Antibacterial and antiviral activities of thymol against salmonella and coliphage MS2 on grape tomatoes, both alone and in combination with organic acids and surfactants
Date
2011
Authors
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Publisher
University of Delaware
Abstract
Grape tomato has been classified a high-risk produce for Salmonella enterica and hepatitis A virus (HAV) contamination in recent years. The objectives of our research were therefore to develop a formula of thymol (THY) and its combination with organic acid or surfactant as effective washing solutions to reduce S. enterica and coliphage MS2 (MS2) as a surrogate for HAV on grape tomatoes. Also, the impact on the quality of grape tomatoes after washing with those antimicrobial solutions was studied. Based on our study, THY 0.2 mg/ml + sodium dodecyl sulfate (SDS) 5%+ acetic acid (AA) 2 mg/ml washing treatment not only achieved greater than 7 log reduction of S. Typhimurium on both small and large numbers of inoculated grape tomatoes, but also reduced the risk of cross-contamination by residual Salmonella in the antimicrobial solution. Furthermore, it did not significantly affect the taste, aroma, visual quality, pH and color of the grape tomato. Also, it could reduce more than 1.8 log population PFU/ml of MS2 on both of small and large scales of inoculated grape tomato. Thus, THY 0.2 mg/ml +SDS 5%+ AA 2 mg/ml could inactivate both S. Typhimurium and MS2 on grape tomatoes, and it might be applied in industry as good natural alternative to more toxic chlorine-based antimicrobial agents in the future.