关键词: 微酸性电解水；鲜切苦菊；分离鉴定；杀菌活性

Abstract: To control the spoilage of fresh-cut chicory caused by microbial contamination of cuts, this study isolated and identified spoilage bacteria from fresh-cut chicory using 16S rRNA gene sequencing and evaluated the bactericidal activity and mechanism of slightly acidic electrolyzed water (SAEW). Five dominant spoilage strains were isolated, including Acinetobacter, Pseudomonas, Serratia, Pectobacterium, and Pantoea agglomerans. After treatment with 175 mg/L SAEW, it was found that the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and half-maximal effective concentration (EC50) of SAEW against these five spoilage bacteria were 43.75–175, 87.5–175, and 28.52–99.54 mg/L, respectively. The results demonstrated that 175 mg/L SAEW exhibited antibacterial effects against all five spoilage bacteria while significantly delaying the decline of ascorbic acid and inhibiting the accumulation of malondialdehyde (MDA). Further analysis revealed that treatment with 175 mg/L SAEW disrupted the cellular morphology and membrane integrity of the spoilage bacteria, causing the cellular surface to become sunken, wrinkled and damaged and leading to the leakage of intracellular nucleic acids and proteins. These findings suggest that SAEW likely exerts its bactericidal effect by damaging the cell membrane structure, thereby resulting in the leakage of intracellular contents.

Key words: slightly acidic electrolytic water; fresh-cut chicory; separation and identification; bactericidal activity