PDF(Pubmed)
Abstract：
The consumption of avocados and their products has been linked to outbreaks of illness caused by Salmonella enterica and Listeria monocytogenes. These pathogens have been isolated from avocados collected from farms and markets. After contact with the avocado epicarp, the cells of Salmonella and L. monocytogenes can become loosely attached (LA) by suspension in a film of water and attraction by electrostatic forces, or strongly attached (SA) by physical and irreversible attachment mechanisms. Attached cells may have greater resistance to agents used to decontaminate the fruit. The effect of applying wet steam (WS) to the epicarp of Hass avocados on the reduction LA and SA counts of Salmonella and L. monocytogenes was evaluated as a function of the exposure time. The inoculated avocados were washed and exposed to WS for 30, 45, and 60 s inside a treatment chamber. Salmonella was found to be more susceptible to WS than L. monocytogenes. The efficacy of steam in reducing LA and SA cell numbers was similar for both pathogens. Steaming avocados for 60 s reduced LA Salmonella and L. monocytogenes cells by 4.6 and 4.8 log CFU/avocado, whereas SA cells were decreased by 5.2 and 4.4 log CFU/avocado, respectively.•Steaming the avocados for 60 s produced the greatest reduction in loosely and strongly attached cells for both pathogens.•Wet steam treatment efficiently eliminated the loosely and strongly attached cells of both pathogens.•The Listeria monocytogenes attached cells showed greater resistance to steam treatment than Salmonella.
摘要：
鳄梨及其产品的消费与肠道沙门氏菌和单核细胞增生李斯特菌引起的疾病爆发有关。这些病原体是从农场和市场收集的鳄梨中分离出来的。与鳄梨果皮接触后，沙门氏菌和单核细胞增生李斯特菌的细胞可以通过悬浮在水膜中和静电力的吸引而变得松散附着（LA），或通过物理和不可逆的附着机制强烈附着（SA）。附着的细胞可能对用于净化水果的试剂具有更大的抗性。根据暴露时间的函数，评估了将湿蒸汽（WS）应用于Hass鳄梨的表皮对沙门氏菌和单核细胞增生李斯特菌的LA和SA计数减少的影响。将接种的鳄梨洗涤并在处理室内暴露于WS30、45和60s。发现沙门氏菌比单核细胞增生李斯特菌更容易感染WS。蒸汽在减少LA和SA细胞数量方面的功效对于两种病原体是相似的。蒸牛油果60秒减少了4.6和4.8logCFU/牛油果，而SA细胞减少了5.2和4.4logCFU/鳄梨，分别。•将鳄梨蒸60秒可最大程度地减少两种病原体的松散和强烈附着的细胞。•湿蒸汽处理有效地消除了两种病原体的松散和强烈附着的细胞。•单核细胞增生李斯特菌附着的细胞显示出比沙门氏菌对蒸汽处理更大的抗性。
