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.