Spano G, Goffredo E, Beneduce L, Tarantino D, Dupuy A, Massa S
Institute of Alimentary Productions and Technologies, Agricultural Faculty, Foggia University, Institute Zooprofilattico of Apulia and Basilicata, Foggia, Italy.
Lett Appl Microbiol. 2003;36(2):73-6. doi: 10.1046/j.1472-765x.2003.01252.x.
The fate of Escherichia coli O157:H7 was investigated during the manufacture of Mozzarella cheese.
The Mozzarella cheese was made from unpasteurized milk which was inoculated to contain ca 10(5) cfu ml(-1)E. coli O157:H7. Two different heating temperatures (70 and 80 degrees C), commonly used during curd stretching, were investigated to determine their effects on the viability of E. coli O157:H7 in Mozzarella cheese. Stretching at 80 degrees C for 5 min resulted in the loss of culturability of E. coli O157:H7 strains, whereas stretching at 70 degrees C reduced the number of culturable E. coli O157:H7 by a factor of 10.
The results show that stretching curd at 80 degrees C for 5 min is effective in controlling E. coli O157:H7 during the production of Mozzarella cheese. Brining and storage at 4 degrees C for 12 h was less effective than the stretching.
Mozzarella cheese should be free of E. coli O157:H7 only if temperatures higher than or equal to 80 degrees C are used during milk processing.
研究大肠杆菌O157:H7在马苏里拉奶酪制作过程中的命运。
马苏里拉奶酪由未杀菌的牛奶制成，接种后每毫升含约10⁵ cfu的大肠杆菌O157:H7。研究了凝乳拉伸过程中常用的两种不同加热温度（70和80℃）对马苏里拉奶酪中大肠杆菌O157:H7活力的影响。在80℃下拉伸5分钟导致大肠杆菌O157:H7菌株失去可培养性，而在70℃下拉伸使可培养的大肠杆菌O157:H7数量减少了10倍。
结果表明，在马苏里拉奶酪生产过程中，在80℃下拉伸凝乳5分钟对控制大肠杆菌O157:H7有效。在4℃下腌制和储存12小时的效果不如拉伸。
只有在牛奶加工过程中使用高于或等于80℃的温度，马苏里拉奶酪才应不含大肠杆菌O157:H7。
