Robertson C B, Andrews L S, Marshall D L, Coggins P, Schilling M W, Martin R E, Collette R
Department of Food Science, Nutrition, and Health Promotion, Mississippi State University, Box 9805, Mississippi State, Mississippi 39762, USA.
J Food Prot. 2006 Jul;69(7):1561-4. doi: 10.4315/0362-028x-69.7.1561.
Listeria monocytogenes can pose a serious threat in several areas of the nation's food supply including ready-to-eat seafood products. Use of irradiation processing can potentially reduce the risk of listeriosis caused by consumption of ready-to-eat seafood products. This study measured the effect of X-ray irradiation on reducing the population of L. monocytogenes on ready-to-eat, vacuum-packaged smoked mullet. Smoked mullet were inoculated with a five-strain mixture of L. monocytogenes (10(4) CFU/g), vacuum packaged, and irradiated (0, 0.5, 1.0, 1.5, and 2.0 kGy). The packaged fish were then stored at 3 and 10 degrees C for 90 and 17 days, respectively. Radiation doses of 0.5, 1.0, and 1.5 kGy reduced the initial population of L. monocytogenes by 1.1, 1.6, and 2.1 log CFU/g, respectively. The 2.0-kGy dose reduced L. monocytogenes to undetectable levels with no recovery growth at either temperature. Compared to the control, irradiation at 1.5 kGy demonstrated 1.0 and 1.7 log CFU/g less growth at 3 degrees C after 60 days and 10 degrees C after 17 days, respectively. Sensory flavor analysis was conducted to determine if a difference existed between irradiated samples. Panelists indicated that there were no differences among treated and untreated samples. An X-ray dose of 2 kGy effectively eliminated 10(4) CFU/g L. monocytogenes on smoked mullet without changing sensory quality.
单核细胞增生李斯特菌会在美国食品供应的几个领域构成严重威胁，包括即食海鲜产品。使用辐照加工有可能降低因食用即食海鲜产品而导致李斯特菌病的风险。本研究测量了X射线辐照对减少即食真空包装烟熏鲻鱼中单核细胞增生李斯特菌数量的影响。将烟熏鲻鱼接种单核细胞增生李斯特菌的五菌株混合物（10⁴CFU/g），进行真空包装，并辐照（0、0.5、1.0、1.5和2.0千戈瑞）。然后将包装好的鱼分别在3℃和10℃下储存90天和17天。0.5、1.0和1.5千戈瑞的辐射剂量分别使单核细胞增生李斯特菌的初始数量减少了1.1、1.6和2.1 log CFU/g。2.0千戈瑞的剂量使单核细胞增生李斯特菌降至检测不到的水平，在任何一个温度下均无恢复生长。与对照组相比，1.5千戈瑞的辐照在60天后3℃时和17天后10℃时的生长分别减少了1.0和1.7 log CFU/g。进行了感官风味分析，以确定辐照样品之间是否存在差异。小组成员表示，处理过的和未处理的样品之间没有差异。2千戈瑞的X射线剂量有效地消除了烟熏鲻鱼上10⁴CFU/g的单核细胞增生李斯特菌，而没有改变感官质量。
