Areation of Cereal Dough by Yeast-Lak

8/14/2019 Areation of Cereal Dough by Yeast-Lak

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SUGAR BOILING

Name: T.L.V.Peiris

Index No: GS/MSc/Food/3630/08


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MATERIALS

Measuring cylinders [500 ml]

Graduated pipettesConical flasks [500 ml]

Stoppers for conical flasks

Rubber tubingWater bath [40 0 C]

Perforated plungers

Mixing bowls

SpoonsWeighing scale

INGREDIENTS

Wheat flour 1500 g

Rice flour 150 gCorn starch 150 g

Malt 6. 75 g

20 % sodium chloride 135 ml

Potassium bromideSodium meta bisulphite [S M S]

YEAST - yeast Mauripan [instant dry yeast ]

PROCEDURE

THE EFFECT OF YEAST CONCENTRATION ON GAS PRODUCTION

The wheat flour was taken and three doughs [A, B, C ] were made based onthe following formulae by changing only the yeast concentration.

Water was added in such a way to make the total volume constant

.DOUGH

A B C

flour 50 g 50 g 50g

Malt 0.25g 0.25 g 0.25g

20 % salt solution 5 ml 5 ml 5 ml

20 % YEAST suspension 5 ml 10 ml 15 ml

AERATION OF CEREAL DOUGH BY YEAST Page 3


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Water 22 ml 17 ml 12 ml

All above ingredients were measured accurately and mixed using separate spoons inmixing bowls kneading with fingers to make the doughs with properly mixed

ingredients. Those three doughs were put into 500ml conical flasks.

A large plastic container and filled with water was taken.Three 500ml measuring cylinders were filled with water and were inverted in

that water container without trapping of air bubbles .

The three conical flasks which were prepared previously were connected to themeasuring cylinders using rubber tubes , and wax was applied to the connecting ends

to prevent escape of gas.

The volume of accumulated gas in the measuring cylinders were recorded every 15minutes until no more gas production was observed.

A graph was plotted with the results obtained.

RESULTS


Time /min Accumulated gas volume/cm3

A B C

15 - - 25

30 - 20 85

45 - 35 165

60 - 45 230

75 15 60 275

90 20 70 305

105 25 70 320

120 30 70 320135 40 70 320

150 40 70 320

165 40 70 320

180 40 70 320


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Effect of Yeast Concentration on Gas Production

0

50

100

150

200

250

300

350

Time(m

in)

1

5

3

0

4

5

6

0

7

5

9

0

10

5

12

0

13

5

15

0

16

5

Time (min)

GasAccumulation(

EFFECT OF TEMPERATURE ON GAS PRODUCTION

PROCEDURE

A mixture was prepared and dough was made according to the formula B

;ie; Flour 50gMalt 0.25 g

20 % salt solution 5 ml

20 % yeast suspension 10 mlWater 17 ml

This dough was put into a 500 ml conical flask and connected to a 500ml measuringcylinder that was immersed in water , using rubber tubing and the connecting ends

were sealed with wax.

The conical flask which contained the dough was put into a 40 o C water bath.

The temperature was kept constant at 40 0 C in the water bath throughout the

process and was conformed it using a thermometer .

The gas production of the dough was measured every 15 minutes until there wasno more gas production.



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Effect of Tem perature on Gas Prod

0

50

100

150

200

250

Time(min) 1

5 30 45 60 75 90 105

120

135

150

165

Time (mim

Gas

Acumulation(ml)

B @ 3

B1 @

EFFECT OF MALT EXTRACT



B (Room

temperature)

B1(at 40oC)

15 - 25

30 20 40

45 35 85

60 45 100

75 60 11090 70 140

105 70 195

120 70 220

135 70 220

150 70 220

165 70 220

180 70 220


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PROCEDURE

A dough was prepared using the ingredients in formula B but instead of malt

extract corn flour was used, so that the formula was as below,

Wheat flour 50g

CORN FLOUR 0.25g

20 salt solution 5 ml20 yeast suspension 10ml

Water 17 ml

The dough was kept in 500 ml conical flask and the apparatus was connected as

before and kept for gas accumulation.

The collection of gas was measured every 15 minutes until it reached a constant

value .

RESULTS

Time/min Accumulated gas volume/cm3

B (with corn) B11(with malt)

15 - -

30 20 -

45 35 10

160 45 20

75 60 25

90 70 25105 70 25

120 70 25

135 70 25

150 70 25

165 70 25

180 70 25



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Effect of Malt Extract

0

10

20

30

40

50

60

70

80

Time(mi

n)

15

30

45

60

75

90

10

5

12

0

13

5

15

0

16

5

Time (min)

GasAccumulation(ml)

B with malt

B II without m

EFFECTS OF SALT CONCENTRATION ON GAS PRODUCTION

PROCEDURE

Three doughs were prepared using following formulas and was put into 500ml conical flasks.

A B C

Flour 50g 50g 50g

Malt 0.25g 0.25g 0.25g

20SALT SOLUTION 0 5ml 10 ml20yeast suspension 10 ml 10ml 10ml

Water 22ml 17ml 12ml

The water was added to have a same volume in all three doughs.

Those three flasks were connected to 500ml measuring cylinders and gas wasallowed to collect .

The gas that was released was measured until there was no more accumulation

noted and a graph was plotted using the results.



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RESULTS

Effect of Salt Concentration

0

50

100

150

200

250

300

350

400

Time(min)

15 30 45 60 75 90 105

120

135

150

165

Time (min)

GasAccum

ulation(ml)

A with No S

B with 5ml s

C with 10ml



A B C

15 10 130 05

30 25 190 1545 35 250 25

60 50 300 40

75 75 330 50

90 100 340 50

105 130 350 50

120 130 350 50

135 130 350 50

150 130 350 50


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GAS RETENTION

EFFECT OF PROTEIN CONTENT AND FLOUR TYPEThe following doughs were made using the following formulas and were put in to

500ml measuring cylinders .

D1 D2 D3

Wheat flour 50g ---- -----Glutan + wheat flour --- 50g -----

Rice flour --- ----- 50g

Malt 0.25g 0.25g 0.25g

20 % salt solution 5ml 5ml 5ml20% yeast suspension 15 ml 15 ml 15 ml

Water 12 ml 12ml 12ml

The doughs were covered with paraffin oil and perforated plungers were puton top of the dough after making doughs to immerse in oil.

The initial oil levels above the each dough was measured.

The doughs were kept at room temperature and the oil levels were measured in

every 15 minutes until a constant level was achieved.A graph was plotted using the results.

RESULTS

The oil levels in each dough

D1 D2 D3

Initial oil levels 150 ml 150 ml 250 ml

Time [minutes ]

15 250 ml 250ml 250 ml30 275 ml 270 ml 250ml

45 275 ml 280 ml 250ml

60 275 ml 290 ml 250 ml75 280 ml 290 ml 250 ml

90 280 ml 300 ml 250 ml

105 280 ml 300 ml 250 ml120 280 ml 300 ml 250 ml

135 280 ml 300 ml 250 ml

150 280 ml 300 ml 250 ml



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CALCULATION

The gas retention [ml] in each dough was ,

D1 D2 D3Time [minutes]

15 100 100 0

30 125 120 045 125 130 0

60 125 140 0

75 130 140 0

90 130 150 0105 130 150 0

120 130 150 0

135 130 150 0

150 130 150 0

Gas Retention - Effect of Protein Contect and Flour type

0

20

40

60

80

100

120

140

160

Time(min)

15 30 45 60 75 90 105

120

135

Time (min)

GasRetention(ml)

D1(With Wheat)

D2 (Gluten +Whe

D3 ( Wth Rice Flo

As the gas that formed cannot escape through the oil layer , it get trapped inside

the dough causing the oil level to move up. So the oil level indicates the

gas retention ability of the dough with time.



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EFFECT OF ADDITIVES ON GAS RETENTION

PROCEDURE

The following ingredients were measured accurately .

A BWheat flour 50 g 50g

Malt 0.25g 0.25 g

20 % yeast suspension 10 ml 10 mlWater 17 ml 17 ml

0.05 g potassium bromide was taken and dissolved in 5 ml of 20 % salt

solution and was added to the mixture A .0.05 g sodium metabisulphite [S M S ] was measured and dissolved in 5 ml of

20% salt solution and was added to the mixture B.

Two doughs were made using the above A and B mixtures and were put into

500 ml measuring cylinders as before .The doughs were covered using paraffin oil placing the perforated plunger on top of

the dough. The initial oil levels were measured.The doughs were kept at room temperature , and the oil levels were measured in

every 15 minutes until there was no more change observed.

A graph was plotted using the results.

RESULTSOil levels [ml]

A [KBr] B [S M S]

Initial oil level 200 150

Time [minutes ]

15 200 150

30 230 20045 260 205

60 275 210

75 285 21590 285 215

105 285 215

120 285 215135 285 215

150 285 215



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DISCUSSION

Not only the formation but also the retention of gas is important in bakery industry.

This character is mainly determined by the quantity and the quality of the glutan

present in the dough. The glutan proteins namely glidin and glutenin are presentseparately in the flour and interact to form glutan with hydration and physical

manipulation during dough formation .

In this practical more gas retention was obtained with wheat flour , which containmore glutan than rice flour and even more gas retention in gluten added wheat

flour.

Out of the additives the KBr is a dough improver and SMS is a preservative.

The bromide added is converted to bromine and act as an oxidizer and made thedough with high air retention capacity. SMS protect the dough from staling hence

exert a preservative action .So higher air retention capacity was observed in KBr.

Chemical Leavening Agents

The interaction of water, acid, heat and chemical leavening agents (baking powders)releases CO2. The release of gas may occur in the dough prior to or during oven baking.

The agents consist of a CO2-generating source, as a rule sodium bicarbonate,

and an acid carrier, usually disodium dihydrogendiphosphate, sometimes monocalcium

phosphate [Ca(H2PO4)2]. Glucono--lactone or tartar (acidic potassium tartrate) are usedas acid carrier for phosphate-free baking powder. The phosphate-free leavening mixtures

produced on an industrial scale contain citric acid or its acidic sodium salt. In baking

powder, the two reactive constituents are blended with a filler which consists of corn,rice, wheat or tapioca starch or sometimes dried wheat flour. The filler content in

the powder is up to 30%. The role of the filler is to prevent premature release of CO2.

The market also offers baking powders flavored with vanillin or ethyl vanillin.For every 500 g of flour, baking powder should develop 2.352.85 gCO2, equivalent to

about 1.25 liters. In individual cases, NaHCO3 alone is used for some flat shelf-stable

cookies and ammonium hydrogencarbonate (NH4HCO3) for many others. Ginger andhoney cookies are leavened by NH4HCO3, mostly together with potash (K2CO3). To a

small extent, a 1:1 mixture of ammonium hydrogencarbonate and ammonium carbamate

(H2NCOONH4) is used in some countries.Both decompose above 60 C to NH3,CO2

and water.

References

1. Food processing technology Principles and Practice Second Edition P. Fellows

Director, Midway Technology and Visiting Fellow in Food Technology at Oxford

Brookes University2. Food Chemistry H.-D. Belitz W. Grosch P. Schieberle 4th revised and extended

ed.


Documents

Areation of Cereal Dough by Yeast-Lak