At the Thursday morning scientific session 244 The Emerging Viral Threat: Novel Processing Technologies to Control Norovirus in Foods, researchers from several universities discussed various ongoing studies to inactivate norovirus in foods. These studies are being funded by the U.S. Dept. of Agriculture/National Institute of Food and Agriculture (NIFA).
Noroviruses are very different than bacteria, said Doris D’Souza, Ph.D., Assistant Professor, Univ. of Tenn.-Knoxville. They are intracellular parasites, persistent in the environment, resistant to mild processes, and are infectious at low doses. Noroviruses can be transmitted fecal to oral, through contaminated food/water, and person to person. The primary foods of concern are shellfish, raw fruits and vegetables, and ready-to-eat foods. About 5.5 million cases of norovirus-related illness occur annually in the United States. D’Souza’s work involves thermal inactivation studies of human virus surrogates.
Jennifer Cannon, Ph.D., Univ. of Georgia, discussed her work on hurdle technologies to reduce the risk of norovirus in meat processing and retail operations. The goal of the research is to improve food safety, maintain product quality, and develop technologies that are economically feasible for use in food processing plants, noted Cannon. She reviewed studies on the use of electrolyzed oxidizing water (low pH) and a levulinic acid for reducing norovirus on food processing surfaces and on food handler gloves.
Shyam Sablani, Ph.D., Assistant Professor, Wash. State Univ., presented an update on the pilot-scale 915 MHz single-mode microwave pasteurization system, which should be available for testing by the end of the year. Some of that testing will involve thermal destructive kinetics of selective viruses.
Haiqiang Chen, Ph.D., Assistant Professor, Univ. of Delaware, presented data on the use of nonthermal processes to inactivate human surrogate noroviruses. Research has shown that lower temperature high-pressure processing performed better than higher temperatures in inactivating the surrogates. In a study on high-pressure processing of blueberries, virus-inoculated blueberries in a buffer solution were more sensitive to the pressure treatment than dry blueberries.