Antioxidant activity of different mungbean genotypes in relation to phenolic acids, flavonoids and seed coat colour

Abstract

The diversity of mungbean in terms of phenolic acid, flavonoids and antioxidants was studied using thirty mungbean genotypes. Significant (P<0.05) differences were found in the contents of both bound and free phenolic acids e.g. syringic acid, p-coumaric acid, caffeic acid and ferrulic acids, comprising about 90% of total phenolic acids. The wild accession V. sylvestris recorded maximum free phenolic caffeic acid in seeds. Antioxidant activity in seed determined based on radical scavenging capacity revealed. a range of antioxidant activity with maximum >30 µmol g^-1 recorded in three wild accessions V. sylvestris, V. umbellata and V.trilobata and lowest in ML 818 (28.13 µmol g^-1) using DPPH method. However, with ABTS method, minimum activity was observed in DGGV 2 . Flavonoids and phenolic acids both act as antioxidant in mungbean and thus higher amount enhances the nutrive value of mungbean. The results showed that total flavonoids content (TFC) and and total phenolic acid (TPC) were significantly (P<0.001) correlated with antioxidant activities with correlation coefficients of 0.875 and 0.708. suggesting these mungbean cultivars are rich in balanced nutrients and should be considered as potential sources of natural antioxidants. It was observed that dark coloured seed coat genotype or yellow seed contained higher antioxidant activity than normal green seeds of mungbean . The dull green or pale brownish mung wild accession Vigna umbellata had the highest value of total flavonoid (TFC) and total phenolic acid (TPC) and exhibited highest antioxidant activity followed by yellow sona mung. The results indicated that seeds of some of the wild accessions and landraces are very nutrient dense with high antioxidant activities which could be explored for developing superior mungbean varieties.