In Vitro Antibacterial Activity of Polyphenols From <i>Yucca</i> spp. Flowers Against Bacteria Isolated From Decaying Fruits

ABSTRACT Postharvest decay is a critical issue in the food industry, emphasizing the need for effective microorganism control to extend the shelf life of fruits and vegetables. Biological methods, seen as safer alternatives, have gained attention. While polyphenols, bioactive compounds found in plants, exhibit antimicrobial properties against foodborne pathogens, their effectiveness against decay‐causing microorganisms remains poorly explored. This study aimed to evaluate the antimicrobial impact of semi purified flower polyphenols from three Yucca species ( Y. carnerosana, Y. filifera, Y. treculeana ) on bacteria associated with fruit decay and their implication in membrane integrity. Four decay‐associated bacteria were isolated ( Bacillus sp., Enterobacter hormaechei, Klebsiella pneumoniae , and Microbacterium sp.) and identified by 16S rRNA gene sequencing. Antimicrobial assays demonstrated that Microbacterium sp. was the most sensitive strain, showing 60%–100% growth inhibition at 500 ppm of the ethanolic Y. filifera polyphenolic extract. The same extract exhibited the highest activity against Bacillus sp., with 68% inhibition. In contrast, K. pneumoniae and E. hormaechei were more resistant, with only 7.7% and 19.1% inhibition, respectively. Furthermore, membrane permeability assays indicated a 51.45% increase in relative conductivity in Microbacterium sp. after exposure to the polyphenolic extract. This study demonstrated that ethanol‐extracted and semipurified Yucca polyphenols exhibit antimicrobial potential against fruit‐decay bacteria, though their efficacy varies depending on bacterial characteristics. These findings suggest the potential application of Yucca ‐derived polyphenols as natural antimicrobials in postharvest treatments aimed at extending the shelf life of perishable fruits.