Evaluation of the antioxidant activity and identification of potential antioxidant peptides in commercially available probiotic Cheddar cheese
Wanshuang Yang
Abstract
The aim of this study was to evaluate the antioxidant activity of two commercially available probiotic Cheddar cheeses (C-1 and C-2) and to preliminarily identify potential antioxidant peptides. The results revealed that the water-soluble extract and ultrafiltration fractions from both cheeses exhibited remarkable antioxidant effects, effectively protecting H2O2-induced cells by reducing ROS and MDA levels while increasing CAT and SOD activity. Notably, the <3 kDa fraction of C-1 cheese demonstrated the highest antioxidant activity. Seven fractions with significant antioxidant activity were identified by Sephadex G-25 gel filtration analysis of the < 3 kDa fraction of C-1, and fraction V had the highest activity at approximately 80%. Furthermore, four peptides were identified from fraction Ⅴ as αs2-CN f(204–212) (AMKPWIQPK), β-CN f(177–183) (AVPYPQR), β-CN f(108–113) (EMPFPK), and β-CN f(170–176) (VLPVPQK). These peptides possessed molecular weights of 1098.622 Da, 830.458 Da, 747.374 Da, and 779.502 Da, respectively. AVPYPQR and VLPVPQK have been previously reported, while EMPFPK and AMKPWIQPK may exhibit potential antioxidant properties due to their amino acid sequence characteristics such as proline and methionine residues. Overall, these findings indicate that commercial probiotic cheddar cheeses have great potential as a natural source of antioxidants.