Inactivation of Pathogens Inoculated into Prepared Seafood Products for Manufacturing Kimbab, Steamed Rice Rolled in Dried Seaweed, by Gamma Irradiation

Abstract

Three prepared seafood products for manufacturing a laver (dried seaweed) roll, a traditional and rapidly growing ready-to-eat meal in Korea, were selected and the effects of irradiation treatment for eliminating pathogens of public health significance were investigated. The pathogens tested were Salmonella Typhimurium, Escherichia coli, Staphylococcus aureus, and Listeria ivanovii. The radiation sensitivity (D10-values or the dose required to inactivate 90% of a population) of these organisms ranged from 0.23 to 0.62 kGy in imitation crab leg, 0.31 to 0.44 kGy in surimi gel, and 0.27 to 0.44 kGy in dried seaweed. The growth of all four test organisms inoculated (10(8) CFU/g) into these foods was inhibited by irradiation during 24 h of postirradiation storage regardless of the temperature (10, 20, and 30 degrees C). L. ivanovii was not detected after a 3-kGy treatment, but the other pathogens were not detected following irradiation at 2 kGy. These studies indicated that low-dose irradiation (2 kGy or less) of prepared seafood materials can keep them microbiologically safe before manufacturing a ready-to-eat prepared meal, a laver roll.

Evaluation of the Antimicrobial Activity of Certain Irradiated and Non- Irradiated Egyptian Honey Bees' Products

“…These results were consistent with the study of (16) who found that the four bacterial isolates recovered from six different honey samples produced by three native bee species in Northern Thailand were either, gram-negative or gramvariable, short rod bacteria, which is a typical character of acetic acid bacteria.…”

“…Bee honey is usually contaminated with numerous microorganisms, among these osmophilic yeast predominates, mainly the strains of Saccharomyces, Schizosaccharomyces and Torula. In bee honey, aerobic Bacillus and anaerobic Clostridium spores as well as spores and small fragments of moulds may appear (16) .…”

Use of gamma irradiation for inactivation of pathogens inoculated into Kimbab, steamed rice rolled by dried laver

“…Coagulase positive staphylococci was isolated in 15 of 20 (75%) meatball samples, 20 of 20 (100%) cooked liver samples, and 20 of 20 (100%) Russian salad samples, at the level of 3.5, 4.9 and 5.1 log CFU/g, respectively (Ö ner, 1997). Jo et al (2005) reported that S. aureus inoculated into prepared seafood products including imitation crab leg, surimi gel and dried laver was not detected after 3 kGy of a gamma irradiation. Table 5 shows the calculated D 10 value of the irradiation treatment of the Kimbab tested.…”

“…Lee et al (2005) reported that most contamination of Kimbab was caused by food materials such as dried laver, surimi gel, seasoned and blanched spinach, and cucumber. Jo, Lee, Kang, et al (2004) and Jo et al (2005) have studied the food materials for Kimbab manufacturing and reported that low dose irradiation (less than 3 kGy) can eliminate pathogens inoculated into readyto-use foods originated from animal and seafood. The objective of the present study was to demonstrate the efficacy of irradiation treatment for eliminating the pathogens such as Salmonella Typhimurium, Escherichia coli, S. aureus and Listeria ivanovii in a manufactured Kimbab, thereby ensuring the microbiological safety of the ready-to-eat Kimbab.…”

Radiation sensitivity of selected pathogens in ice cream

“…A phenomenon similar to that observed in the present study has been reported in heat-treated foods, where damaged cells are unable to repair and tend to die in unfavorable environments (Lestiner, 1996). In addition, an extension of the lag time in the growth of the surviving cells in foods with radiation-related injuries were reported (Grant & Patterson, 1992;Jo et al, 2005aJo et al, , 2005b. After inoculation before freezing, the population of S. typhimurium was about 10 7 CFU/g ( Table 6).…”