Changes in microbial flora of Pacific oysters (Crassostrea gigas) during refrigerated storage and its shelf-life extension by chitosan
Rong Cao, Chang-hu Xue and Qi Liu
International Journal of Food Microbiology, Volume 131, Issues 2-3, 31 May 2009, Pages 272-276
2009
บทคัดย่อ
Changes in microbial flora of Pacific oysters (Crassostrea gigas) during storage at 5 ± 1 °C were analyzed and the antimicrobial activity of chitosan was studied to identify its potential in shelf-life extension. The dominant microorganisms were found to be Pseudomonas (22%) and Vibrionaceae (20%) in raw oysters. During storage, proportion of Pseudomonas increased significantly and reached 73% at the end of storage, while Vibrionaceae preserved a level of approximate 20%. Wide-spectrum antibacterial property of chitosan against the bacteria isolated from oysters was discovered, and chitosan concentration of 5.0 g/L was eventually determined for application in oyster preservation. Based on microbiological analysis, biochemical indices determination and sensory evaluation, shelf-life of oysters stored at 5 ± 1 °C was determined. Data showed that chitosan treatment extended the shelf-life of oysters from 8–9 days to 14–15 days.