Microbiological quality of Finnish vacuum-packaged fishery products at retail level

Abstract

The microbiological quality of 200 vacuum-packaged cold-smoked, gravad (hot-smoked) fish products at retail level was investigated. The aerobic plate counts and lactic acid bacteria counts exceeded the level of 10 7 CFU/g in 15 % and 15 % of the sliced cold-smoked, in 14 % and 7 % of the non-sliced cold-smoked, in 16 % and 6 % of the sliced gravad and in no samples of the non-sliced gravad rainbow trout samples, respectively. The proportions of the hot-smoked rainbow trout and the hot-smoked whitefish samples with aerobic plate counts less than 10 3 CFU/g were 55 % and 70 %, respectively. The mean Enterobacteriaceae counts (log CFU/g) for the sliced and non-sliced cold-smoked and the sliced and non-sliced gravad rainbow trout samples were 1.14, 1.21, 1.77 and 1.50, respectively. The highest Enterobacteriaceae count (9.2x10 7 CFU/g) was observed in a sliced gravad rainbow trout sample. Enterobacteriaceae were not detected in the hot-smoked rainbow trout, whitefish and salmon samples. Two isolates of Yersinia spp. were found and identified as Y. intermedius and non-pathogenic Y. enterocolitica. The contamination rates for L. monocytogenes were 15 % (9 samples) for cold-smoked rainbow trout, 33 % (14 samples) for gravad rainbow trout and 2 % (one sample) for hot-smoked rainbow trout. No Staphylococcus aureus or Campylobacter jejuni/coli were found in any of the samples.