P1-150 Modeling of the Cross-contamination of Vibrio parahaemolyticus in Shrimp Peeling Process

Monday, August 1, 2016
America's Center - St. Louis
Xingning Xiao, Zhejiang University, Hangzhou, China
Wen Wang, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
Yingchun Fu, Zhejiang University, Hangzhou, China
Weihuan Fang, Zhejiang University, Hangzhou, China
Yanbin Li, University of Arkansas, Fayetteville, AR
Introduction: Vibrio parahaemolyticus has been recognized as the leading cause of seafood-borne illness all over the world. The cross-contamination of Vibrio parahaemolyticus could be caused by gloves in the shrimp peeling process, which is a critical control point for ensuring the safety of peeled shrimps. However, the bacterial transfer due to the gloves in shrimp peeling process has not been studied well.

Purpose: The purpose of this study was to investigate the cross-contamination of Vibrio parahaemolyticus due to gloves and develop a mathematic model for describing the bacterial transfer in shrimp peeling process.

Methods:  A pair of clean gloves was used to peel fifteen shrimps consecutively. The first shrimp was inoculated with three-strain cocktail Vibrio parahaemolyticus and the other fourteen shrimps were sterilized. Three inoculation levels of 6, 7 and 8 log CFU/ml were considered in this study. Bacterial concentration of each shrimp was investigated after peeling. A Weibull model was developed for describing the bacterial transfer in the peeling process, and ANOVA was used to test the significance and variance of the model.

Results: The subsequent bacterial transfers on non-inoculated shrimps from the contaminated gloves were found in all shrimps. A maximum of 5 log CFU/g of Vibrio parahaemolyticus could be transferred via gloves. The transfer took place at two distinguishable rates. The initial steeper slope at first seven shrimps, which demonstrated a fast bacterial transfer, is followed by a persistent low bacterial populations recovered from the last eight shrimps, forming a smooth tail of data points. Statistical indices (R2=0.99; P<0.0001; RMSE=0.00034 and SEP=14%) indicated the satisfactory performance of the Weibull model.

Significance: The results of the study provide the information on cross contamination in shrimp processing plant and the constructed model could be a useful tool for the risk assessment during shrimp peeling process.