Johnsonville Sausage, Sheboygan Falls, Wisconsin 53085, USA.
J Food Prot. 2011 Dec;74(12):2018-23. doi: 10.4315/0362-028X.JFP-11-289.
The efficacy of controlling Escherichia coli O157:H7 in ground beef patties by combining irradiation with vacuum packaging or modified atmosphere packaging (MAP) was investigated. Fresh ground beef patties were inoculated with a five-strain cocktail of E. coli O157:H7 at 5 log CFU/g. Single patties, packaged with vacuum or high-CO(2) MAP (99.6% CO(2) plus 0.4% CO), were irradiated at 0 (control), 0.5, 1.0, or 1.5 kGy. The D(10)-value for this pathogen was 0.47 ± 0.02 kGy in vacuum and 0.50 ± 0.02 kGy in MAP packaging. Irradiation with 1.5 kGy reduced E. coli O157:H7 by 3.0 to 3.3 log, while 0.5 and 1.0 kGy achieved reductions of 0.7 to 1.0, and 2.0 to 2.2 log, respectively. After irradiation, the numbers of survivors of this pathogen on beef patties in refrigerated storage (4°C) did not change significantly for 6 weeks. Temperature abuse (at 25°C) resulted in growth in vacuum-packaged patties treated with 0.5 and 1.5 kGy, but no growth in MAP packages. This study demonstrated that combining irradiation with MAP was similar in effectiveness to irradiation with vacuum packaging for control of E. coli O157:H7 in ground beef patties during refrigerated storage. However, high-CO(2) MAP appeared to be more effective after temperature abuse.
研究了辐照结合真空包装或改良气氛包装（MAP）控制碎牛肉饼中大肠杆菌 O157:H7 的效果。将五株大肠杆菌 O157:H7 混合菌液以 5 对数 CFU/g 的浓度接种到新鲜的碎牛肉饼中。单块肉饼用真空或高 CO2 MAP（99.6% CO2 加 0.4% CO）包装，在 0（对照）、0.5、1.0 或 1.5 kGy 下辐照。该病原体在真空包装中的 D（10）值为 0.47 ± 0.02 kGy，在 MAP 包装中的 D（10）值为 0.50 ± 0.02 kGy。1.5 kGy 的辐照可将大肠杆菌 O157:H7 减少 3.0 至 3.3 对数，而 0.5 和 1.0 kGy 可分别减少 0.7 至 1.0 和 2.0 至 2.2 对数。辐照后，在冷藏（4°C）条件下，牛肉饼中该病原体的存活数在 6 周内没有明显变化。温度滥用（在 25°C）导致用 0.5 和 1.5 kGy 处理的真空包装肉饼中出现生长，但 MAP 包装中没有生长。本研究表明，辐照结合 MAP 对于控制冷藏碎牛肉饼中大肠杆菌 O157:H7 的效果与辐照结合真空包装相似。然而，在温度滥用后，高 CO2 MAP 似乎更有效。
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