Determination of Changes in Amylose and Amylopectin Percentages of Cowpea and Green Gram during Storage

Abstract

Freshly harvested Samples of cowpea (Variety Dhawala and Waruni) and green gram (Variety MI-5) were collected from Research, Field Crops Research and Development Institute, Mahailluppallama. Sri Lanka. The objective of the study is to determine the change of amylose and amylopectin percentage in starches of stored Green gram and Cowpea with time and to determine the physio-chemical properties of respective starches and flours accordingly. Study was carried throughout 12 weeks in 2 week intervals starting from the day 1 after the legumes being harvested. A significant change in amylose percentages of the legumes was not resulted within the study period of 12 weeks for all 3 varieties though declining trend with weak correlation was observed. (Declines of 0.14% for Waruni, 0.13% for Dhawala and 0.18% for MI-5) but there was a significant difference among the two cowpea varieties. Highest amylose percentage was shown in cowpea variety Dhawala (35.25-35.12%) and the lowest in Cowpea variety Waruni (28.85-28.71%).