Innovative edible coatings: Lactiplantibacillus plantarum postbiotics and chitosan as a clean-label strategy for sausage preservation

This study investigates the potential of Lactiplantibacillus plantarum -derived postbiotics combined with chitosan as an edible coating for preserving sausages. The antimicrobial, antibiofilm, and antioxidant activities of six coating formulations were tested: A (Lynch et al.), B (100%-postbiotic), C (1%-chitosan), D (0.5%-chitosan), E (1%-chitosan + 100%-postbiotic), and F (0.5%-chitosan + 100%-postbiotic). Effects on pH, moisture content, thiobarbituric acid (TBA) values, and antibacterial activity were measured during 21 days of storage at 4°C. Results showed that postbiotics produced significant inhibition zones (15 and 17 mm) against Escherichia coli and Salmonella Typhimurium and significantly inhibited biofilm formation, with inhibition levels ranging from 9% to 46% (500–1000 mg/mL). Additionally, they exhibited 32% DPPH radical scavenging activity. Coatings containing postbiotics and chitosan (samples E and F) effectively reduced changes in pH and moisture compared to the control (P<0.05). The formulation of 100% postbiotic and 1% chitosan (E) significantly inhibited lipid oxidation and maintained microbial stability during storage. Overall, postbiotic and chitosan-based edible coatings effectively reduce microbiological and chemical degradation in sausages, presenting a promising, natural alternative to traditional preservatives.