Inhibitory Effect And Damage Mechanism Of Natural Edible Components On Vibrio Parahaemolyticus

Vibrio parahaemolyticus is the most prevalent foodborne pathogen in China,especially in the coastal cities. This paper investigated the effects of three edible naturalcomponents (acetic acid、 alcohol and tea-polyphenol) on survival of Vibrioparahaemolyticus in cultural broth using single factor experiment and orthogonalexperiment. According to single factor experiment, Vibrio parahaemolyticus could notdetected after being treated in50%alcohol or0.125mg/mL tea-polyphenol solution for5min. In addition, the bacteria populations could be reduced by4.79Log10CFU/mLwhen Vibrio parahaemolyticus cells were treated in an acetic acid solution (pH2) for5minutes. According to an orthogonal experiment, the combination of alcohol, organicacid and tea-polyphenol could achieve synergistic inhibitory effects on Vibrioparahaemolyticus. It was found that Vibrio parahaemolyticus could hardly survive afterbeing treated in an acetic acid solution (pH2.8) containing25%alcohol and0.125mg/mL tea-polyphenol, or in an acetic acid solution (pH2.4) containing12%alcohol and0.125mg/mL tea-polyphenol.Effects of three complex antimicrobial on reducing pathogens contamination onseafoods were studied in this paper. Fish, shrimp and shellfish were inoculated withVibrio parahaemolyticus and treated by complex antimicrobial for a list of time. Thepopulations of bacteria in raw fish, shrimp and shellfish were reduced more than99%by treating for60minutes. The populations of Vibrio parahaemolyticus in raw fish,shrimp and shellfish were reduced more than4-5order of magnitudes. The resultsshowed that antimicrobial effects of complex antimicrobial on Vibrio parahemolyticusand total bacteria in different kind of seafood are good. So application of complexantimicrobial following thorough seafood processing could greatly reduce pathogenscontamination and improve safety for consumption. The organoleptic properties of rawfish, shrimp and shellfish were barely affected by treating on three types of complexantimicrobial. The color, odor, muscle tissue, taste and overall acceptability of rawseafood were slightly affected by the complex antimicrobial.Action mechanisms and damaged effects of alcohol, organic acid andtea-polyphenol against Vibrio parahemolyticus were studied. The change of growth curves, cell ultrastructure, cell membrane permeability, extracellular proteins, outermembrane protein and superoxide dismutase between normal vibrio parahemolyticusand the vibrio parahemolyticus affected by antimicrobial. The results indicated thatalcohol could damage the structures of cell wall and cell membrane, causing an increasein cell membrane permeability, the release of intracellular contents, and consequentlyresulting in growth inhibition and even death of the cell. The cell wall was fractured andbreached, the cytoplasm leaked out by treating on organic acid. Tea-polyphenol coulddamage the structure of cell membrane and outer membrane protein, which resulted inthe increase of permeability of cell membrane and release of cell components, whichinfluenced the cell composition, and finally leading to the lost of normal physiologicalfunction of bacterium. Three nature edible components could significant reduce theactivity of superoxide dismutase.After all, the results of this study suggested that combination of alcohol, organicacid and tea-polyphenol may be applied as composite antibacterial agents for reducingrisks of Vibrio parahaemolyticus infection associated with seafood consumption.