Thayer D W, Boyd G, Kim A, Fox J B, Farrell H M
United States Department of Agriculture, Agricultural Research Service, Wyndmoor, Pennsylvania 19038, USA.
J Food Prot. 1998 Aug;61(8):979-87. doi: 10.4315/0362-028x-61.8.979.
The radiation resistance and ability of Listeria monocytogenes ATCC 7644, 15313, 43256, and 49594 to multiply on irradiated, air-packed, refrigerated raw or cooked turkey breast meat nuggets (ca. 25 g) and ground turkey breast meat was investigated. Gamma-radiation D values for L. monocytogenes were significantly different on raw and cooked nuggets, 0.56 +/- 0.03 kGy and 0.69 +/- 0.03 kGy, respectively; but they were not significantly different (P < or = 0.05) on raw and cooked ground turkey meat. High populations (approximately 10(9) CFU/g) of L. monocytogenes declined during 14 days of storage at 4 degrees C in both irradiated and nonirradiated samples of raw but not of cooked ground turkey breast meat. A moderate inoculum (approximately 10(3) CFU/g) did not survive a radiation dose of 3 kGy. The population increased in cooked but not in raw samples of irradiated ground turkey meat stored at either 2 or 7 degrees C for 21 days. The D value changed significantly from 0.70 +/- 0.04 to 0.60 +/- 0.02 kGy when the product was cooked to an internal temperature of 80 degrees C before irradiation. Growth on either raw or cooked turkey meat did not alter the radiation resistance of L. monocytogenes. Analyses were performed for pH, aw, moisture, and reducing potential of raw and cooked turkey meat and for pH, amino acid profile, thiamine, and riboflavin contents of aqueous extracts of raw and cooked turkey meats without identifying the factor or factors involved in differences in the survival and multiplication of L. monocytogenes on raw and cooked meat.
研究了单核细胞增生李斯特菌ATCC 7644、15313、43256和49594在辐照、气调包装、冷藏的生或熟火鸡胸肉小块（约25克）和火鸡胸肉末上的抗辐射性及增殖能力。单核细胞增生李斯特菌在生和熟肉块上的伽马辐射D值显著不同，分别为0.56±0.03千戈瑞和0.69±0.03千戈瑞；但在生和熟火鸡胸肉末上，它们没有显著差异（P≤0.05）。在4℃储存14天期间，生的但非熟的火鸡胸肉末的辐照和未辐照样品中，高菌量（约10⁹CFU/克）的单核细胞增生李斯特菌数量均下降。中等接种量（约10³CFU/克）在3千戈瑞辐射剂量下无法存活。在2℃或7℃储存21天的辐照火鸡胸肉末熟样品中菌量增加，而生样品中未增加。当产品在辐照前煮至内部温度80℃时，D值从0.70±0.04千戈瑞显著变为0.60±0.02千戈瑞。在生或熟火鸡肉上生长均未改变单核细胞增生李斯特菌的抗辐射性。对生熟火鸡肉的pH值、水分活度、水分和还原电位以及生熟火鸡肉水提取物的pH值、氨基酸谱、硫胺素和核黄素含量进行了分析，但未确定参与单核细胞增生李斯特菌在生熟肉上存活和增殖差异的因素。
