SURVIVAL OF LISTERIA-MONOCYTOGENES IN COTTAGE CHEESE
SURVIVAL OF LISTERIA-MONOCYTOGENES IN COTTAGE CHEESE
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DOI：
10.4315/0362-028x-58.2.128
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发表时间：
1995-02-01
影响因子：
2
通讯作者：
SHELEF, LA
中科院分区：
文献类型：
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作者：
PICCININ, DM;SHELEF, LA
大多数关于奶酪中单核细胞增生性李斯特氏菌行为的研究都集中在软的、成熟的类型上，因为人类李斯特菌病的暴发与这些食品的消费有关，而在白干酪中观察到的情况有限，而且在美国和加拿大购买的分别带有和不带有山梨醇的新鲜市场白干酪样品被单核细胞增生性李斯特菌菌株Scott A(10(3)cfu/g)污染。美国和加拿大新鲜干酪的平均总盘子数/克，log(10)分别为3.54和5.22。在5摄氏度的24天后，这两个数字分别为3.51和6.27。美国干酪新鲜时和24天后的平均pH值分别为5.05和5.03，加拿大干酪的平均pH值分别为4.89和4.77。在温度滥用(10和20摄氏度)下，所有奶酪样品的细胞数量都增加了>；3log，尽管含有山梨醇的奶酪变质速度较慢，样品即使在21天后也没有明显的表面霉菌生长。农家干酪在任何储存温度下都不支持单核细胞增多性李斯特菌的生长，在5℃下放置24天后，无山梨酸盐干酪和含山梨酸干酪的李斯特菌细胞数分别下降0.35和0.81log(10)。3%乳酸钠或乳酸钙处理不影响李斯特菌细胞数。这些发现表明，白干酪中的山梨酸酯是有效的防腐剂，但不是抗李斯特菌的药物。白干酪中李斯特菌的持续存在强调了在制造和储存过程中防止污染的必要性。
Most studies on the behavior of Listeria monocytogenes in cheeses have focused on the soft, ripened types because of human listeriosis outbreaks linked to consumption of these foods, while observations in cottage cheese are limited and conflicting Fresh market cottage cheese samples with and without sorbate, purchased in the United States and Canada, respectively, were contaminated with L. monocytogenes strain Scott A (10(3) CFU/g). Mean total plate counts/g, log(10), in the fresh U.S. and Canadian cheeses were 3.54 and 5.22, respectively. After 24 days at 5 degrees C, the respective numbers were 3.51 and 6.27. Mean pH values in the U.S. cheeses at freshness and after 24 days were 5.05 and 5.03, respectively, and values in the Canadian cheese were 4.89 and 4.77. Increases of >3 logs in cell numbers were seen at temperature abuse (10 and 20 degrees C) in all cheese samples, although sorbate-containing cheese spoiled ata slower rate and samples were free of visible surface mold growth even after 21 days. Cottage cheese did not support growth of L. monocytogenes at any of the storage temperatures, and declines (0.35 and 0.81 log(10), in sorbate-free and sorbate-containing cheese, respectively) were seen after 24 days at 5 degrees C. Treatment with 3% sodium or calcium lactate did not affect listerial cell numbers. These findings demonstrate that sorbates in cottage cheese are effective as preservatives but not as antilisterials. Persistence of listeriae in cottage cheese emphasizes the need to prevent contamination during manufacturing and storage.