Antifungal Effect of <i>Lactiplantibacillus plantarum</i> Y48 Postbiotics Combined with Potassium Sorbate in Bread

Mycotoxigenic molds pose a threat to human health and cause economic losses in bread production. To address this issue, postbiotics have emerged as promising natural bioprotective agents due to their antifungal properties. In this study, postbiotics were obtained from Lactiplantibacillus (Lp.) plantarum Y48, Liquorilactobacillus (Lq.) hordei SK-6, and Lp. plantarum VB-29 strains and subsequently lyophilized. The functional groups of the bioactive components in these postbiotics were identified using FTIR spectroscopy. Samples extracted with different solvents were analyzed for their volatile compound profiles by GC-MS, and the results were compared using principal component analysis (PCA). The antifungal activities of postbiotics were tested. Subsequently, the antifungal activity of Lp. plantarum Y48 postbiotic was evaluated on bread contaminated with Aspergillus niger and Penicillium expansum. The postbiotic was incorporated into the bread formulation both alone and in combination with potassium sorbate, and it was also applied to the bread surface as a spray. Notably, the formulation containing 3% postbiotic + 0.1% potassium sorbate completely inhibited the growth of A. niger and P. expansum. These results indicate that the combined use of Lp. plantarum Y48 postbiotic and potassium sorbate can effectively prevent mold growth in bread and holds potential as a natural bioprotective approach in food preservation applications.