Abdallah Angelica, Silva Juan L, Schilling Wes, Stafne Eric T, White Shecoya B
Department of Biochemistry, Nutrition, and Health Promotion, Mississippi State University, Mississippi State, Mississippi 39762, USA.
South Branch Experiment Station, Coastal Research and Extension Center, Mississippi State University, Poplarville, MS 39470, USA.
J Food Prot. 2025 Jul 21;88(8):100559. doi: 10.1016/j.jfp.2025.100559. Epub 2025 Jun 13.
The antimicrobial effect of various concentrations of chlorine dioxide (ClO) and muscadine extract (ME) was investigated on Escherichia coli O157:H7 and Listeria monocytogenes under in vitro conditions and on treated spinach and blueberries. Tryptic soy broth (TSB) and produce were inoculated with a 3-strain cocktail of each pathogen. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using either 96-well plates incubated in a microplate reader for ClO or test tubes incubated in a conventional incubator at 37 °C for 24 h for the ME. Pathogen reduction on inoculated produce (inoculation levels were 5.6-7.0 log CFU/g for spinach and 4.5-5.1 log CFU/g for blueberries) was evaluated after exposure to various antimicrobial treatments for 10 min + 30-45 min dry time + storage at 8 °C for up to six days. Under in vitro, L. monocytogenes was more susceptible than E. coli O157:H7 to ClO and ME. On spinach, 300 mg/ml ME and 3 ppm ClO + 300 mg/ml ME treatments resulted in the maximum reduction of E. coli O157:H7 (4.6 log CFU/g reduction at day 1) and L. monocytogenes (5.6 log CFU/g reduction at day 2), respectively. On blueberries, all the treatments significantly decreased E. coli O157:H7 counts (≤1.7 log CFU/g), and no differences (P > 0.05) were detected from day 1 to day 6. The treatment 3 ppm ClO + 300 mg/ml ME led to nondetectable (P ≤ 0.05) L. monocytogenes levels on blueberries at days 1, 2, 4, and 6, leading to surface reductions >4.1 log CFU/g. Based on the study, ME combined with ClO could be a potential candidate as postharvest treatment to reduce the presence of E. coli O157:H7 and L. monocytogenes on blueberries. Both pathogens were less susceptible to these combined treatments on spinach.
研究了不同浓度的二氧化氯（ClO）和葡萄提取物（ME）在体外条件下以及对处理后的菠菜和蓝莓上的大肠杆菌O157:H7和单核细胞增生李斯特菌的抗菌效果。用每种病原体的三菌株混合菌液接种胰蛋白胨大豆肉汤（TSB）和农产品。使用96孔板在酶标仪中孵育测定ClO的最小抑菌浓度（MIC）和最小杀菌浓度（MBC），对于ME则使用试管在37℃的传统培养箱中孵育24小时进行测定。对接种后的农产品（菠菜的接种水平为5.6 - 7.0 log CFU/g，蓝莓的接种水平为4.5 - 5.1 log CFU/g）进行各种抗菌处理10分钟 + 30 - 45分钟干燥时间 + 在8℃下储存长达6天后，评估病原体减少情况。在体外，单核细胞增生李斯特菌比大肠杆菌O157:H7对ClO和ME更敏感。在菠菜上，300 mg/ml ME和3 ppm ClO + 300 mg/ml ME处理分别导致大肠杆菌O157:H7（第1天减少4.6 log CFU/g）和单核细胞增生李斯特菌（第2天减少5.6 log CFU/g）的最大减少。在蓝莓上，所有处理均显著降低了大肠杆菌O157:H7的数量（≤1.7 log CFU/g），从第1天到第6天未检测到差异（P > 0.05）。3 ppm ClO + 300 mg/ml ME处理在第1、2、4和6天导致蓝莓上的单核细胞增生李斯特菌水平未检出（P≤0.05），表面减少>4.1 log CFU/g。基于该研究，ME与ClO联合使用可能是一种潜在的采后处理方法，以减少蓝莓上大肠杆菌O157:H7和单核细胞增生李斯特菌的存在。这两种病原体在菠菜上对这些联合处理的敏感性较低。
