In this study, the antioxidant potential of peptide fractions isolated from the Tra catfish (Pangasius hypophthalmus) by-product-derived hydrolysate using ultrafiltration centrifugal devices with 3 distinct molecular-weight cutoffs (MWCOs) of 5KDa, 10KDa, and 30KDa was investigated. Firstly, the chemical composition of the Tra catfish byproducts was analyzed. | TẠP CHÍ PHÁT TRIỂN KH&CN, TẬP 20, SỐ K7-2017 35 Investigation of antioxidant capacity of peptide fractions from the Tra catfish by-product-derived proteolysate using Flavourzyme® 500 mg Tam Dinh-Le Vo, Cuong Vi Tran Abstract — In this study, the antioxidant potential of peptide fractions isolated from the Tra catfish (Pangasius hypophthalmus) by-product-derived hydrolysate using ultrafiltration centrifugal devices with 3 distinct molecular-weight cutoffs (MWCOs) of 5KDa, 10KDa, and 30KDa was investigated. Firstly, the chemical composition of the Tra catfish byproducts was analyzed. The result showed that the Tra catfish by-products contained moisture, crude protein, crude lipid and ash (on dry weight basis). Secondly, the effects of enzyme content, hydrolysis time on the antioxidant activity of the hydrolysate were studied using DPPH• (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method (DPPH• SM), and FRAP (ferric reducing antioxidant potential) method. Flavourzyme® 500 MG was used for hydrolysis. The result revealed that the antioxidant activity of the proteolysate reached the peak when the hydrolysis time was 3h, enzyme/substrate (E/S) ratio was 25 U/g protein, hydrolysis temperature was 500C, pH was 7, and the degree of hydrolysis (DH) of the hydrolysate reached . Next, the proteolysate was further fractionated using MWCOs of 5KDa, 10KDa, and 30KDa and the peptide fractions were investigated for their antioxidant activity. The result showed that the <5KDa fraction showed strongest antioxidant activity with the 50% DPPH• inhibition concentration (IC50) of ± μg/mL and FRAP value of ± μM Trolox equivalent. Manuscript Received on December 06th, 2016, Manuscript Revised February 17th, 2017. This research is funded by Ho Chi Minh City University of Technology-VNU-HCM, under grant number T-KTHH-201637. Tam Dinh-Le Vo, Cuong Vi Tran - Faculty of Chemical Engineering, Ho Chi Minh City Univeristy of Technology .
