Department of Food and Nutrition, Chung-Ang University, 4726, Seodong-daero, Anseong-si, Gyeonggi-do, Republic of Korea.
Department of Food and Nutrition, Chung-Ang University, 4726, Seodong-daero, Anseong-si, Gyeonggi-do, Republic of Korea.
Food Microbiol. 2020 Apr;86:103314. doi: 10.1016/j.fm.2019.103314. Epub 2019 Aug 29.
The aim of this study was to investigate the antibacterial effect of 460-470 nm light-emitting diode (LED) illumination against pathogens and spoilage bacteria on the surface of agar media and packaged sliced cheese. LED illumination highly inhibited the growth of Listeria monocytogenes and Pseudomonas fluorescens on agar media covered with oriented polypropylene (OPP) film (thickness, 0.03 mm). When sliced cheeses inoculated with L. monocytogenes or P. fluorescens and packaged with OPP film were illuminated by an LED at 4 or 25 °C, reduction levels of L. monocytogenes and P. fluorescens on packaged slice cheese were higher at 4 °C than at 25 °C. There were no significant differences in color between non-illuminated and illuminated sliced cheese after storage for 7 d at 4 °C. LED illumination at 4 °C for 4 d caused cellular injury of L. monocytogenes and P. fluorescens related to RNA, protein, and peptidoglycan metabolism, and a disruption of the cell membrane and loss of cytoplasmic components were observed from TEM results. These results suggest that LED illumination, in combination with refrigeration temperatures, may be applied to extend the shelf-life of packaged slice cheese and minimize the risk of foodborne disease, without causing color deterioration.
本研究旨在探讨 460-470nm 发光二极管（LED）照射对琼脂培养基和包装切片奶酪表面病原体和腐败菌的抗菌效果。LED 照射高度抑制了李斯特菌和荧光假单胞菌在覆盖定向聚丙烯（OPP）膜（厚度 0.03mm）的琼脂培养基上的生长。当用 OPP 膜包装接种了李斯特菌或荧光假单胞菌的切片奶酪，并在 4 或 25°C 下用 LED 照射时，在 4°C 下包装切片奶酪中李斯特菌和荧光假单胞菌的减少水平高于 25°C。在 4°C 下储存 7 天后，非照射和照射的切片奶酪之间的颜色没有明显差异。在 4°C 下 LED 照射 4 天导致李斯特菌和荧光假单胞菌的细胞损伤与 RNA、蛋白质和肽聚糖代谢有关，并且从 TEM 结果观察到细胞膜破裂和细胞质成分丢失。这些结果表明，LED 照射与冷藏温度相结合，可能应用于延长包装切片奶酪的保质期，并最大程度地降低食源性疾病的风险，而不会导致颜色恶化。
