Food Chemistry, Nutrition and Safety

Antioxidant peptides were successfully identified from rice bran protein hydrolysate. The alcalase hydrolysate showed a higher degree of hydrolysis (18.87 ± 0.59%) than the trypsin and pepsin hydrolysates, The hydrolysate from alcalase enzyme was then further separated by ultra filteration membrane system, was further purified using reversed-phase UFLC and subjected to matrix assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) for sequential identification of the peptide.The sequence M.LPAAPGGWLYPAK.L and R.MIMGSTSGQSGDR.L + Oxidation (M) was identified as antioxidant peptide.Using an untargeted metabolomics approach, metabolite discriminations among rice bran protein hydroxylates sections were illustrated by Venndiagram,heatmap, PCA, o-PLSDA, correlation matrices, and S-plot. UHPLC-QTOF-IMS revealed 50 metabolites including terpinoids, lipids, sugars, and amino acids. This comprehensive metabolomic report brings new insights into metabolite distribution and itspossible future implementations in food and nutraceuticals. The peptides produced by the partial hydrolysis has been evaluated for determining protein solubility, e mulsion activity index,emulsion stability index, foam capacity and foam stability,DPPH assay ,FRAP assay and ABTS Assay.Hydrolysates from rice bran behaves similar to lentil and soyabean hydrolysates. These improved functional properties of rice bran protein hydrosylates would make it use full for broad range of industrial food and pharmaceutical application.