Abstract
Lactic acid bacteria metabolites can be used as a clean-label strategy for meat products due to their "natural" and antibacterial properties. In this study, the feasibility of using cell-free supernatant of Lactiplantibacillus plantarum 90 (LCFS) as a natural antibacterial agent in ground beef was investigated. The sensitivity of LCFS to pH, heat and protease, as well as the changes of enzyme activities of alkaline phosphatase (AKP) and Na(+)/K(+)-ATP together with the morphology of indicator bacteria after LCFS treatment, were analyzed to further explore the antibacterial mechanism of LCFS. The results showed that the addition of 0.5% LCFS inhibited the growth of microorganisms in the ground beef gel and extended its shelf-life without affecting the pH, cooking loss, color and texture characteristics of the product. In addition, the antibacterial effect of LCFS was the result of the interaction of organic acids and protein antibacterial substances in destroying cell structures (cell membrane, etc.) to achieve the purpose of bacteriostasis. This study provides a theoretical basis for the application of LCFS in meat products and a new clean-label strategy for the food industry.