.

Enzymatic hydrolysis will undergo two steps:

a) Liquefaction

The enzyme will be use is Termamyl SC (α-amylase).

This enzyme catalyzes the hydrolysis of the a-1, 4

glycosidic bond of starch. In addition, it helps

in inducing partial hydrolysis of starch and

reduces viscosity. The process for liquefaction

will take 2-3 hours at 90oC.

b) Saccharification

Saccharification process will use enzyme

Dextrozyme (glucoamylase) where it will help

remove β-glucose units of starch by catalyzing the

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hydrolysis of both α-1, 4 and α-1, 6 glycosidic

bond. This process will undergo 2-4 hours with 60

oC of the temperature.

3.2.5 Purification of Sugar

Powdered Activated Charcoal (PAC) will be used as the

absorbent to purify the sample. Before that, the sample

will be centrifuged and filtered to collect suspension

needed. Impurities will be apart during the

purification. The PAC will be pack in columns of 2.5cm

diameter and 50cm length (Booty & Bujang, 2009). The

highest recovery of pure sugar is using 5g of PAC

compare to 10g of PAC (Bujang et al., 2012).

3.2.6 Crystallization of Sugar

The purified liquid sugar will be concentrated by

distillation. Concentrated glucose syrup will be

crystallized using oven. (Bujang et al., 2011)

reported that oven drying give 100% recovery of sugar

for crystallization. The sample will be dried in oven

at 60 to 70°C for one week.

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3.3 Analytical Methods

3.3.1 Biomass (Dry Cell Weight Determination)

In this method, the samples will be centrifuge at 8000

rpm for 15 minutes at 4°C. Then, the supernatant for

reducing sugar will be collected and kept at 4°C. The

cell pellet will be suspended with distilled water and

will be centrifuged again. Next, the cell free

supernatant will be discarded. The tube containing cell

pellet will be dried overnight at 80°C until the weight

is constant. Finally, the centrifuge tube will be

reweighed and the dry cell weight will be determined by

following formula:

DCW (g/L) = [wt of centrifuge + cells] g – [wt of

centrifuge tube] g × 103

Sample volume (ml)

3.3.2 Sugar Analysis/DNS Method

Analysis of reducing sugars was based on

dinitrosalicyclic acid (DNS) method (Miller, 1959).

About 3mL of diluted Hydrolyzed Banana Sugar or

Purified Banana Sugar is being mixed with 3mL of DNS

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solution in a test tube. The mixture will be boiled for

about 15 minutes and cooled before adding with 1mL 40%

Rochelle salts. The measurement will be made by using

UV/Visible spectrophotometer (Ultra spec 1100- Pro) at

575 nm. Spectrophotometer will be used to analyze the

amount of glucose. The result will show the recovery of

glucose after purification. The conversion of glucose

into reducing sugar by enzyme will be expressed as

dextrose equivalent (DE), defined as percentage of

reducing sugar present on a dry solid basis. Glucose

conversion from banana fibre starch will be calculated

as follows:

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Glucoseconversion (% )=AB×100%

Where, A= glucose concentration in slurry after

hydrolysis (g/L)

B= amount of dry banana fibre starch used

for hydrolysis (g/L)

3.3.3 Starch Analysis (Iodine Method)

Exactly 0.2g of iodine crystals and 2g of Potassium

Iodide will be prepared in 100mL distilled water in

order to get iodine solution. Next, 0.1mL iodine

solution will be added to 1mL of diluted sample. Then,

the solution will be adding more with distilled water

until it reached to 10mL. The OD reading will be

measure by using UV/Visible spectrophotometer (Ultra

spec 1100- Pro) at 590nm.

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4.0 EXPECTED OUTCOMES

1. It will be possible to produce and to maximize the

productions of sugars from banana stem fibre

2. It will be possible to utilize the banana stem as

an alternative biomass in order to produce sugars.

3. Techniques in purification and crystallization of

sugars can be developed and studied throughout

this project.

4. Economic income from the banana industries will be

increased drastically.

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5.0 RESEARCH SCHEDULE

Project Activities2013 2014

Sept Oct Nov Dec Jan Feb Mac Apr May Jun Jul

Proposal Writing & Presentation

Collection of banana stem

Processing of banana stem

Analyses of banana stem

Processing of fibre to sugar

Progress report

Data analysis by statistical analysis

Report Writing & Presentation

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REFERENCES

Adam. (2010). Parliament: Malaysia imports 99 % sugar supply. Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur, Malaysia

Ang, S.Y.; Bujang, K.B. and Adeni, D.S.A (2006).Purification of Lactic Acid from Hydrolyzed Sago StarchFermentation by Powdered Activated Carbon (PAC):Adsorption Isotherm and Kinetic Studies. Proc. 31stAnnual Conf of the Malaysian Soc. for Biochem & MolBiol. 17th August 2006.

Booty, H.B. and Bujang, K.B. (2009). Maximising Productionof Sugars from Enzymatic Hydrolysis of Various StarchSources, Compared to Sago Starch. Proceedings of the1st ASEAN Sago Symposium. Kuching. 29-30th October,2009. Pg: 70-73.

Bujang, K.B. and Ahmad, F.B. (2000). Country Report ofMalaysia; Production and Utilisation of sago starch inMalaysia. International Sago Seminar. Pp 1-8.

Bujang, K.B.; Monib, N.J.; and Nolasco-Hipolito, C.(2012). Production and Purification of Sago Sugar. Proc. 2nd

ASEAN Sago Symposium. Coorganised by UNIMAS, CRAUN, IPB& FAO. 29-30th October 2012.

Bujang,K.B.(2011). Potential of Sago for Commercial Productions of Sugars. The 10th International Sago Symposium. Bogor. Indonesia. 29-30th 2011

FAO(1997). Proceeding of the Fiji/FAO 1997 Asia PacificSugar Conference. Malaysia. Retrieved fromhttp://www.fao.org/decrep/005/x0513e/x0513e22.htm

Govindasamy, S.; Campanella, O.H.; Oates, C.G. (1997).Enzymatic Hydrolysis and Saccharification Optimisationof Sago Starch in a Twin- screw Extruder. Journal ofFood Engineering 32.

Janggu, U. and Bujang, K.B. (2009). Maximizing Sugar Productionfrom Enzymatic Hydrolysis of Sago Fiber for EthanolFermentation. Proceedings of the 1st ASEAN Sago Symposium.Organised by UNIMAS, collaborated with NUKLEAR (Malaysia),NECFER (Japan), Universitas Mulawarman Samarinda (Indonesia)

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and Institut Pertanian Bogor (Indonesia). Riverside MajesticHotel, Kuching. 29-30th October, 2009. Pg: 30-33.

L. A. Spano et al., (1976). Enzymatic hydrolysis ofcellulosic wastes to glucose. Retrieved fromhttp://www.sciencedirect.com/science/article/pii/0304396776900391

Lam, S. and Malikin, G. (1994). Analytical Application ofImmobilize Enzyme Reactors. Blackie Academic andProfessional. Great Britain, pp-86.

Miller, G.L. (1959). Use of Dinitrosalycylic acid reagentfor determination of reducing sugars. J. Anal. Chem.,31, Pp 426-428

Mokhtarud-din, H. and William, R. (2011). Status of Banana Cultivation and Disease Incidence in Malaysia. Retrieved from http://www.portal.doa.gov.my/perpeta/images/banana.pdf

T. Braun, (1999, October 3). Sugarcane. Retrieved October1, 2010 from Ethnobotanical Leaflets. Retrieved fromhttp://www.ethnoleaflets.com

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