Radiation inactivation of some food-borne pathogens in fish as influenced by fat levels

Abstract

A . K AM A T A ND P . T HO M AS . 1988. 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°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 D 10 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 (D 10 ) 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.

Effect of gamma irradiation and frozen storage on the quality of fresh water prawn (Macrobrachium rosenbergii) and tiger prawn (Penaeus monodon)

“…Unirradiated and irradiated tiger prawn (Macrobrachium rosenbergii) stored for 56 days at À20 C. (Kilgen, 2001). The D 10 value of Salmonella typhimurium ranged between 0.10 and 0.15 kGy in shrimps homogenate irradiated at refrigeration temperature (Kamat & Thomas, 1998). Earlier, Licciardello, Nickerson, and Goldblith (1970) reported that the D 10 value of Salmonella sp.…”

Radiation Processing to Improve the Quality of Fishery Products

“…The radiation sensitivity of several pathogens, including L. monocytogenes, Y. enterocolitica, and S. typhimurium, was not affected by the fat content of fish, which ranged from 0.39 to 32.5%. 142 The microbial flora of fresh fillets of Atlantic cod caught in the summer months composed of mesophilic Gram- Irradiation of the fillets at 1 to 3 kGy completely inhibited microbial growth until the 7th day when Micrococcus sp. predominated.…”

Mapping trends in novel and emerging food processing technologies around the world

“…The best known applications which were approved for use are for raw meat, fruit and vegetables, and eggs and spices. However some research had shown its efficacy on fish and oysters (Kamat et al, 1998;Praveen et al, 2013). Milk released off-flavours when subjected to irradiation (Wertheim et al 1957).…”