Elimination of <i>Vibrio parahaemolyticus</i> Contamination in Shucked Oysters (<i>Crassostrea</i> <i>plicatula</i>) to with Natural Antimicrobial Agents TeaPolyphenols

Abstract

In this study, the survival of Vibrio parahaemolyticus in suspension in the presence of tea-polyphenols for 6h was first examined. The shucked oysters containing V. parahaemolyticus then were exposed to 2048μg/mL , 1024 μg/mL and 512 μg/mL tea-polyphenols for 4h and the population ofV. parahaemolyticusin shucked oysters was determined every 1h. In addition, shucked oysters containingV. parahaemolyticusexposed into the dose of 1024 μg/mL tea-polyphenols were held at various temperature (0, 5, and 20°C) to examine survival ofV. parahaemolyticusevery 6h till 24h. Populations ofV. parahaemolyticusinoysterwere determined using 3-tube most probable number (MPN) method. The study found that the MIC of tea-polyphenols to Vibrio parahaemolyticus suspension is 1024 μg/mL; when exposed to 2048 μg/mL, 1024 μg/mLand 512μg/mL tea-polyphenols for 4h, the population ofV. parahaemolyticusinshucked oysters decreased by 3.29,2.43 and 1.84 Log10MPN/g respectively; 0, 5 and 20°C,1024μg/mL tea-polyphenols can decrease the population of V. parahaemolyticusinshucked by 4.10, 3.32 and 3.00LogMPN/g at 24thh. Sensory analysis showed that treatments of tea-polyphenols at concentrations 1024μg/mL did not cause negative effects on taste of oyster meat. These results indicated that tea-polyphenols have bactericidal effects againstV. parahaemolyticusand can be applied to shucked oysters to reduce contamination of V. parahaemolyticus.