Quality attributes of chilled vacuum-packaged cold-smoked common carp (Cyprinus carpio) and cold-smoked bighead carp (Hypophthalmichthys nobilis) fillets

The aim of this research was to study the effect of vacuum packaging on selected microbiological, chemical and sensory properties of cold-smoked common carp (Cyprinus carpio) and cold-smoked bighead carp (Hypophthalmichthys nobilis) fillets stored at 3 +/- 0.5 degrees C, and to determine the shelf life of the products. Fillets were analysed on days 1, 7, 10,12, 14, 15 and 16. The total viable count was significantly higher (P < 0.01) in common carp samples than in bighead carp samples from storage day 12. At the end of experiment, the numbers of TVC in both groups of samples had not reached the value of 7 logcfu/g. No significant differences (P > 0.05) were determined between the psychrotrophic viable counts in common carp and bighead carp samples during the whole period of storage. In cold-smoked bighead carp samples, lactic acid bacteria were the dominant micro-organisms at the end of storage period. Listeria monocytogenes and Salmonella spp. were not detected in any of the examined samples. The pH values in both samples groups were quite stable and ranged from 5.97 +/- 0.08 to 6.18 +/- 0.07 in cold-smoked common carp, and from 5.80 +/- 0.08 to 5.98 +/- 0.06 in bighead carp samples. The total volatile basic nitrogen concentration increased during the storage period in both groups of samples. Based on sensory evaluation, it was concluded that vacuum-packaged cold-smoked common carp samples remained acceptable up to 15 days of storage, whereas vacuum-packaged cold-smoked bighead carp samples remained unchanged until the end of the experiment.