Razavilar V, Genigeorgis C
Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Iran.
Int J Food Microbiol. 1998 Apr 14;40(3):149-57. doi: 10.1016/s0168-1605(98)00014-2.
The effects of concentration of NaCl (0.5 to 12.5%), methyl paraben (0.0 to 0.2%), sodium propionate (0.3%), sodium benzoate (0.1%), potassium sorbate (0.3%), pH (> 5.9) temperature (4 to 30 degrees C), storage time (up to 58 d) and inoculum (> 10(5) to > 10(-2) per ml) on the log10 probability percentage of one cell of Listeria spp. to initiate growth in a broth system were evaluated in a factorial design study. At pH 5.96 and temperature ranging from 4 to 30 degrees C the concentrations of sodium propionate, potassium sorbate, and sodium benzoate examined allowed growth of L. monocytogenes with lag phases at 4 degrees C of 18, 27 and 21 days, respectively. For 0.1 and 0.2% methyl paraben growth of all Listeria spp. was initiated at 8 degrees C and 30 degrees C, respectively. At pH 6, concentration of 12% NaCl supported the growth of L. monocytogenes at 8 to 30 degrees C, whereas 12.5% inhibited all Listeria species. Four regression equations were derived relating probability of growth initiation to temperature, concentrations of NaCl and preservatives storage time, and Listeria species specific effects. From these equations, the number of cells needed for growth initiation can be calculated. The impact of this type of quantitative study and its possible application on the development of microbial standards for foods is discussed.
在一项析因设计研究中，评估了氯化钠浓度（0.5%至12.5%）、对羟基苯甲酸甲酯（0.0%至0.2%）、丙酸钠（0.3%）、苯甲酸钠（0.1%）、山梨酸钾（0.3%）、pH值（>5.9）、温度（4至30摄氏度）、储存时间（长达58天）和接种量（每毫升>10⁵至>10⁻²）对肉汤系统中单核细胞增生李斯特菌单个细胞开始生长的log₁₀概率百分比的影响。在pH值为5.96且温度范围为4至30摄氏度时，所检测的丙酸钠、山梨酸钾和苯甲酸钠浓度允许单核细胞增生李斯特菌生长，在4摄氏度时的迟滞期分别为18天、27天和21天。对于0.1%和0.2%的对羟基苯甲酸甲酯，所有李斯特菌属分别在8摄氏度和30摄氏度开始生长。在pH值为6时，12%氯化钠浓度支持单核细胞增生李斯特菌在8至30摄氏度生长，而12.5%抑制所有李斯特菌属。推导了四个回归方程，将生长起始概率与温度、氯化钠和防腐剂浓度、储存时间以及李斯特菌属特异性效应相关联。根据这些方程，可以计算出生长起始所需的细胞数量。讨论了这类定量研究的影响及其在食品微生物标准制定中的可能应用。
