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Rheology and particle size changes during idli fermentation.

IR@CFTRI: CSIR-Central Food Technological Research Institute, Mysore


Field	Value

Relation	http://ir.cftri.com/7712/ JFE-28-00

Title	Rheology and particle size changes during idli fermentation.

Creator	Nagaraju, V. D. Manohar, B.

Subject	02 Fermented foods 03 Rheology

Description	Changes in rheological properties and particle size during fermentation of idli (a fermented food made from rice and black gram) were investigated; dimensional parameters of batter formed using a specially developed automated idli processing unit and the effects of rice:black gram ratio (2:1, 3:1 and 4:1) on idli quality were also studied. Shear stress and shear rate values obtained for different idli batters during fermentation (23 h at ambient temp.) showed good agreement with the power law model with yield stress. Yield stress values were in the range 13-43 Pa and reached a max. value at 7 h of fermentation. Flow behaviour indices were in the range 0.287-0.605, indicating strong non-Newtonian behaviour. Consistency index was observed to increase with increasing rice:black gram ratio at all fermentation times. Particle sizes in batters ranged up to 2000 mum; approx. 80% of particles were <782 mum and mean particle size for all batter types as a function of fermentation time ranged from 500 to 600 mum. No defined trend in particle size with respect to fermentation time and rice:black gram ratio was observed; however, a small increase in mean particle size occured between 4 and 13 h of fermentation. Height of batters showed little variation between batter types while diam. decreased with increasing ratio rice:black gram ratio. A rapid vol. increase was observed in batters after 4 h fermentation; rate of vol. increase progressed steadily until approx. 13 h and then slowed down.

Date	2000

Type	Article PeerReviewed

Format	application/pdf

Language	en

Identifier	http://ir.cftri.com/7712/1/Journal_of_Food_Engineering_43_%282000%29_167-171.pdf Nagaraju, V. D. and Manohar, B. (2000) Rheology and particle size changes during idli fermentation. Journal of Food Engineering, 43 (3). 167-171, 10 ref..