Enteric pathogens such as Shiga-toxin producing Escherichia coli (STEC) and Salmonella spp. continue to be a major food safety concern for the beef industry. Currently, no single method is completely effective in controlling these pathogens during carcass processing. Previous research, however, suggested that STEC might become more susceptible to oxidative damage when exposed to carcass chilling (King et al., 2016). We aimed to test that hypothesis by evaluating the antimicrobial effects of an oxidant (chlorine dioxide, ClO2 or peroxyacetic acid, PAA) on beef meat during a simulated spray chilling process (sprayed for 4 s every 15 min for 36 cycles) and/or when applied (sprayed for 144 s) prior to spray chilling with water. In all experiments, the inactivating effects of oxidants were greatest on fat surfaces and much less effective on lean surfaces. ClO2 at 15 ppm, a non-lethal level for E. coli under optimal growth conditions, caused higher log reductions in E. coli numbers (approximately 3-log reduction) when applied during spray chilling than when applied immediately prior to 'normal' spray chilling (approximately 1-log reduction). This confirms the hypothesis that E. coli are more susceptible to oxidative stress during spray chilling. In subsequent studies, both ClO2 and PAA at lethal levels (at ≥20 and ≥ 200 ppm, respectively) applied during spray chilling resulted in pronounced inactivation of both E. coli and Salmonella enterica strains, achieving a ≥4-log reduction at the end of chilling. These results indicate that an oxidant-based application during spray chilling as an antimicrobial intervention could be effective to minimise the problems associated with enteric pathogen contamination on beef meat.

中文翻译：

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在喷雾冷却过程中使用二氧化氯和过氧乙酸作为牛肉屠体的潜在抗菌干预措施。

肠道病原体，例如产生志贺毒素的大肠杆菌（STEC）和沙门氏菌。仍然是牛肉行业关注的主要食品安全问题。当前，在single体加工过程中，没有一种单一的方法可以完全有效地控制这些病原体。然而，先前的研究表明，STEC暴露于car体冷却时可能更易受到氧化损伤的影响（King等，2016）。我们旨在通过评估模拟喷雾冷却过程（每15分钟喷雾4 s，持续36个循环）和/或何时氧化剂（二氧化氯，ClO2或过氧乙酸，PAA）对牛肉的抗菌作用来检验该假设。用水喷雾冷却之前，先喷涂（喷涂144 s）。在所有实验中 氧化剂的灭活作用在脂肪表面上最大，而在贫油表面上则无效。ClO2浓度为15 ppm（在最佳生长条件下对大肠杆菌而言是非致死水平），与在“正常”喷雾之前立即施用相比，在喷雾冷却期间施用时，导致大肠杆菌数量的对数减少（约减少3log）更高冷却（减少约1-log）。这证实了以下假设：在喷雾冷却过程中，大肠杆菌更容易受到氧化应激的影响。在随后的研究中，在喷雾冷却过程中以致死水平（分别在≥20和≥200 ppm时）施加的ClO2和PAA均导致大肠杆菌和肠炎沙门氏菌均明显失活，最终降低了≥4log令人不寒而栗。