Innovative food safety strategy: Eugenol nanoemulsion with lactobacillus derived post-biotic biopolymer for biofilm inhibition on food and contact surfaces

Abstract

Foodborne pathogens such as Listeria monocytogenes and Salmonella spp. form resilient biofilms on food-contact surfaces and fresh produce, posing a significant challenge to food safety. This study is the first of its kind to investigate a postbiotic biopolymer-based eugenol nanoemulsion for biofilm control in food safety applications. The biopolymer, an exopolysaccharide (EPS) derived from Lactobacillus plantarum, was utilized as a natural emulsifier to encapsulate eugenol, enhancing its stability and antimicrobial efficacy. The Eugenol -EPS (Eu-EPS) nanoemulsion exhibited an average droplet size of 192 ± 1.89 nm and a zeta potential of −32 ± 1.90 mV, ensuring nanoscale dispersion and colloidal stability. The encapsulation efficiency was measured as 65.23 ± 0.45 %. The nanoemulsion demonstrated a bacteriostatic effect, achieving up to 3.17 log CFU/cm² biofilm reduction on stainless steel and plastic surfaces (p < 0.05). On fresh produce, it led up to a 3-log reduction of Salmonella and Escherichia. coli on tomatoes and blueberries, and a 4-log reduction in L. monocytogenes on queso fresco cheese, highlighting its potential as a natural and food-safe antimicrobial solution. By utilizing lactic acid bacteria EPS as a functional carrier for eugenol nanoemulsions, this study introduces a sustainable biofilm control strategy as an alternative to conventional chemical sanitizers in food processing environments.