Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 19, 2008
Publication Date: September 19, 2008
Citation: Kingsley,D. 2008.High Pressure Inactivation of Foodborne viruses [abstract].Conference on High Pressure Bioscience and Biotechnology.LaJolla,CA.p.1.
Over the past half dozen years or so, the USDA Seafood Safety laboratory has endeavored to evaluate the potential of high pressure processing (HPP) for inactivation of food-borne viruses. As a commercial food technology, high pressure processing is highly advantageous because it can inactivate pathogens while retaining much of the uncooked taste and character of foods. We have investigated and characterized the effects of HPP on numerous potential food-borne viruses such as hepatitis A virus (HAV), Aichi virus, coxsackieviruses, and poliovirus. Since there are no laboratory assays for infectious human norovirus, research surrogates such as feline calicivirus (FCV) and murine norovirus have been studied. Results indicate some potential food-borne viruses are resistant to pressure. However for HAV and norovirus, the two viruses of principle food-borne concern, results indicate that HAV and norovirus surrogates are sensitive to HPP treatments.
We have characterized the pressure levels and conditions required for virus inactivation. In response to increasing pressure, a first order logarithmic inactivation curve is generally observed for viruses. Characterization of the effects of extended treatment times indicates diminishing inactivation, or a “tailing” curve, as pressure treatment times are increased. Evaluation of temperature on virus inactivation by HPP indicates that for the norovirus surrogates, cold temperature (4 degree C) dramatically enhances inactivation by several orders of magnitude, while paradoxically for HAV, cold temperatures result in less inactivation. Direct demonstration of inactivation of bioconcentrated HAV within live oysters has been shown, as well as for HAV associated with green onions and strawberry puree. Characterization of the effects of NaCl and sucrose indicates that these solutes reduce the effectiveness of HPP on virus. Lower pH enhances inactivation of HAV while inactivation of the norovirus surrogate, FCV, is reduced. A human volunteer study to directly determine if human norovirus can be inactivated by HPP is ongoing.