Nerney Alexandra, Reitz Stuart, Kovacevic Jovana, Waite-Cusic Joy
Department of Food Science and Technology, Oregon State University, Corvallis, OR 97331, USA.
Malheur County Experiment Station, College of Agricultural Sciences, Oregon State University, Ontario, OR 97914, USA.
J Food Prot. 2025 Feb 3;88(2):100443. doi: 10.1016/j.jfp.2024.100443. Epub 2024 Dec 27.
A 2020 Salmonella outbreak was epidemiologically linked to red onions; however, insufficient cleaning and sanitation in the packinghouse expanded the recall to include all onions handled by the packing house in the preceding 3 months. Our objective was to evaluate the efficacy of dry sanitizers to reduce cross-contamination risk on food contact surfaces (FCSs) found in postharvest packing areas. Transfer of Salmonella and potential surrogates (Escherichia coli, Enterococcus faecium) to and from onions to FCS materials (high-density polypropylene, polyester-nylon conveyor belts, plywood) was quantified. Transfer rates from inoculated onions to FCS were highly variable, but did not differ by surface, averaging -1.19 log %. Transfer rates from contaminated FCS to uninoculated onions averaged 0.2 log %, with 40% (31/81) of onions having no detectable transfer. Onion variety, surface type, and species did not influence the transfer rate (p > 0.05). Commercial sanitizers and alcohol solutions were tested for efficacy of reducing targeted bacteria on FCS. Reductions were quantified after 30 s and after drying (15 min). High alcohol sanitizers (∼60%) achieved a 5-log reduction on HDPE after drying. Lower alcohol (<30%) products were ineffective (<2-log reduction). E. coli and Salmonella were comparable in sensitivity to sanitizers, but E. faecium was more sensitive (p < 0.05). Transfer and sanitizer evaluation was scaled to investigate cross-contamination in postharvest storage bins (plastic and wood). With no sanitation, inoculated plastic bin contact resulted in contamination of 49-71% of onions. Use of ∼60% alcohol solutions reduced contamination to <4% of onions (p < 0.05). Low-alcohol product significantly increased cross-contamination to 86-100% of onions (p < 0.05). These findings highlight the importance of validating sanitizer efficacy to quantify microbial reduction and cross-contamination risk on produce contact surfaces.
2020年的一次沙门氏菌暴发在流行病学上与红洋葱有关联；然而，包装厂清洁和卫生措施不足，导致召回范围扩大至包括该包装厂在前3个月处理的所有洋葱。我们的目标是评估干式消毒剂降低收获后包装区域食品接触表面（FCS）交叉污染风险的效果。对沙门氏菌及其潜在替代菌（大肠杆菌、粪肠球菌）在洋葱与FCS材料（高密度聚丙烯、聚酯尼龙输送带、胶合板）之间的转移进行了定量分析。从接种的洋葱转移到FCS的转移率变化很大，但不同表面之间没有差异，平均为-1.19对数%。从受污染的FCS转移到未接种洋葱的转移率平均为0.2对数%，40%（31/81）的洋葱未检测到转移。洋葱品种、表面类型和菌种对转移率没有影响（p>0.05）。对商业消毒剂和酒精溶液在FCS上减少目标细菌的效果进行了测试。在30秒后和干燥后（15分钟）对减少量进行了定量分析。高酒精含量的消毒剂（约60%）在干燥后对高密度聚乙烯实现了5对数的减少。低酒精含量（<30%）的产品无效（减少量<2对数）。大肠杆菌和沙门氏菌对消毒剂的敏感性相当，但粪肠球菌更敏感（p<0.05）。转移和消毒剂评估按比例扩大，以调查收获后储存箱（塑料和木质）中的交叉污染情况。在不进行消毒的情况下，接种的塑料箱接触导致49%-71%的洋葱受到污染。使用约60%的酒精溶液可将污染减少至<4%的洋葱（p<0.05）。低酒精产品显著增加交叉污染，使86%-100%的洋葱受到污染（p<0.05）。这些发现凸显了验证消毒剂效果以量化农产品接触表面微生物减少和交叉污染风险的重要性。
