Agricultural and Environmental Research Station, West Virginia State University, Institute, WV, USA.
Department of Food Science, Rutgers University, New Brunswick, NJ, USA.
Food Sci Technol Int. 2023 Sep;29(6):564-572. doi: 10.1177/10820132221101265. Epub 2022 May 11.
has been linked to fresh produce and detected in the retail environment. This study simulated the retail practices (crisping, misting, and storage) of unbagged whole heads of romaine lettuce to determine the growth of and natural psychrotrophic microflora. Three nalidixic acid-resistant strains of strains were inoculated to each head of lettuce (≈5 log CFU/g). For crisping, 24 heads of romaine lettuce were immersed in tap water or electrolyzed water (EW; free chlorine: 55 ppm) for 5 min, followed by holding at 5 °C for 2 h. The water-crisped (WC), EW crisped (EWC), or non-crisped (NC) lettuces were placed in a commercial refrigerated cabinet for misting at 5 °C. After 24-h misting, heads of lettuce were placed in perforated drain boxes with cover at 5 °C or 15 °C. The tap water and EW crisping achieved 1.3 and 2.9 log CFU/g reduction of , respectively. Approximately 1 log additional reduction of in the non-crisped lettuce was shown after misting ( < 0.05), but no significant effect of misting on the population of was observed on WC or EWC lettuces ( > 0.05). Regardless of the storage temperature or misting, populations remained significantly ( < 0.05) lower on EWC lettuce than NC and WC lettuce. On days 4 and 7 of storage, the natural psychrotrophic bacteria on lettuce stored at 5 °C was significantly lower than stored at 15 °C, and its population was not affected by crisping and misting. These provide insight into the influence of retail lettuce handling practices on the risk of .
已与新鲜农产品有关联,并在零售环境中检测到。本研究模拟了未包装的整头罗马生菜的零售操作(脆化、喷雾和储存),以确定 和自然嗜冷微生物的生长情况。将三种耐萘啶酸的 菌株接种到每头生菜(≈5 对数 CFU/g)。对于脆化,将 24 头罗马生菜浸入自来水或电解水(EW;游离氯:55ppm)中 5 分钟,然后在 5°C 下保持 2 小时。将水脆化(WC)、EW 脆化(EWC)或不脆化(NC)的生菜放在商业冷藏柜中,在 5°C 下喷雾。喷雾 24 小时后,将生菜头放在带盖的穿孔排水盒中,在 5°C 或 15°C 下储存。自来水和 EW 脆化分别使 减少了 1.3 和 2.9 对数 CFU/g。喷雾后,不脆化生菜中的 进一步减少了约 1 对数( < 0.05),但 WC 或 EWC 生菜的喷雾对 种群没有明显影响( > 0.05)。无论储存温度或喷雾如何,EWC 生菜上的 种群始终明显低于 NC 和 WC 生菜( < 0.05)。在储存第 4 天和第 7 天,在 5°C 下储存的生菜上的天然嗜冷细菌明显低于在 15°C 下储存的生菜,且其种群不受脆化和喷雾的影响。这些结果为零售生菜处理方式对 的风险的影响提供了深入了解。