Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, South Korea.
Department of Food and Biotechnology, College of Science and Technology, Korea University, Sejong 30019, South Korea.
Food Res Int. 2023 Apr;166:112601. doi: 10.1016/j.foodres.2023.112601. Epub 2023 Feb 17.
Raw enoki mushroom is a high-risk vector for listeriosis, which led to foodborne outbreaks resulting in four deaths in the United States in 2020. This study aimed to investigate the washing method for the inactivation of L. monocytogenes in enoki mushrooms for household and food service establishments. Five methods of washing fresh agricultural products without using disinfectants were selected: (1) rinsing under running water (2 L/min, 10 min), (2-3) dipping in water (200 ml/20 g) at 22 or 40 °C for 10 min, and using (4) 10% NaCl or (5) 5% vinegar at 22 °C for 10 min. The antibacterial efficacy of each washing method along with the final rinse was tested with enoki mushrooms inoculated with a 3-strain cocktail of L. monocytogenes (ATCC 19111, 19115, 19117; ca. 6 log CFU/g). The 5% vinegar showed a significant difference in antibacterial effect compared to the other treatments except 10% NaCl (P < 0.05), with the maximum elimination of L. monocytogenes by 1.23 log CFU/g. Therefore, a disinfectant for enoki mushrooms that can complement the commonly used washing method was developed using antimicrobials (caprylic acid, CA: 0, 0.20, 0.40%; thymol, TM: 0, 0.075, 0.15%). By combined treatment of 0.40% CA and 0.15% TM at 22 °C for 10 min, L. monocytogenes was completely inactivated (>5.55 log reduction CFU/g) and did not recover after enrichment, although individual treatments of antimicrobials showed low bactericidal effects of <1.50 log reduction CFU/g. The bacterial membrane disintegration induced by the disinfectant was analyzed through flow cytometry. Additionally, the sensory scores (odor and appearance) and color parameters (L*, a*, and b*) of enoki mushrooms treated with the disinfectant were not significantly different from those of enoki mushrooms washed with water (P > 0.05). Our findings suggest a washing disinfectant consisting of low concentrations of CA and TM with synergistic antibacterial effects without quality deterioration that can ensure the safe consumption of raw enoki mushrooms in homes and food service establishments.
生金针菇是李斯特菌病的高风险载体，这导致 2020 年美国发生了四起食源性疫情，导致四人死亡。本研究旨在调查家庭和餐饮场所中用于灭活金针菇中李斯特菌的洗涤方法。选择了五种不使用消毒剂的新鲜农产品洗涤方法：（1）用 2L/min 的自来水冲洗（10 分钟），（2-3）在 22 或 40°C 的水中浸泡 10 分钟（200ml/20g），并使用（4）在 22°C 下用 10%NaCl 或（5）5%醋浸泡 10 分钟。用李斯特菌三菌株鸡尾酒（ATCC 19111、19115、19117；约 6 log CFU/g）接种金针菇，测试了每种洗涤方法的抗菌效果以及最后的冲洗效果。与其他处理方法相比，5%的醋在抗菌效果上有显著差异，除了 10%的 NaCl（P<0.05）外，李斯特菌的最大消除率为 1.23 log CFU/g。因此，开发了一种使用抗菌剂（辛酸，CA：0、0.20、0.40%；麝香草酚，TM：0、0.075、0.15%）补充常用洗涤方法的金针菇消毒剂。在 22°C 下用 0.40%CA 和 0.15%TM 联合处理 10 分钟，可完全灭活李斯特菌（>5.55 log 减少 CFU/g），即使单独使用抗菌剂的处理效果也低于 1.50 log 减少 CFU/g。通过流式细胞术分析了消毒剂引起的细菌膜破裂。此外，用消毒剂处理的金针菇的感官评分（气味和外观）和颜色参数（L*、a和 b）与用水洗涤的金针菇没有显著差异（P>0.05）。我们的研究结果表明，一种由低浓度 CA 和 TM 组成的洗涤消毒剂具有协同的抗菌作用，且不会降低质量，可以确保家庭和餐饮场所中食用生金针菇的安全。
