Flavor strengthening Maillard-modified peptides of hydrolyzed corn protein: auxiliary bacteriostatic function on spare rib broth and its underlying mechanism

BACKGROUND: Maillard-modified peptides are renowned for their remarkable flavor-enhancing, antioxidative and bacteriostatic effects. However, the bacteriostatic mechanism and their practical applications in both flavor enhancement and preservation in actual dishes remain unclear. Addressing these issues is crucial to advancing the application of Maillard-modified peptides in food industry. RESULTS: Maillard-modified peptides were prepared using hydrolyzed corn protein, xylose and cysteine. Maillard-modified peptides (5.0 g kg⁻¹) significantly improved the spare rib broth's kokumi, meaty flavor, fatty aroma and overall acceptability. Gas chromatography-mass spectrometry and partial least squares regression analysis showed that 16 volatiles were significantly positively correlated with the sensory attributes of spare rib broth. Comprehensive analyses of sensory quality, total bacterial count and total volatile basic nitrogen indicated that the combination of Maillard-modified peptides with potassium sorbate effectively extended spare rib broth freshness to 8 days at 25 ± 1 °C. Maillard-modified peptides exhibited pronounced antimicrobial activity against Staphylococcus aureus and Escherichia coli. After 12 h of exposure to Maillard-modified peptides at twice the minimum inhibitory concentration, the extracellular protein content of S. aureus and E. coli increased by 9.69-fold and 8.36-fold compared to controls. This treatment also resulted in the near-complete destruction of cell membranes of S. aureus and E. coli. CONCLUSION: Maillard-modified peptides exhibit dual effects of enhancing flavor and bacteriostatic activity on spare rib broth. Membrane damage is an underlying mechanism for the bacteriostatic activity of Maillard-modified peptides. This study presents a novel strategy for developing natural condiments with antimicrobial properties.