Simple cooking and in vitro gastrointestinal digestion improves antioxidant activity of legume seed flour extracts

Abstract

Antioxidant activities and phenolic contents were studied in methanolic and water extracts of non-processed, cooked and in vitro enzymatically digested seed flour. Antioxidant activities of total protein hydrolysates and small peptide fractions (MW<3kDa and MW<3kDa) isolated from seed were also determined. Study showed that cooking and enzymatic digestion strongly enhanced release of phenolic compounds. Scavenging activity against 2,2-diphenyl-1-picryhydrazyl radical (DPPH•), hydroxyl radical and hydrogen peroxide were also increased. Protein hydrolysates especially MW<3kDa fraction possess significant antioxidative potential. Taken together our findings indicate that in methanolic and water extracts of cooked and digested seed flour small peptide fraction, beside phenolic compounds, can also significantly contribute to free radical and hydrogen peroxide scavenging activity.