Proteolytic lactic acid bacteria from multiple sources enhance proteolysis and flavor formation in a beef sarcoplasmic protein model system

This study aimed to isolate proteolytic lactic acid bacteria (LAB) from traditional fermented foods and investigate their effects on protein degradation and flavor formation in a sarcoplasmic protein model using GC-MS and amino acid analysis. Three proteolytic strains isolated from dry-aged beef, kimchi, and rice wine were identified as Lacticaseibacillus plantarum N3 ,Lacticaseibacillus paracasei L1, and Lacticaseibacillus paracasei J2. Moreover, the strain L1 exhibited the strongest proteolytic activity, yielding 7.78 and 7.73 mg/mL TCA-soluble peptides, and the highest free amino acids in a sarcoplasmic protein model system. GC-MS further revealed that the N3:L1:J2 consortium produced the most abundant volatile profile, which was characterized by key flavor compounds including phenylethanol, tert-butyl butyrate, and methyl palmitate. These findings provide theoretical insights into the proteolytic potential of these strains, suggesting their potential as candidates for the development of tailored LAB starter cultures to enhance proteolysis and flavor formation in fermented meat products.