An Evaluation of the Role of Temperature on the Safety and Quality of Raw Shellstock Oysters and Bluefish

Raw oyster shellstock was subjected to abuse conditions (7, 13, and 21°C) and sampled over a ten day storage period to gather scientific data to aid in determining whether spoilage occurred in the raw product over time before proliferation of pathogenic flora (Vibrio vulnificus) made the product unsafe. Spoilage was evaluated through pH measurements of a homogenate of the shucked meat and liquor. The olfactory acceptability of the raw oysters was evaluated in concert with the microbial and chemical evaluations. At all storage conditions, halophilic bacteria outgrew V. vulnificus by a minimum of 1 log CFU/g oyster (Colony Forming Units per gram) (p < 0.05). Olfactory acceptability was below 40% when V. vulnificus growth was at its highest (p < 0.05). Refrigerated storage should be considered a CCP for raw shellstock since even moderate temperature control kept V. vulnificus below 10⁴ approximately 1-2 Logs below the estimated infective dose for the majority of the population.