Abstract The aim of this study was to examine the washing effect of the positively charged emulsion produced by the combination of peanut skin extract (PSE) and benzethonium chloride (BEC) against Listeria monocytogenes and Escherichia coli O157:H7 on fresh-cut romaine lettuce. PSE and BEC showed a good washing effect regardless of pathogenic bacteria type. Specifically, the combination of 5 mg/mL PSE and 0.5 mg/mL BEC (PSE-BEC) resulted in 3.06 and 2.83 log reductions in L. monocytogenes and E. coli O157:H7 populations inoculated on romaine lettuce leaves, respectively, compared to washing with water alone. Further, the PSE-BEC treatment-induced reduction in the levels of these two pathogenic bacteria was greater than that with 0.2 mg/mL sodium hypochlorite. SEM analysis revealed a decrease in the number of bacteria and a change in cell membrane morphology on the lettuce surface following PSE-BEC treatment. Moreover, analysis of contact angle and particle characteristics (i.e. ζ–potential, particle size, and polydispersity index) of the washing solution indicated a correlation between the washing effect and the physicochemical characteristics of the PSE-BEC solution. Furthermore, washing with PSE-BEC did not change the quality of lettuce leaves during storage. These results suggest that PSE-BEC has the potential to be used as an effective washing agent for freshly cut romaine lettuce as an alternative to chlorine-based sanitizers.

中文翻译：

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花生皮提取物/苄索氯铵乳液洗涤对鲜切生菜接种单核细胞增生李斯特菌和大肠杆菌O157:H7的灭活作用

摘要 本研究的目的是检验花生皮提取物 (PSE) 和苄索氯铵 (BEC) 混合产生的带正电荷乳液对单核细胞增生李斯特菌和大肠杆菌 O157:H7 的洗涤效果，对鲜切生菜进行清洗。无论病原菌类型如何，PSE 和 BEC 均表现出良好的洗涤效果。具体而言，5 mg/mL PSE 和 0.5 mg/mL BEC (PSE-BEC) 的组合导致单核细胞增生李斯特菌和大肠杆菌 O157:H7 种群分别与长叶莴苣叶相比减少了 3.06 和 2.83 log单独用水洗。此外，PSE-BEC 处理引起的这两种病原菌水平的降低大于 0.2 mg/mL 次氯酸钠。SEM 分析显示，PSE-BEC 处理后，生菜表面的细菌数量减少，细胞膜形态发生变化。此外，对洗涤溶液的接触角和颗粒特性（即 ζ 电位、粒度和多分散指数）的分析表明洗涤效果与 PSE-BEC 溶液的物理化学特性之间存在相关性。此外，用 PSE-BEC 清洗不会改变储存期间生菜叶的质量。这些结果表明 PSE-BEC 有可能被用作新切生菜的有效清洗剂，作为氯基消毒剂的替代品。和多分散指数）表明洗涤效果与 PSE-BEC 溶液的物理化学特性之间存在相关性。此外，用 PSE-BEC 清洗不会改变储存期间生菜叶的质量。这些结果表明 PSE-BEC 有可能被用作新切生菜的有效清洗剂，作为氯基消毒剂的替代品。和多分散指数）表明洗涤效果与 PSE-BEC 溶液的物理化学特性之间存在相关性。此外，用 PSE-BEC 清洗不会改变储存期间生菜叶的质量。这些结果表明 PSE-BEC 有可能被用作新切生菜的有效清洗剂，作为氯基消毒剂的替代品。