Lactobacillus casei 1.0351 as an adjunct culture in Cheddar cheese: Modulation of bioactive peptide release and...

This study investigated the effect of adding Lactobacillus casei 1.0351 as an auxiliary strain on the release of antioxidant peptides in Cheddar cheese during a 32-week maturation period. Compared with the control group, the addition of L.casei 1.0351 resulted in higher protein hydrolysis and antioxidant activity in the cheese, with the L.casei group reaching a significant peak at week 28. Furthermore, peptide fractions with a molecular weight of less than 3 kDa exhibited the highest antioxidant activity. Compared with the control group, the L.casei group had a greater number of cleavage sites; the sequenced peptide fragments were mainly derived from α_S1-casein and β-casein, and were predominantly short-chain peptides (<20 amino acids). Six antioxidant peptides with 100% homology were identified in cheese supplemented with L.casei 1.0351: α_S1-CN f(90-92) (RYL), α_S1-CN f(91-94) (YLGY), β-CN f(193-196) (YQEP), β-CN f(169-176) (KVLPVPQK), β-CN f(59-68) (VYPFPGPIPN), and β-CN f(78-91) (TQTPVVVVPPFLQPE). Microbiome analysis revealed that L.casei 1.0351 reshaped the microbial community, increasing the abundance of the Lactococcus, suggesting that microbial community succession plays a key role in shaping the peptide profile. Overall, L. casei 1.0351 promotes the hydrolysis of casein and the formation of bioactive peptides such as antioxidant peptides, providing a theoretical basis for the development of functional cheese products.