Isolation and identification of MBC peptides after gastrointestinal digestion
The gel filtration chromatography was used for the fractionation of MBC intestinal digest. Two fractions (fractions A and B) were obtained from Sephadex G-50 column (Fig. 1A) and their antioxidant activity was evaluated. Since natural antioxidants are characterised by complex reactivity and different mechanisms of action, the antioxidant capacity of food and food extracts cannot be assessed by using a single method (Schlesier, Harwat, Bohm, & Bitsch, 2002). Then, two different spectrophotometric assays, DPPH and FRAP tests, were executed, and antioxidant activities were expressed as trolox equivalents (TEs). The sample ability to scavenge free radicals is indicated by the decrease in DPPH absorption, while the FRAP test evaluates the reducing power of sample constituents.