Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716, USA.
Int J Food Microbiol. 2013 Sep 2;166(2):201-6. doi: 10.1016/j.ijfoodmicro.2013.07.013. Epub 2013 Jul 19.
With increasing outbreaks of gastroenteritis associated with produce, it is important to assess interventions to reduce the risk of illness. UV, ozone and high pressure are non-thermal processing technologies that have potential to inactivate human pathogens on produce and allow the retention of fresh-like organoleptic properties. The objective of this study was to determine if UV, ozone, and high pressure are effective technologies compared to traditional chlorine spray on green onions to reduce enteric viral pathogens and to determine the effect of location of the virus (surface or internalized) on the efficacy of these processes. Mature green onion plants were inoculated with murine norovirus (MNV), hepatitis A virus (HAV) and human adenovirus type 41 (Ad41) either on the surface through spot inoculation or through inoculating contaminated hydroponic solution allowing for uptake of the virus into the internal tissues. Inoculated green onions were treated with UV (240 mJ s/cm(2)), ozone (6.25 ppm for 10 min), pressure (500 MPa, for 5 min at 20°C), or sprayed with calcium hypochlorite (150 ppm, 4°C). Viral inactivation was determined by comparing treated and untreated inoculated plants using cell culture infectivity assays. Processing treatments were observed to greatly affect viral inactivation. Viral inactivation for all three viruses was greatest after pressure treatment and the lowest inactivation was observed after chlorine and UV treatment. Both surface inoculated viruses and viruses internalized in green onions were inactivated to some extent by these post-harvest processing treatments. These results suggest that ozone and high pressure processes aimed to reduce the level of microbial contamination of produce have the ability to inactivate viruses if they become localized in the interior portions of produce.
随着与农产品相关的肠胃炎爆发越来越多，评估减少疾病风险的干预措施非常重要。紫外线、臭氧和高压是非热加工技术，有可能使农产品上的人类病原体失活，并保持类似新鲜的感官特性。本研究的目的是确定紫外线、臭氧和高压是否比传统的氯喷雾更有效，以减少大葱上的肠道病毒病原体，并确定病毒的位置（表面或内化）对这些过程效果的影响。成熟的青葱植物通过点接种或通过接种污染的水培溶液（允许病毒内化到内部组织中）在表面或内部接种鼠诺如病毒（MNV）、甲型肝炎病毒（HAV）和人腺病毒 41 型（Ad41）。接种后的青葱用紫外线（240 mJ s/cm²）、臭氧（6.25 ppm 处理 10 分钟）、压力（20°C 下 500 MPa 处理 5 分钟）或次氯酸钙（150 ppm，4°C）喷雾处理。通过细胞培养感染性测定比较处理和未处理的接种植物来确定病毒失活情况。处理方法观察到对病毒失活有很大影响。三种病毒的病毒失活率在压力处理后最高，氯和紫外线处理后最低。通过这些收获后处理，所有三种病毒的表面接种病毒和内化到青葱中的病毒都在一定程度上被灭活。这些结果表明，如果臭氧和高压等旨在减少农产品微生物污染水平的处理方法使病毒在农产品内部局部化，它们就有能力使病毒失活。
