Study on Dehydration of Fermented Idli Batter to Increase its Shelf Life

8/16/2019 Study on Dehydration of Fermented Idli Batter to Increase its Shelf Life

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A Study on Dehydration of Fermente

Batter to Increase its Shelf Life

Department of Agricultural and Food Engineering

Indian Institute of Technology Kharagpur

By

Sathya Uma Lashmi K

1!A"##$%&


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'()ecti*es

•

To study the increase in the shelf life of fermented adehydrated idli (atter under non+refrigerated conditi

• To study the ,uality changes in idli (atter

+ (efore and after processing -dehydration.

+ /ith and /ithout addition of lea*ening agents


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0ethodology

Preparation of idlibatter

Allow fermentationfor 12hr

Development ocurve

Water activity on idli battevarious moi

content

Develop batter withstable moisture

content by

dehydration

Test the batter forquality (fresh and

developedPhysical and chemical

Testing of idli (freshand developed

batter!ensory evaluation

"esults


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D$2I3" 4U$5E• Preliminary studies to form drying curve:

– The appro6imate drying time re,uired for temperatures of !%7 andthicness of &mm8 !mm8 1%mm and 1!mm9

THICKNESS OFIDLI BATTER

TEMPERATURE USED FOR DEHYDRATI(high or slow)

$%&' %&'

2mm )ery fast )ery fast

$mm *oderate *oderate

1%mm )ery slow )ery slow

1$mm )ery slow )ery slow


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:ATE$ A4TI5IT2 A3AL2SIS

– Ta(ulation sho/s the /ater acti*ity *alue of idli (atter for *ariouscontent

– Testing /as done on A,uala( digital /ater acti*ity meter9

Moistr! Co"t!"t #$t!r A%ti&it'

* +

, +

- +

. //0

0 /1-

+ 111


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Physio+chemical parameters

• ,ul- density

• p.

• )iscosity

• 'olour

•

Ash content• Protein

• Titrable acidity


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Bul density

S$23l!

Pro3ortio"

A

/01 %#%

#01 %3/

,

/01 121%

#01 12/3

• !amples dehydrated (, were made with same moistu

content as fresh batter (A by adding required amounwater


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p<

S$23l!Pro3ortio

" 3H

A

/01 /

#01 /$

,

/01 #%%

#01 #%%

1%4 concentration of the sample was made and the was found using p. meter

pH meter


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5iscosity

S$23l!

Pro3ortio"

S3i"4l! RPM

5is%osit' (C!"tiPois!)

A /01 !15 1% 2#$

!15 % #%5

!15 1%% 2#$

#01 !15 1% 2#2

!15 % #%1

!15 1%% 2#1

, /01 !15 1% 2#/5

!15 % #%$

!15 1%% 2#/

#01 !15 1% 2#2

!15 % #%/

Brookfield V


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4olour test

Sample Proportion L*

A /01 5%3$ 6

%1$#01 5#/$ 6

%%$B /01 5#$%$ 6

%%%$#01 5#3% 6

%%1%

Colour Sp

7 8 + ,rightness

•The ma6imum for L is 1%% /hich /ould (e a perfect reflectin

•The minimum for L /ould (e ?ero8 /hich /ould (e (lac9


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Total ash test

Sample Proportion Dry matterg! "sh o#tained g! "sh $!

A

@1 19#;; %9%%= %9&1#

@1 19#;= %9%%! %9&%;

B

@1 !911> %9%1&! %9&=

@1 9;>1= %9%1&% %9&!%!

MUFFL


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Titra(le Acidity test

Sample ProportionBatter

ml! %itre Valueml! "cidity $!

A

@1 1% 19& 19%=%>#

@1 1% 19% %9>%%=%

B

@1 1% 191 %9>>%==

@1 1% %9> %9=1%;&

• 1% concentration solution /as made and titration done

The slight *ariation in p< gets )ustified (y the slight decrease in titra(

the processed sample compared /ith the control9


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Crotein

•The protein test indicates that around >! of the protein is preser*ed

e*en after processing9

Sample Proportion Protein$!

A

@1 1&9

@1 1%9#

B

@1 119!

@1 1%91


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Sensory E*aluation of Idli Crepare

Idlis /ere prepared and gi*en to # mem(ers for sensory e*alua

3o side dish /as gi*en9 The properties tested are

• 4olour

• Te6ture

• Aroma

• 0outh feel

And the o*erall acceptance of idli


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• The ID no of idli and its sample composition@

1 idlis made from idli (atter dehydrated #% 4 /ithout

⁰

agent-@1 ratio.

& idlis made from idli (atter dehydrated #% 4 /ith lea⁰

agent -@1 ratio.

+ idlis made from commercial ready to coo idli po/der

idlis made from idli (atter dehydrated #% 4 /ith lea⁰agent -@1.

! idlis made from idli (atter dehydrated #% 4 /ithout⁰

agent -@1.


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SE3S'$2 A44ECTA34E 'F IDLI C$EC

• The ta(ulation sho/s a*erage of 1% points scale considering 1%

points for the idli made from fresh (atter9

&D 'o Colour Smell %e(ture )outh feel verall "ccepta

1 5// 2$ 1 5 3$

2 5$ 2// 5 $ 5

/ // 2$ 3$ $ 3$

# 5 2$ 5$ // 5$

$ 5$ 2// 1 5$ 3


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Chysio+ chemical parameters of the (est

P$r$2!t!rs *6C D!h'4r$t!4 s$23l

,ul- density

Ash content %2# 4 of dry mass

p. #

Titrable Acidity % 4 of lactic acid

Protein 11$ 4 of dry mass

'olour (78 5#$1 ( a8 +%$ (b8 3/

)iscosity 2#/5 cP (!15 spindle91%"P*


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4onclusion

• :ut of all the tests done on idli batter9 the onproperty which varied signi;cantly was the bdensity This could be overcome by adding pelimits of ba-ing soda and allowed for leaveni

• All the other tests yield positive results and h

doesn


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Future scope in the study

• The quality changes and increase in shelf lifalso be studied with reference to di>erent pand storage conditions

• The future scope in the pro?ect includes idenma=imum temperature suitable for dehydra

time required• @or commercialiation9 optimied thic-ness

temperature relationship has to be developecommercialie the pro?ect


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Than 2ouGG

Documents

Study on Dehydration of Fermented Idli Batter to Increase its Shelf Life