Effect of CO2-flushed Packaging on Quality of Pink Shrimp Contaminated with Vibrio parahaemolyticus

Original Paper~~~~~~~~~~~~~~~~~~~~~~~~~~~~ CO2-flushed packaging was effective for maintaining the quality of pink shrimp contaminated with Vibrio parahaemolyticus. Contaminated shrimp were sealed in Krehalon ML VS-20 film pouches flushed with air, N2, or CO2 and stored at 20°C. CO2 concentration in the pouch was approximately 87% and was retained for at least 168 h. The numbers of V. parahaemolyticus in raw pink shrimp after 8 h (initially inoculated at 1-9 CFU·g −1 ) or 12 h (initially inoculated at 100-999 CFU·g −1 ) of storage and the maximum number of bacterial cells at steady state as a kinetic parameter of the Gompertz equation were smaller under the CO2-flushed atmosphere than under the other atmospheres. The period before reaching the enteropathogenic concentration of 10 6 CFU·g −1 was prolonged by CO2-flushed packaging. These results indicate that CO2-flushed packaging is effective for suppressing V. parahaemolyticus growth. Shrimp blackening due to the activity of polyphenol oxidase (EC 1.14.18.1) was inhibited by CO2-flushed packaging. Although CO2 reduced the pH on the surface of shrimp, sensory scores were not affected. The results obtained in the present study indicate that CO2-flushed packaging is effective for maintaining the appearance, taste, and hygiene of pink shrimp.