Combination of Chitosan, Tea Polyphenols, and Nisin on the Bacterial Inhibition and Quality Maintenance of Plant-Based Meat

Plant-based meat products have gained attention in the food industry and with consumers. Plant-based meat products primarily comprise plant proteins and are rich in nutrients. However, the products are highly susceptible to bacterial contamination during storage. Biological preservatives are easily degradable alternatives to chemical preservatives and can preserve different kinds of food. In order to investigate the preservation properties of chitosan (CS), tea polyphenols (TPs), and nisin treatments on plant-based meats, the sensory evaluation, color difference, pH, TBARS, and the total plate count of E. coli, S. aureus, and Salmonella, indicators of the biological preservative-treated plant-based meat, were determined in this study. The experiment involved blank control- and biological preservative-treated samples. We found that the total microbial count exceeded the national standard provisions in the control samples stored for 14 days. The colors, tissue structures, and flavors of plant-based meat have gradually deteriorated, with the sensory score dropping from 90 to 52. The sample had a loose tissue structure and an obvious sour taste. However, the shelf life of the plant-based meat samples treated with different combinations of the biological preservatives increased compared to the shelf life of the control samples. After 56 d of storage, 1% chitosan, 2.5% tea polyphenols, and 0.04% nisin sensory reduction to 56, the total number of colonies and S. aureus were 4.91 and 2.95 lg CFU/g, approaching the national standard threshold; E. coli was 2 lg CFU/g, reaching the national standard threshold. Thus, the samples treated with 1% chitosan, 2.5% tea polyphenols, and 0.04% nisin had the longest shelf life (56 days) among all experimental groups. Hence, this study reveals that a combination of biological preservatives may be a non-toxic alternative for the efficient preservation of plant-based meat products.