Dept. of Animal Science, Univ. of Connecticut, Storrs, CT, U.S.A.
J Food Sci. 2013 Sep;78(9):M1399-404. doi: 10.1111/1750-3841.12174. Epub 2013 Aug 23.
This study investigated the efficacy of 3 GRAS-status, plant-derived antimicrobials (PDAs), trans-cinnamaldehyde (TC), carvacrol (CR), and β-resorcylic acid (BR) applied as an antimicrobial wash for killing Escherichia coli O157:H7 on apples. "Red delicious" apples inoculated with a 5 strain mixture of E. coli O157:H7 were subjected to washing in sterile deionized water containing 0% PDA (control), 0.15% TC, 0.35% TC, 0.15% CR, 0.30% CR, 0.5% BR, or 1% BR for 1, 3, and 5 min at 23 °C in the presence and absence of 1% soil, and surviving pathogen populations on apples were enumerated at each specified time. All PDAs were more effective in reducing E. coli O157:H7 compared to the water wash treatment (P < 0.05) and reduced the pathogen by 4- to 5-log CFU/apple in 5 min. Chlorine (1%) was the most effective treatment reducing the pathogen on apples to undetectable levels in 1 min (P < 0.05). Moreover, the antimicrobial effect of CR and BR was not affected by the presence of soil, whereas the efficacy of TC and BR was decreased in the presence of soil. Further, no bacteria were detected in the wash solution containing CR and BR; however, E. coli O157:H7 was recovered in the control wash water and treatment solutions containing TC and chlorine, in the presence of 1% soil (P < 0.05). Results suggest that the aforementioned PDAs, especially CR and BR could be used effectively to kill E. coli O157:H7 on apples when used as a wash treatment. Studies on the sensory and quality characteristics of apples treated with PDAs are needed before recommending their usage.
本研究调查了 3 种 GRAS 状态的植物源抗菌剂（PDAs）——反式肉桂醛（TC）、香芹酚（CR）和β-没食子酸（BR）作为抗菌剂在清洗苹果表面时对杀灭大肠杆菌 O157:H7 的功效。将“红元帅”苹果接种 5 种大肠杆菌 O157:H7 混合菌株，然后在无菌去离子水中用 0% PDA（对照）、0.15% TC、0.35% TC、0.15% CR、0.3% CR、0.5% BR 或 1% BR 进行清洗，在 23°C 下处理 1、3 和 5 分钟，同时存在和不存在 1%土壤，然后在每个指定时间点对苹果上存活的病原菌数量进行计数。与水清洗处理相比，所有 PDAs 都更有效地减少了大肠杆菌 O157:H7（P < 0.05），并在 5 分钟内将病原菌减少了 4-5 个对数 CFU/苹果。氯（1%）是最有效的处理方法，可在 1 分钟内将病原菌减少到无法检测的水平（P < 0.05）。此外，土壤的存在并不影响 CR 和 BR 的抗菌效果，而 TC 和 BR 的功效在土壤存在的情况下降低。此外，在含有 CR 和 BR 的清洗液中未检测到细菌，但在含有 TC 和氯的对照清洗水和处理液中，在存在 1%土壤的情况下，大肠杆菌 O157:H7 被回收（P < 0.05）。结果表明，当用作清洗处理时，上述 PDAs，尤其是 CR 和 BR，可以有效地杀灭苹果上的大肠杆菌 O157:H7。在推荐使用 PDAs 之前，需要对经过 PDAs 处理的苹果的感官和质量特性进行研究。
