2012 Annual Report
1a.Objectives (from AD-416):
Objective 1: To determine whether an in vitro cultivable enteric monkey calicivirus, the Tulane virus, can be used as a surrogate for human NoV and to develop an organ culture and/or germ-free pig model to assess the survival of human NoV (Jiang, Li and Lee).
Objective 2. To determine the effectiveness of four processing technologies (viz., high pressure processing, gamma irradiation, UV, and washing with sanitizers) on inactivation of human NoV, HAV and RV in, fresh and frozen berries (strawberries, raspberries and blueberries), berry purees, green onions, salsa and shellfish (Gurtler and Niemira).
Objective 3. To determine the mechanism of viral inactivation by the four processing technologies. We will investigate whether viral capsid proteins, viral enzymes, genetic materials, and receptor binding activity are damaged or denatured by the processing technologies. (Jiang, Li, Lee, Chen, Wu, and Ozbay)
Objective 4. To determine the effect of processing on the quality attributes of high risk foods. Sensory quality, important nutrients in the high risk foods, color, texture, and other important properties will be evaluated (Su, Chen, Wu, and Ozbay).
Objective 5. To train graduate and undergraduate students in non-thermal processing technologies, food virology, and food safety; and to develop a “Foodborne Viruses and Food Safety” course and food virus module for classroom education nationwide (Chen, Wu, and Ozbay).
Objective 6. To work with equipment manufacturers to design appropriate equipment for use in the targeted food products and to provide technical consultation to the food industry (Su, Chen, Wu, and Ozbay).
Objective 7. To provide outreach education and training to the food industry and consumers in the area of foodborne viruses and food safety impacts of non-thermal technologies on high risk foods (Worobo and Pivnarik).
1b.Approach (from AD-416):
Contribute expertise related to gamma irradiation, high pressure processing, microbiology and food science, lab supplies and associated equipment. Collaborating universities will contribute to experiments, administer funds, hire and equip temp employee(s) and students in their campus labs, and coordinate the project.
USDA-ARS, FSIT will undertake the research objective stated above. This will be accomplished by: Determining the effectiveness of four processing technologies (viz., high pressure processing, gamma irradiation, UV, and washing with sanitizers) on inactivation of human NoV, HAV and RV in fresh and frozen berries (strawberries, raspberries and blueberries), berry purees, green onions, salsa and shellfish.
a. High pressure processing, and gamma irradiation in combination with GRAS antimicrobials will be evaluated for the elimination of human NoV, HAV and RV in fresh and frozen berries (strawberries, raspberries and blueberries), berry purees, green onions, salsa and shellfish. A greater than or equal to 5-log reduction will be tested at 700 MPa for 2, 4, 6, 8, 10, 12, and 14 min, 750 MPa for 1, 2, 3, 4, 5, 5, and 7 min, and 800 MPa for 0.5, 1, 1.5, 2, 2.5, 3, and 3.5 min. Gamma irradiation will be in dose ranges of 0 (control), 0.25, 0.5, 0.75, 1.0, 1.5, 2.0 kGy.
During FY 2012, ARS scientists in Wyndmoor, PA worked with collaborators from The Ohio State University and the University of Delaware to determine the sensitivity of norovirus virus-like particles to high pressure processing. Results revealed that the norovirus virus-like particles are highly pressure-resistant, and are only destroyed at pressures as high as 800 and 900 MPa; thus, norovirus virus-like particles may potentially serve as non-pathogenic surrogates for norovirus in studies where the virulent virus cannot be utilized. ARS scientists in Wyndmoor, PA also identified a post-doctoral research candidate who has agreed to come to the USDA, ARS in Wyndmoor, PA and work for 2-years on the USDA research responsibilities for this grant. The post-doctoral researcher will begin work in October, 2012.