Control of natural microbial flora and Listeria monocytogenes in vacuum-packaged trout at 4 and 10 degrees C using irradiation
(EN)
Savvaidis, I. N.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Savvaidis, I. N.
(EN)
The effect of gamma irradiation on the natural microflora of whole salted vacuum-packaged trout at 4 and 10degreesC was studied. In addition. the effectiveness of gamma irradiation in controlling Listeria monocytogenes inoculated into trout was investigated. Irradiation at doses of 0.5 and 2 kGy affected populations of bacteria. namely, Pseudomonas spp., Brochothrix thermosfacta, lactic acid bacteria, H(2)S-producing bacteria typical of Shewanella putrefaciens, and Enterobacteriaceae, at both 4 and 10degreesC. This effect was more pronounced at the higher dose 2 kGy) and the lower temperature (4degreesC). Pseudomonads, H(2)S-producing bacteria typical of S. putrefaciens, and Enterobacteriaceae showed higher sensitivity to gamma irradiation than did the rest of the microbial species. Sensory evaluation did not show a good correlation with bacterial populations. On the basis of sensory odor scores. a shelf life of 28 days (2 kGy, 4degreesC) was obtained for salted vacuum-packaged freshwater trout, compared with a shelf life of 7 days for the unirradiated sample. Under the same conditions, the growth of L. monocytogenes inoculated into the samples was suppressed by 2 log cycles after irradiation (2 kGy) and storage for up to 18 days at 4degreesC.
(EN)
