Membrane-Disruption-Enhanced Synergistic Antimicrobial Action of Essential Oils and ε-Polylysine for Targeted Inhibition of Spoilage Yeasts in Blue Honeysuckle (Lonicera caerulea L.)

Abstract

The spoilage of blue honeysuckle during storage is mainly caused by specific dominant microorganisms, while most antimicrobial systems are developed without considering these target spoilage species. In this study, dominant spoilage yeasts were isolated from blue honeysuckle berries, and an antimicrobial system was constructed using these yeasts, along with common foodborne bacteria as target strains. The results showed that the antimicrobial system exhibited significant synergistic antimicrobial activity. Further analysis indicated that the essential oils disrupted the cell membrane structure and increased membrane permeability, thereby promoting the interaction of ε-PL with intracellular components. Multiple physiological alterations were detected after treatment, including membrane depolarization, leakage of intracellular components, accumulation of intracellular reactive oxygen species, and suppression of cellular metabolism. These observations suggested that damage to microbial cells might be synergistically induced by the composite system. Application of the system to blue honeysuckle berries effectively inhibited the growth of endogenous spoilage microorganisms and delayed quality deterioration during storage, and significantly reduced weight loss and decay rates, as well as changes in color, anthocyanin content, and vitamin C content. These results indicate that constructing antimicrobial systems based on dominant spoilage microorganisms can improve preservation efficiency and provide a useful approach for the storage of blue honeysuckle and similar fruits.