School of Agriculture and Environmental Sciences, Central University of Technology, Bloemfontein, Free State Province, South Africa.
Foodborne Pathog Dis. 2012 Dec;9(12):1126-9. doi: 10.1089/fpd.2012.1220. Epub 2012 Nov 28.
This article reports on the antilisterial properties of selected organic acids and salt derivatives in order to suggest possible alternatives in food preservation and pathogen control in the poultry meat processing industry. The susceptibility of two Listeria monocytogenes isolates was assessed against five organic acids (lactic, acetic, malic, citric, and propionic) and two acid-salt derivatives (sorbic acid [potassium salt] and benzoic acid [sodium salt]) across a series of pH environments. Minimum inhibitory concentrations (MICs) of the acids were tested against the two strains by means of an agar-dilution method. In general, strain CC60 was found to be more resistant than strain CC77 to both organic acids and salts. At pH values of 7 and above, high MIC levels (low susceptibility) were noted for potassium sorbate, sodium benzoate, and lactic acids, whereas susceptibility at lower pH increased reaching pH5 where the isolates were susceptible to all the organic acids tested. A small increase in pH notably reduced antimicrobial activity against the organisms. At pH 7, the isolates just about lost susceptibility to benzoic, lactic, malic, and sorbic acids. Although the activity of the majority of acids was linked to pH, some acids were not as closely related (e.g., potassium sorbate, sodium benzoate, and citric acid), and this suggests that the type of organic acids plays a role in inhibition. The relatively high MICs reported for compounds that are conventionally used as preservatives against Listeria spp. raise concern. The results furthermore suggest that the type of organic acid used to set pH, and not only pH alone, plays a role in determining inhibition. It was confirmed that a "one size fits all" approach to preservation is not always effective. Furthermore, the need for microbiological data to the subspecies level to inform the selection of preservatives was highlighted.
本文报道了几种有机酸和盐衍生物的抗李斯特菌特性，以期为食品保鲜和控制禽肉加工业中病原体提供可能的替代品。评估了两种李斯特菌分离株对五种有机酸（乳酸、乙酸、苹果酸、柠檬酸和丙酸）和两种酸盐衍生物（山梨酸钾和苯甲酸钠）在一系列 pH 环境下的敏感性。通过琼脂稀释法测试了酸对两种菌株的最低抑菌浓度（MIC）。一般来说，与两种有机酸和盐相比，CC60 菌株比 CC77 菌株更具抗性。在 pH 值为 7 及以上时，山梨酸钾、苯甲酸钠和乳酸的 MIC 值较高（低敏感性），而在较低 pH 值时敏感性增加，在 pH5 时两种分离株对所有测试的有机酸均敏感。pH 值略有升高显著降低了对这些生物的抗菌活性。在 pH7 时，分离株几乎失去了对苯甲酸、乳酸、苹果酸和山梨酸的敏感性。虽然大多数酸的活性与 pH 有关，但有些酸的关系并不密切（例如山梨酸钾、苯甲酸钠和柠檬酸），这表明有机酸的类型在抑制中起作用。报告的用于抑制李斯特菌的常规防腐剂的相对较高的 MIC 值令人担忧。结果还表明，用于设定 pH 值的有机酸类型，而不仅仅是 pH 值本身，在决定抑制方面起着作用。事实证明，“一刀切”的保鲜方法并不总是有效。此外，还强调了需要针对亚种水平的微生物数据来选择防腐剂。
