Sodium hypochlorite has been used in the food industry to reduce microbial contamination in food; however, the use of sodium hypochlorite is insufficient considering the human health hazards and environmental pollution. To overcome this issue, plant-derived antimicrobial agents have been developed. In our previous study, Cudrania tricuspidata leaf extract (0.4%) was used to wash fresh vegetables for 3 min; however, Cudrania tricuspidata leaf extract was not effective in inhibiting gram-negative pathogens. Therefore, to enhance microbial decontamination by Cudrania tricuspidata leaf extract, ultraviolet-C irradiation (1.8 kJ/m²) was used in combination on spinach as a model system. After the combined treatment, the microbial count of Listeria monocytogenes, Escherichia coli O157:H7, and pre-existing bacteria on spinach were reduced by 1.94, 1.93, and 2.10 log CFU/g, respectively. The log reduction levels of the combined treatment against Listeria monocytogenes, Escherichia coli O157:H7, and pre-existing bacteria on spinach were higher than those of 200 ppm sodium hypochlorite washing (1.46, 1.26, and 1.44 log reduction). Moreover, an increased amount of cellular constituents was released from the pathogens due to the combined treatment compared with the single treatment of Cudrania tricuspidata leaf extract washing or ultraviolet-C irradiation. The distorted and ruptured pathogens after the combined treatment were observed via scanning electron microscopy. Furthermore, combined treatment did not affect the color, texture, and bioactive compounds in spinach. These results suggest that combination of Cudrania tricuspidata leaf extract washing and ultraviolet-C irradiation used in the present study can be an effective method to replace sodium hypochlorite washing.

次氯酸钠已用于食品工业，以减少食品中的微生物污染；然而，考虑到对人类健康的危害和环境污染，次氯酸钠的使用不足。为了克服这个问题，已经开发了植物来源的抗微生物剂。在我们先前的研究中，使用Cu木叶提取物（0.4％）清洗新鲜蔬菜3分钟；然而，Cu木叶提取物不能有效抑制革兰氏阴性病原体。因此，为了增强Cu草叶提取物对微生物的净化作用，在菠菜上结合使用UV-C辐照（1.8 kJ / m ²）作为模型系统。综合治疗后，微生物计数单核细胞增生李斯特菌，大肠杆菌O157：H7和菠菜上已存在的细菌分别降低了1.94、1.93和2.10 log CFU / g。对抗菠菜单核细胞增生李斯特菌，大肠杆菌O157：H7和先前存在的细菌的联合处理的对数减少水平高于200 ppm次氯酸钠洗涤的对数减少水平（1.46、1.26和1.44对数减少）。此外，与单一处理of草相比，通过联合处理从病原体中释放出更多的细胞成分叶提取物洗涤或紫外线照射。通过扫描电子显微镜观察联合处理后的变形和破裂的病原体。此外，联合处理不会影响菠菜的颜色，质地和生物活性化合物。这些结果表明，本研究中使用的Cu草叶提取物洗涤和紫外线-C辐照相结合可以成为替代次氯酸钠洗涤的有效方法。