Abstract:

Sensory quality, metabolic products of spoilage bacteria and change of spoilage bacteria were assayed on sterile Pseudosciaena crocea tissue blocks inoculated with spoilage bacteria, with YTVB-N/CFU and YTMA/CFU, the growth kinetic parameters of the spoilage bacteria and the yield factor of microbial metabolites, respectively, used as the index. Spoilage ability of two spoilage bacteria Shewanella putrefaciens and Pseudomonas spp., as well as the mixing of the two spoilage bacteria were analyzed on Pseudosciaena crocea stored aerobically at chilled condition. The results showed that shelf life was 168 h, 174 h, and 168h, respectively, for sterile tissue blocks inoculated with Shewanella putrefaciens, Pseudomonas spp. and their mixture, while it was relatively longer with Pseudomonas spp. The YTVB-N/CFU for Shewanella putrefaciens, Pseudomonas spp. and mixed bacteria was basically similar, meanwhile YTMA/CFU for Shewanella putrefaciens was higher than for Pseudomonas spp. and mixed bacteria. The spoilage ability of Shewanella putrefaciens was more significant than Pseudomonas spp. and mixed bacteria. Pseudomonas spp. had inhibitory effect on he growth of Shewanella putrefaciens to some extent, however it was not significant until it reached high counts. Shewanella putrefaciens was specific spoilage organism in Pseudosciaena crocea stored at chilled temperature aerobically.

Key words: Pseudosciaena crocea, dominant spoilage bacteria, spoilage ability, Shewanella putrefaciens, Pseudomonas spp.