Phenolic Content in Traditionally Processed Erythrina indica L. Seeds: Antioxidant Potential and Type II Diabetes Related Functionality

The methanolic extract of Erythrina indica L. (Paltemadar) seed materials, an underutilized food legume collected from India was analyzed for antioxidant and health relevant functional properties. The methanolic extract of raw seeds contained total free phenolic content of 11.78 ± 1.17 g catechin equivalent/100 g extract DM. Encouraging levels of ferric reducing/antioxidant power (FRAP, 1213 mmol Fe[II]/mg extract), inhibition of β-carotene degradation (48.26%) and scavenging activity against DPPH (63.46%) and superoxide (44.56%) radicals were exhibited by the raw samples. Further, it also recorded 64.38% of α-amylase and 78.82% of α-glucosidase enzyme inhibition characteristics under in vitro starch digestion bioassay. Sprouting + oil-frying caused an apparent increase on the total free phenolic content and also significantly improved the antioxidant and free radical scavenging capacity of E. indica seeds, while soaking + cooking as well as open-pan roasting treatments showed diminishing effects. Moreover, inhibition of α-amylase and α- glucosidase enzyme activities was declined to 22.48 and 40.91%, respectively during sprouting + oil-frying treatment, which is more desirable for the dietary management of type II diabetic patients.