Rheology and particle size changes during idli fermentation.

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..

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Abstract

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.

Item Type:	Article
Uncontrolled Keywords:	FERMENTATION-; FERMENTED-FOODS; LEGUMES-; PARTICLES-; PHYSICAL-PROPERTIES; RHEOLOGICAL-PROPERTIES; RICE-; IDLI-; SIZE-
Subjects:	600 Technology > 08 Food technology > 18 Processed foods > 02 Fermented foods 600 Technology > 08 Food technology > 14 Physical properties > 03 Rheology
Divisions:	Food Engineering
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	05 Aug 2008 08:39
Last Modified:	03 Oct 2018 06:40
URI:	http://ir.cftri.res.in/id/eprint/7712

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