Department of Food Science, The University of Tennessee, Knoxville, TN, USA.
Center for Renewable Carbon, The University of Tennessee, Knoxville, TN, USA.
Food Microbiol. 2021 May;95:103674. doi: 10.1016/j.fm.2020.103674. Epub 2020 Nov 7.
Recurring outbreaks linked to Escherichia coli O157:H7-contaminated lettuce and Salmonella enterica-contaminated sprouts highlight the need for improved food safety measures. The aim of this study was to determine the ability of a bio-based antimicrobial extract prepared from switchgrass, a dedicated energy crop, to reduce E. coli O157:H7 and S. Typhimurium populations on Formica coupons, a model food-contact surface. Overnight cultures of ~7 log CFU/mL E. coli O157:H7 and S. Typhimurium, air-dried on Formica coupons were treated with 0.625% NaClO, 70% ethanol, sterile water or different batches of switchgrass extractives (SE1, SE2, and SE3) for up to 30 min. E. coli O157:H7 was reduced by 4.43 log CFU/mL after 1 min by SE3, and to non-detectable levels after 1 min by all other treatments. Populations of S. Typhimurium LT2 (15-min drying) were reduced by 3.30 log CFU/mL with 70% ethanol, 5.38 log CFU/mL with SE1, and to non-detectable levels with 0.625% NaClO after 1 min, while S. Typhimurium ATCC 23564 (1-h drying) was non-detectable after 1 min by all treatments. Under soiled conditions, 10-min treatment with SE1 and 70% ethanol reduced both bacteria to non-detectable levels. Studies with concentrated switchgrass extractives combined with various other natural disinfectants or in hurdle approaches warrant further investigation.
反复爆发与大肠杆菌 O157:H7 污染的生菜和肠炎沙门氏菌污染的芽菜有关，这凸显了需要改进食品安全措施。本研究的目的是确定一种由柳枝稷（一种专用能源作物）制备的生物基抗菌提取物降低福米卡（一种模型食品接触表面）上大肠杆菌 O157:H7 和鼠伤寒沙门氏菌种群的能力。过夜培养物中约为 7 对数 CFU/mL 的大肠杆菌 O157:H7 和鼠伤寒沙门氏菌在福米卡上干燥后，用 0.625% NaClO、70%乙醇、无菌水或不同批次的柳枝稷提取物（SE1、SE2 和 SE3）处理，最长达 30 分钟。SE3 处理 1 分钟后，大肠杆菌 O157:H7 减少了 4.43 对数 CFU/mL，所有其他处理均减少至不可检测水平。在 15 分钟干燥条件下，70%乙醇可将鼠伤寒沙门氏菌 LT2 的菌数减少 3.30 对数 CFU/mL，SE1 可减少 5.38 对数 CFU/mL，而 0.625% NaClO 可在 1 分钟内将其减少至不可检测水平，而在 1 小时干燥条件下，所有处理均使鼠伤寒沙门氏菌 ATCC 23564 减少至不可检测水平。在污染条件下，用 SE1 和 70%乙醇处理 10 分钟可将两种细菌减少至不可检测水平。需要进一步研究浓缩柳枝稷提取物与其他各种天然消毒剂结合使用或在障碍方法中的研究。
