Effect of alpha-amylase addition on fermentation of idli - A popular south Indian cereal - Legume-based snack food

Idli is a fermented breakfast food widely consumed in Southern India. It is liked by people mainly due to its sensory attributes such as mouthfeel, appearance, taste and aroma. Fermentation time of the batter varies from 14 to 24 h with overnight fermentation being the most frequent time interval. Reduction in the fermentation time of the idli batter is of great commercial significance for large-scale idli production and this can be potentially achieved by addition of enzymes externally. The present study was undertaken to explore the possibility of expediting the idli batter fermentation process by adding an exogenous source of alpha-amylase enzyme. 5, 15 and 25 U per 100 g batter of amylase were added to the idli batter which was allowed to ferment. Different parameters were monitored and sensory attributes were also studied and compared with that of the control set. The fermentation time was reduced from a conventional 14 h to 8 h and the sensory attributes of the final product were also successfully maintained. (c) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.