Xue Jingyi, Luo Yaguang, Li Beifang, Wang Xinhao, Xiao Zhenlei, Luo Yangchao
Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, United States.
U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Food Quality and Environmental Microbial and Food Safety Laboratories, Beltsville, MD 20705, United States.
Int J Biol Macromol. 2022 Jun 1;209(Pt A):1188-1196. doi: 10.1016/j.ijbiomac.2022.04.101. Epub 2022 Apr 19.
In this study, thymol-loaded hydrophobically modified phytoglycogen/zein nanocomplexes with a particle size around 100 nm were developed for improving microbial safety of fresh produce. The antimicrobial activities, including the determination of minimum inhibitory and bactericidal concentration, growth kinetic curves, and inhibition zone of the nanocomplexes against foodborne pathogens (Listeria monocytogenes, Salmonella enteritidis, and Escherichia coli) were evaluated. The results showed that the antimicrobial activities of the nanocomplexes were significantly stronger than that of free thymol control (without encapsulation), and the antimicrobial efficacy remained unchanged after storage at 4 °C for 60 days. The morphological results from atomic force microscope revealed that small micellar blebs were formed at the surface of bacteria after treatment with nanocomplexes and the gradual disappearance of the cell boundary indicated the occurrence of cytolysis. The potential applications of this nanocomplex as disinfectant agent in wash water were evaluated on different types of fresh produce (lettuce, cantaloupe, and strawberries). Notably, the nanocomplexes also demonstrated efficacy in biofilm removal. Findings from this study clearly demonstrated that the thymol-loaded nanocomplexes hold promising potential for the disinfection of fresh produce to improve their microbial safety and quality.
在本研究中，开发了粒径约为100纳米、负载百里香酚的疏水改性植物糖原/玉米醇溶蛋白纳米复合物，以提高新鲜农产品的微生物安全性。评估了该纳米复合物对食源性病原体（单核细胞增生李斯特菌、肠炎沙门氏菌和大肠杆菌）的抗菌活性，包括最低抑菌浓度和杀菌浓度的测定、生长动力学曲线以及抑菌圈。结果表明，纳米复合物的抗菌活性明显强于游离百里香酚对照（未包封），并且在4℃储存60天后抗菌效果保持不变。原子力显微镜的形态学结果显示，用纳米复合物处理后，细菌表面形成了小的胶束泡，细胞边界逐渐消失表明发生了细胞溶解。在不同类型的新鲜农产品（生菜、哈密瓜和草莓）上评估了这种纳米复合物作为洗涤水中消毒剂的潜在应用。值得注意的是，纳米复合物在生物膜去除方面也显示出效果。本研究结果清楚地表明，负载百里香酚的纳米复合物在新鲜农产品消毒以提高其微生物安全性和质量方面具有广阔的应用前景。
