This paper reviews the effects of domestic and foreign influences on the substance metabolism pathways and the flavor and flora of LAB in fermented meat products to provide a new theoretical basis for developing new products for the industrial application of lactic acid bacteria (LAB) in fermented meat products. LAB are extensively used among commonly fermented ingredients, such as fermented meat products and yogurt. As fermenting agents, LAB metabolize proteins, lipids, and glycogen in meat products through their enzyme system, which affects the tricarboxylic acid cycle, fatty acid metabolism, amino acid decomposition, and other metabolic processes, and decompose biological macromolecules into small molecules, adding a special flavor with a certain functionality to the final product. Metabolites of LAB in the fermentation process also exert nitrite degradation, as well as antibacterial and antioxidant functions, which improve the physical and chemical qualities of fermented meat products. While fermenting meat products, LAB not only add unique flavor substances to the products, but also improve the safety profile of fermented foods.

Protein, which is the main component of meat, is degraded and oxidized during meat fermentation. During fermentation, macromolecular proteins are degraded into small peptides and free amino acids, and oxidation leads to amino acid side chain modification, molecular crosslinking polymerization, and peptide chain cleavage. At different metabolic levels, these reactions may affect the protein structure and the color, tenderness, flavor, and edible value of fermented meat products. Lactic acid bacteria are currently a research hotspot for application in the fermented meat industry. Its growth metabolism and derivative metabolites formed during the fermentation of meat products regulate protein degradation and oxidation to a certain extent and improve product quality. Therefore, this paper mainly reviews the changes occurring in proteins in fermented meat products and their effects on the quality of the products. Referring to studies on the effects of lactic acid bacteria on protein degradation and oxidation from all over the world, this review aims to provide a relevant reference for improving the quality of fermented meat products.

The aim of the present work was to investigate the effects of feeding regimens (pasture vs. mixed diet) on meat quality, fatty acids, volatile compounds, and antioxidant properties in lamb meat. In total, 24 lambs were allotted into two feeding regimens at 10.23 kg live weight. Lambs were fed on pasture grass (PG group, n = 12) or mixed diet (M group, n = 12). Longissimus thoracis (LT) muscle samples from the M group had a higher intramuscular fat (IMF) (p < 0.05), pH_45minvalue (p < 0.01), and ash (p < 0.05) than the PG group. In contrast, the shear force (p < 0.05), L*(p < 0.05), and b* (p < 0.001) in M group were lower than in PG group. Analyses indicated that PG group contained higher linolenic acid (C18:3n3) and docosatrienoic acid (C22:3n6) (p < 0.05) than the M group. Major volatile compounds in the muscles included hexanal, heptanal, nonanal, octanal, 1‐pentanol, 1‐hexanol, 1‐octen‐3‐ol, and 2,3‐octanedione. The levels of hexanal, nonanal, and 2,3‐octanedione were significantly lower in PG lamb muscle (p < 0.01). In contrast, 1‐pentanol and 1‐hexanol levels were higher in M lamb muscle (p < 0.01). Muscle from PG lamb exhibited higher catalase (CAT) and glutathione peroxidase (GPx) activity (p < 0.05). PG muscle also contained a higher radical‐scavenging ability (RSA; p < 0.001) and cupric‐reducing antioxidant capacity (CUPRAC; p < 0.05). Overall, the improved antioxidant status in PG muscle inhibited lipid peroxidation (aldehydes and ketones), thereby improving the meat quality.

This study investigated the effects of probiotics on growth performance, meat quality, muscle fiber characteristics, volatile compounds, and antioxidant capacity in lambs. A total of 24 Sunit lambs were randomly allocated into two groups, each consisting of three replicates of four lambs. Throughout the experiment period, the lambs were fed with based diet (CON) and 10 g probiotics/d supplemented diet (PRO). Compared with the CON group, the number of lactic acid bacteria in fecal samples of PRO group was significantly increased (p < .05) and the coliforms were significantly decreased (p < .05). Dietary probiotics supplementation decreased pH_24h, L*, and shear force (p < .05). The muscle fibers were switched from type IIB to type I, with a decrease in the mean cross‐sectional area (CSA) (p < .05) of longissimus thoracis (LT) muscle. Also, probiotics altered the composition of meat volatile flavor compounds, such as nonanal, undecanal, 1‐pentanol, 1‐hexanol, and 2,3‐octanedione. In addition, probiotics increased the total antioxidative capacity (T‐AOC) and catalase (CAT) activity of LT muscle, while it decreased superoxide dismutase (SOD) activity (p < .05). Overall, these results indicated that probiotics could be used as an effective feed additive by improving meat tenderness and flavor.

This study was conducted to evaluate the effects of inoculation with different mixed starter culture combinations on microbial counts, physico‐chemical properties, and proteolytic and lipolytic properties of dry fermented mutton sausages during fermentation and ripening. Four different batches of mutton sausages were manufactured: CO batch, no starter cultures, used as control; LB batch with Lactobacillus sakei; LS batch with L. sakei + Staphylococcus xylosus; and LSS batch with L. sakei + S. xylosus + Staphylococcus carnosus. The results showed that adding starter culture caused Lactobacillus and Staphylococcus to become dominant bacteria and reduced the Enterobacteriaceae count in the inoculated sausages. The mixed starter cultures (LS & LSS) accelerated acidification and reduced water activity and lipid oxidation. Statistical analysis revealed that the use of mixed starter cultures, especially the combination L. sakei + S. xylosus + S. carnosus, contributed to proteolysis and lipolysis, increasing total free amino acids and polyunsaturated fatty acids. The above results demonstrate that the use of mixed starter cultures contributes to improving the composition of free amino acids and free fatty acids as well as the hygienic quality of dry fermented mutton sausages.