Effect of Kidney bean (Phaseolus vulgaris) on textural, sensorial and nutritional quality of idli – a cereal and legume based fermented food

Abstract

Idli is a traditional breakfast food widely consumed in Southern parts of India. Idli is famous for its soft spongy texture, desirable sour taste and characteristic aroma. It is basically prepared from rice and black gram dhal. Black gram dhal has a major role in the preparation of idli as a source of microorganisms and as fermenting substrate. The aim of the present study was to improve the protein content and textural parameters of idli by substitution of kidney bean in idli batter. Kidney beans (Phaseolus vulgaris) are a key food source for humans because the seed is low in fat and are a very good source of folate and fibre. For many people in the world, the seed is an important and economical source of high dietary protein. This is because kidney beans contain up to 20–30% protein on a dry weight basis and have been shown to have good amino acid composition which makes the seed a good candidate for the formulation of nutritious foods. A base blend of 300g of rice kept as constant and 118g of black gram dhal was replaced with kidney beans at the ratio of 30%, 40% and 50%. The prepared batter is kept for fermentation for 8 hours at 30ºC. The batter was poured in idli mould and steam cooked in idli steamer for 15min. The formulated idlis were evaluated for their physical, textural and sensory characteristics. Based on the overall results of both textural and sensory parameters ,the present data suggest that kidney bean could be substituted up to a level of 40% replacement of black gram dhal in idli to develop nutritious ,organoleptically acceptable breakfast food.