Vol. 8, Issue 6 (2019)

Author(s):
Rozeena Parvez, Kunal Singh, Vyakhaya Yadav and Lovy Singh

Abstract:
Flavonoid is an important polyphenol contributing to antioxidant activity of food. Total Flavonoid Content (TFC) of four cultivars of cowpea (Gomati, EC 4216, BL-1, and BL-2) were determined in this study. TFC was analyzed using spectrophotometer in terms of mg quercetin equivalent per gram. The effect of selected thermal processing (boiling, roasting, microwave, autoclave and extrusion) and bioprocessing (germination and fermentation) on the total flavonoid content of two variety of cowpea (Gomati and EC 4216) were studied. All treatments conducted in this study caused a significant (p<0.05) reduction in the analyzed flavonoid content in all cultivars of cowpea except extrusion. Among all the studied unprocessed cowpea cultivars BL-1 showed maximum flavonoid content (1.18 mg QE/gram) followed by Gomati (1.05 mg QE/gram), EC-4216 (1.02 mg QE/gram) and BL-2 (0.843 mg QE/gram). In thermal treatments, autoclaving caused highest reduction (83%-55%) in TFC followed by boiling (48%-43%), microwave (35%-21%) and roasting (33%-25%), while extrusion process enhances the TFC by 10% -13%. While in bioprocessing, germination causes maximum reduction (75%-38%) in TFC which increased with time (24hr, 48 hr, 72 hr), while fermentation reduces the flavonoid content by 67% - 43% which also increased with time (16hr, 24hr, 36hr). The correlation between Lab value and TFC was established which showed TFC of all cowpea cultivars were negatively correlated with ‘a’ value (-0.9440) and ‘b’ value (-0.924).