Center for Food Safety and Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797, USA.
J Food Prot. 2012 Jun;75(6):1043-56. doi: 10.4315/0362-028X.JFP-11-505.
A study was conducted to determine survival and growth behavior of Salmonella and Listeria monocytogenes in commercially prepared mayonnaise-based potato salad, macaroni salad, and coleslaw and in hummus (initial mean pH values were 4.80 to 4.94, 4.18 to 4.31, 3.87, and 4.50 to 4.52, respectively) as affected by sodium concentration (133 to 364, 190 to 336, 146 to 272, and 264 to 728 mg/100 g, respectively) and storage at 4 or 10°C for up to 27 days. Salmonella did not grow in any of the test products. Initial populations (2.02 to 2.38 log CFU/g) decreased in coleslaw to undetectable levels (<1 CFU/25 g) within 13 days and in most formulations of macaroni salad within 20 to 27 days. Salmonella survived in highest numbers in potato salad and hummus. The presence of added sodium in macaroni salad stored at 4°C and hummus stored at 4 or 10°C appeared to protect Salmonella against inactivation. L. monocytogenes, at an initial population of 1.86 to 2.23 log CFU/g, did not grow in test products, but with the exception of coleslaw containing sodium at a concentration used in the standard (control) recipe, this pathogen was detected by direct plating (≥ 1.0 log CFU/g) in all products stored at 4 or 10°C for 27 days. L. monocytogenes populations were significantly (P < 0.05) lower in potato salad and hummus with no added sodium than in test products with added sodium after storage at 4°C. Sodium concentration did not markedly affect aerobic plate counts over the 27-day storage period. Results confirm that the acidic pH of mayonnaise-based salads and hummus is a major factor preventing growth and influencing rates of inactivation of Salmonella and L. monocytogenes. In the absence of added sodium, death of these bacteria may be more rapid. However, in general decreasing or increasing the sodium concentration in selected delicatessen salad and hummus recipes does not markedly affect the behavior of Salmonella and L. monocytogenes when products are stored at 4 or 10°C for up to 27 days.
一项研究旨在确定在商业制备的蛋黄酱土豆沙拉、通心粉沙拉和凉拌卷心菜以及鹰嘴豆泥（初始 pH 值分别为 4.80 至 4.94、4.18 至 4.31、3.87 和 4.50 至 4.52）中，沙门氏菌和单核细胞增生李斯特菌的存活和生长行为如何受到钠浓度（分别为 133 至 364、190 至 336、146 至 272 和 264 至 728mg/100g）的影响，以及在 4°C 或 10°C 下储存长达 27 天。沙门氏菌在任何测试产品中都没有生长。在 13 天内，凉拌卷心菜中的初始种群（2.02 至 2.38 log CFU/g）减少到无法检测到的水平（<1 CFU/25 g），在大多数通心粉沙拉配方中，在 20 至 27 天内减少到无法检测到的水平。沙门氏菌在土豆沙拉和鹰嘴豆泥中存活数量最多。在 4°C 下储存的通心粉沙拉和在 4°C 或 10°C 下储存的鹰嘴豆泥中添加的钠的存在似乎可以防止沙门氏菌失活。单核细胞增生李斯特菌的初始种群为 1.86 至 2.23 log CFU/g，在测试产品中没有生长，但除了含有标准（对照）配方中使用的钠的凉拌卷心菜外，在所有在 4°C 或 10°C 下储存 27 天的产品中，通过直接平板计数（≥1.0 log CFU/g）均检测到该病原体。在 4°C 储存后，与添加钠的测试产品相比，不含添加钠的土豆沙拉和鹰嘴豆中的单核细胞增生李斯特菌数量明显（P < 0.05）更低。在 27 天的储存期内，钠浓度对需氧平板计数没有显著影响。结果证实，基于蛋黄酱的沙拉和鹰嘴豆泥的酸性 pH 值是防止生长和影响沙门氏菌和单核细胞增生李斯特菌失活动率的主要因素。在没有添加钠的情况下，这些细菌的死亡可能更快。然而，一般来说，在 4°C 或 10°C 下储存长达 27 天时，降低或增加选定的熟食沙拉和鹰嘴豆泥配方中的钠浓度不会显著影响沙门氏菌和单核细胞增生李斯特菌的行为。
