Gamma radiation in the reduction of Salmonella spp. inoculated on minimally processed watercress (Nasturtium officinalis)
C. G. Martins, J. H. Behrens, M. T. Destro, B. D. G. M. Franco, D. M. Vizeu, B. Hutzler and M. Landgraf
Radiation Physics and Chemistry Volume 71, Issues 1-2 , September-October 2004, Pages 89-93 13th International Meeting on Radiation Processing (IMRP-2003)
2003
บทคัดย่อ
Gamma radiation in the reduction of Salmonella spp. inoculated on minimally processed watercress (Nasturtium officinalis)
Consumer attitudes towards foods have changed in the last two decades increasing requirements for freshlike products. Consequently, less extreme treatments or additives are being required. Minimally processed foods have freshlike characteristics and satisfy this new consumer demand. Besides freshness, the minimally processing also provide convenience required by the market. Salad vegetables can be source of pathogen such as Salmonella,
Escherichia coli O157:H7,
Shigella spp. The minimal processing does not reduce the levels of pathogenic microorganisms to safe levels. Therefore, this study was carried out in order to improve the microbiological safety and the shelf-life of minimally processed vegetables using gamma radiation. Minimally processed watercress inoculated with a cocktail of
Salmonella spp was exposed to 0.0, 0.2, 0.5, 0.7, 1.0, 1.2 and 1.5 kGy. Irradiated samples were diluted 1:10 in saline peptone water and plated onto tryptic soy agar that were incubated at 37°C/24 h. D10 values for
Salmonella spp. inoculated in watercress varied from 0.29 to 0.43 kGy. Therefore, a dose of 1.7 kGy will reduce Salmonella population in watercress by 4 log10. The shelf-life was increased byday when the product was exposed to 1 kGy