Preliminary analysis on the ability to spoilage of Pseudosciaena crocea' spoilage bacteria

TVBN,TMA and sensory quality changes and the growth of Shewanella putrefaciens for sterile Pseudosciaena crocea tissue blocks inoculated Shewanella putrefaciens stored aerobically at 5℃ were mainly assayed.The yield factor for production of trimethylamine(YTMA/cfu) and the cell concentration determined at the time of off-odour detection were used as quantitative measurements of microbial spoilage ability.The results showed that the limit for sensory acceptability was 157h.At rejection point,TVBN,TMA and counts of Shewanella putrefaciens were 27.82mg/100g,18.01mg/100g and 3.09×109cfu/g,respectively.The maximum counts of Shewanella putrefaciens were more than these at spoilage point suggesting this organism could be responsible for spoilage.And YTMA/CFU of Shewanella putrefaciens was 3.59×10-9mg-N TMA/cfu.These quantitative results indicated that Shewanella putrefaciens had a high spoilage potential,but this organism had a low spoilage activity and high cell concentrations were required to cause spoilage.