Survival of Human Norovirus Surrogates in Juices and Their Inactivation Using Novel Methods
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University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Masters Theses Graduate School 5-2011 Survival of Human Norovirus Surrogates In Juices and their Inactivation Using Novel Methods Katie Marie Horm [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_gradthes Recommended Citation Horm, Katie Marie, "Survival of Human Norovirus Surrogates In Juices and their Inactivation Using Novel Methods. " Master's Thesis, University of Tennessee, 2011. https://trace.tennessee.edu/utk_gradthes/882 This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Katie Marie Horm entitled "Survival of Human Norovirus Surrogates In Juices and their Inactivation Using Novel Methods." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Master of Science, with a major in Food Science and Technology. Doris H. D'Souza, Major Professor We have read this thesis and recommend its acceptance: Federico M. Harte, Gina M. Pighetti Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Survival of Human Norovirus Surrogates In Juices and their Inactivation Using Novel Methods A Thesis Presented for the Master of Science Degree The University of Tennessee, Knoxville Katie Marie Horm May 2011 Acknowledgments I would like to think my major professor/advisor Dr. Doris D’Souza for her help and giving me the opportunity to complete my M.S. degree. With her continual challenges to go beyond what was expected has provided me with a much appreciated educational experience. For that, I am greatly appreciative to have worked under her for these last two years. I would also like to thank Xiaowei Su, Chayapa Techathuvanan, and Robb Davis for their encouragement and friendship. They both are a remarkable friend that has always been there to guide me and for that I am truly grateful. I would like to express my appreciation to my committee members, Dr. Federico Harte and Dr. Gina Pighetti for their input and challenges. To the Food Science Department, thanks for all the great times and laughs that we have shared. The faculty, staff, and students are among the best showing great enthusiasm and openness to everyone. This is just one of the many great qualities about this department that makes it one of the best. Last, but certainly not least, I would like to thank my family for their endless support. ii ABSTRACT Human noroviruses (HNoV) have been implicated in gastrointestinal outbreaks associated with fruits and juices. Virus survival studies and non-thermal inactivation technologies that maintain nutritional and sensory attributes of juices are needed. In the absence of culturable HNoV, cultivable murine norovirus (MNV-1) and feline calicivirus (FCV-F9) surrogates are used. This study aimed to (1) determine HNoV surrogate survival in juices (orange juice (OJ) and pomegranate juice (PJ)), juice blends (OJ-PJ), and milk over 21 days at refrigeration; (2) determine high pressure homogenization (HPH) effects alone on HNoV surrogates in milk, OJ, OJ-PJ blend or with an emulsifier (lecithin) for FCV-F9 and MNV-1 in milk and OJ; (3) determine HNoV surrogate survival in blueberry juice (BJ) after 21 days at refrigeration and HPH inactivation. Our results showed no reduction of MNV-1 after 21 days in OJ and milk, but 1.4 log reduction in PJ and complete reduction after 7 days in OJ-PJ. FCV-F9 was completely reduced after 14 days in OJ and PJ; by ~3 logs after 21 days in milk, and completely reduced after 1 day in OJ-PJ. MS2 was reduced by ~1.28 log in OJ and <1 log in milk, PJ, or OJ-PJ after 21 days. At 300 MPa HPH, FCV-F9 in milk and OJ was reduced by ≥4 log10PFU/ml and MNV-1 in milk by ~1.3 log and negligibly in OJ. In PJ-OJ, FCV-F9 was completely reduced at 250 MPa. At 300 MPa in PJ-OJ, MNV-1 and MS2 showed 1.78 and 4.1 log10PFU/ml reduction. FCV-F9 showed complete reduction in OJ or milk combined with lecithin at 300 MPa. Thus, juice-blends and lecithin aid in viral reduction by HPH. In BJ, FCV-F9 was undetectable after 1 day while MNV-1showed minimal reduction after 21 days and MS2 was undetectable after 7 days. FCV-F9, MNV-1, and MS2 survived after 21 days in PBS. FCV-F9 and MS2 showed complete reduction after minimal homogenization pressures in BJ. Overall, milk was the most protective media for HPH and virus survival. These viral survival patterns that aid in foodborne viral transmission can be used in quantitative viral risk assessment studies along with HPH to prevent/control virus outbreaks. iii TABLE OF CONTENTS CHAPTER PAGE I. Literature Review..............................................................................................................1 Human Enteric Viruses..............................................................................................1 Processing Methods for Foodborne Viral Inactivation .............................................2 Foodborne Virus Survival .......................................................................................26 Natural Plant Polyphenols for Foodborne Viral Inactivation ..................................29 References ...............................................................................................................37 Appendix .................................................................................................................55 II. Survival of Human Norovirus Surrogates in Milk, Orange and Pomegranate Juice, and Juice Blends at Refrigeration (4°C) .........................................................................78 Abstract ...................................................................................................................79 Introduction .............................................................................................................80 Materials and Methods ............................................................................................82 Viruses and Cell Lines .....................................................................................82 Virus Propagation and Preparation ..................................................................82 Infectious Plaque Assays .................................................................................83 MS2 Plaque Assay ...........................................................................................83 Survival Study ..................................................................................................84 Statistical Analysis ...........................................................................................84 Results .....................................................................................................................85 Survival Charcteristics of FCV-F9 in Milk, Orange Juice, and Pomegranate Juice over 21 Days at Refrigeration Temperature (4°C)............85 Survival Charcteristics of MNV-1 in Milk, Orange Juice, and Pomegranate Juice over 21 Days at Refrigeration Temperature (4°C)............85 Survival Charcteristics of MS2 in Milk, Orange Juice, and Pomegranate Juice over 21 Days at Refrigeration Temperature (4°C) .................................86 Survival Charcteristics of FCV-F9, MNV-1, and MS2 in Pomegranate Juice and Pomegranate Polyphenol Diluted in PBS over Time at 4°C ...........86 Survival Charcteristics of FCV-F9, MNV-1, and MS2 in Blends of Orange Juice and PBS, Orange Juice and Pomegranate Juice or Orange Juice and Pomegranate Polyphenols ................................................................87 Discussion ...............................................................................................................88 Acknowldegements .................................................................................................97 References ...............................................................................................................98 Appendix ...............................................................................................................102 III. Application of High Pressure Homogenization for the Inactivation of Human Norovirus Surrogates in Milk, Orange Juice, and Pomegranate Juice Blends .............115 Abstract .................................................................................................................116 Introduction ...........................................................................................................117 Materials and Methods ..........................................................................................120 Viruses and Cell Lines ...................................................................................120 FCV-F9 Plaque Assay....................................................................................121 MNV-1 Plaque Assay ....................................................................................121 MS2 Plaque Assay .........................................................................................122 Preparation of Lecithin ..................................................................................122