Kamat A, Thomas P
Food Technology Division, Bhabha Atomic Research Centre, Mumbai, India.
J Appl Microbiol. 1998 Apr;84(4):478-84. doi: 10.1046/j.1365-2672.1998.00369.x.
The influence of low (0.39-1.1%), medium (4.25%) and high (7.1-32.5%) fat levels in fish on radiation inactivation of four food-borne pathogens was investigated. Cells of Listeria monocytogenes 036, Yersinia enterocolitica F5692, Bacillus cereus and Salmonella typhimurium at logarithmic phase were inoculated in 10% fish homogenates and subjected to gamma irradiation at ice temperature (0-1 degree C) with doses ranging from 0.05 to 0.8 kGy. The radiation survival curves of L. monocytogenes and B. cereus were characterized by shoulders, while a tailing effect was depicted by cells of Y. enterocolitica and B. cereus. The D10 values in kGy calculated on the exponential part of the curve ranged from 0.2 to 0.3, 0.15 to 0.25, 0.1 to 0.15 and 0.09 to 0.1 for L. monocytogenes 036, B. cereus, Salm. typhimurium and Y. enterocolitica F5692, respectively. This order (D10) of radiation resistance of each organism was not affected by the fat content of the fish. Inoculated pack studies carried out separately with each pathogen in fatty (Indian sardine, 7.1%) and lean (Golden anchovy, 0.39%) fish showed no difference in their survival after exposure to 1 kGy and 3 kGy doses, which corroborated the above observation. The practical significance of these results in the application of the technology is discussed.
研究了鱼肉中低（0.39 - 1.1%）、中（4.25%）和高（7.1 - 32.5%）脂肪水平对四种食源性病原体辐射灭活的影响。将处于对数期的单核细胞增生李斯特菌036、小肠结肠炎耶尔森菌F5692、蜡样芽孢杆菌和鼠伤寒沙门氏菌的细胞接种到10%的鱼肉匀浆中，并在冰温（0 - 1℃）下用0.05至0.8千戈瑞的剂量进行伽马辐照。单核细胞增生李斯特菌和蜡样芽孢杆菌的辐射存活曲线具有肩部特征，而小肠结肠炎耶尔森菌和鼠伤寒沙门氏菌的细胞呈现拖尾效应。根据曲线指数部分计算得出的D10值（单位为千戈瑞），单核细胞增生李斯特菌036、蜡样芽孢杆菌、鼠伤寒沙门氏菌和小肠结肠炎耶尔森菌F5692分别为0.2至0.3、0.15至0.25、0.1至0.15和0.09至0.1。每种微生物的这种辐射抗性顺序（D10）不受鱼肉脂肪含量的影响。分别用富含脂肪的鱼（印度沙丁鱼，7.1%）和瘦鱼（金色小沙丁鱼，0.39%）对每种病原体进行接种包装研究，结果表明在暴露于1千戈瑞和3千戈瑞剂量后，它们的存活率没有差异，这证实了上述观察结果。文中还讨论了这些结果在该技术应用中的实际意义。
