Chen Ning, Shelef Leora A
Department of Nutrition and Food Science, Wayne State University, Detroit, Michigan 48202.
J Food Prot. 1992 Aug;55(8):574-578. doi: 10.4315/0362-028X-55.8.574.
The relationship between water activity (a), lactate, and growth of Listeria monocytogenes strain Scott A was studied in a meat model system consisting of cooked strained beef ranging in moisture content from 25 to 85% (wt/wt). Lactate (4%) depressed meat a, and differences between a values in control and lactate-treated samples at each moisture level increased progressively with decrease in moisture, from 0.003 (85% moisture) to 0.046 (25% moisture). Maximum cell numbers per g in control samples stored at 20°C for 7 d were about 10 (45-85% moisture, a= 0.981-0.994) and 10 (35% moisture, a = 0.965); there was no growth in meat with 25% moisture (a = 0.932). Sodium lactate (4%) suppressed listerial growth at >55% and inhibited growth in samples with 25-55% moisture (a < 0.964). Lactate concentrations less than 4% were not listeristatic, but combinations of 2 or 3% lactate with 2% NaCl in samples with 55% moisture inhibited growth. Potassium and calcium lactate were as effective as the sodium salt in suppressing growth and a.
在一个由含水量为25%至85%（重量/重量）的熟绞碎牛肉组成的肉类模型系统中，研究了水分活度（a）、乳酸与单核细胞增生李斯特菌斯科特A菌株生长之间的关系。乳酸（4%）降低了肉的水分活度，在每个水分水平下，对照样品和乳酸处理样品的水分活度值之差随着水分含量的降低而逐渐增加，从0.003（85%水分）增加到0.046（25%水分）。在20°C下储存7天的对照样品中，每克的最大细胞数约为10（45 - 85%水分，a = 0.981 - 0.994）和10（35%水分，a = 0.965）；水分含量为25%（a = 0.932）的肉中没有生长。乳酸钠（4%）在水分含量>55%时抑制李斯特菌生长，在水分含量为25 - 55%（a < 0.964）的样品中抑制生长。乳酸浓度低于4%时没有抑菌作用，但在水分含量为55%的样品中，2%或3%的乳酸与2%的氯化钠组合可抑制生长。乳酸钾和乳酸钙在抑制生长和水分活度方面与钠盐一样有效。
