Wang Jiayi, Sun Yeting, Tao Dongbing, Wang Shan, Li Chen, Zheng Fenge, Wu Zhaoxia
College of Food Science, Shenyang Agricultural University, 120 Dongling Rd., Shenyang 110866, China.
Vegetable Research Center, Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
Microorganisms. 2019 Sep 20;7(10):373. doi: 10.3390/microorganisms7100373.
Lactic acid (LA) and acetic acid (AA) are independently used to disinfect fresh leaf vegetables. LA has a higher efficacy but costs more than AA. Herein, we compared the disinfection efficacy of LA, AA, and their mixture on lettuce to determine whether the cheaper acid mixture shows similar or more efficacy than LA. Quality analysis indicated that the acid mixture and individual acids did not cause additional loss of instrument color and polyphenolic content compared with that of the control; however, visible defects were observed at AA concentrations exceeding 0.8%. Analysis of O157:H7, Listeria , and naturally present microbes (aerobic mesophilic and psychrotrophic bacteria, coliforms, molds, and yeasts) showed that the acid mixture led to the highest reduction in microbial count during storage. 16S rRNA sequencing was further employed to understand the effects of the acid mixture and individual acids on lettuce microbial ecology. During storage, the acid mixture and individual acids significantly decreased the abundance of spp. and spp. but there was a marked increase in abundance (LA: 0.003-58.82%; AA: 0.01-55.34%; acid mixture: undetected to 50.71%; control: 0.007-33.09%), indicating that acid disinfection altered the microbial ecology to stimulate growth. These results enhance our understanding of the relationship between lettuce disinfection and ecological changes.
乳酸（LA）和乙酸（AA）被分别用于新鲜叶菜类蔬菜的消毒。乳酸的消毒效果更好，但成本高于乙酸。在此，我们比较了乳酸、乙酸及其混合物对生菜的消毒效果，以确定成本较低的酸混合物是否具有与乳酸相似或更高的消毒效果。品质分析表明，与对照组相比，酸混合物和单一酸不会导致仪器颜色和多酚含量的额外损失；然而，当乙酸浓度超过0.8%时，会出现可见缺陷。对O157:H7、李斯特菌以及自然存在的微生物（需氧嗜温菌和嗜冷菌、大肠菌群、霉菌和酵母菌）的分析表明，酸混合物在储存期间导致微生物数量的减少最多。进一步采用16S rRNA测序来了解酸混合物和单一酸对生菜微生物生态的影响。在储存期间，酸混合物和单一酸显著降低了 spp. 和 spp. 的丰度，但 丰度显著增加（乳酸：0.003 - 58.82%；乙酸：0.01 - 55.34%；酸混合物：未检测到至50.71%；对照组：0.007 - 33.09%），这表明酸消毒改变了微生物生态以刺激 生长。这些结果增进了我们对生菜消毒与生态变化之间关系的理解。
