Effects of Lactiplantibacillus plantarum and Staphylococcus simulans fermentation on Maillard reaction and flavor characteristics in a myofibrillar protein-glucose reaction system.

The Maillard reaction is one of the key pathways for flavor formation during the thermal processing of fermented sausages. This study used a myofibrillar protein-glucose model system mimicking fermented sausages to investigate the effects of Lactiplantibacillus plantarum (LP), Staphylococcus simulans (SS), and their co-culture (LS) on the Maillard reaction and flavor characteristics. Owing to the superior proteolytic and carbohydrate metabolic capacities of L. plantarum, the LP and LS groups exhibited higher free amino acid levels (LP: 107.61 mg/L; LS: 120.69 mg/L), particularly flavor-active ones such as glutamic acid (LP: 24.86 mg/L; LS: 28.31 mg/L) and alanine (LP: 12.52 mg/L; LS: 16.10 mg/L), and lower glucose content (LP: 25.44 mg/mL; LS: 23.83 mg/mL) compared to SS group. Post-heating, the browning intensity in the LP group increased by 54.58%, and the glucose consumption rates of LP (19.98%) and LS (17.31%) groups exceeded those of non-inoculated (5.35%) and SS (9.22%) groups. Volatile compounds analysis revealed that the LP and LS groups were richer in pyrazines and thiazoles, with LP group showing higher levels of 2-methyl-3-furanthiol (a meaty aroma marker). Electronic tongue detection indicated that the LS group had the highest umami intensity after heating. The results indicate that L. plantarum is a key strain for optimizing the Maillard reaction and flavor quality during the thermal processing of fermented sausages.