Risk Management of Aflatoxin Through Mutagenic Potential Modification and Toxin Formation by Intrinsic Components in Food
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Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1999 Risk Management of Aflatoxin Through Mutagenic Potential Modification and Toxin Formation by Intrinsic Components in Food. Syed Shahid Ali Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Ali, Syed Shahid, "Risk Management of Aflatoxin Through Mutagenic Potential Modification and Toxin Formation by Intrinsic Components in Food." (1999). LSU Historical Dissertations and Theses. 7034. https://digitalcommons.lsu.edu/gradschool_disstheses/7034 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. 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Photographs included in tfie original manuscript have been reproduced xerographically in this copy. Higher quality 6" x9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. Bell & Howell Information and Leaming 300 North Zeeb Road, Ann Arbor, Ml 48106-1346 USA UMJ800-521-0600 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. RISK MANAGEMENT OF AFLATOXIN THROUGH MUTAGENIC POTENTIAL MODIFICATION AND TOXIN FORMATION BY INTRINSIC COMPONENTS IN FOOD A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy m The Department of Food Science by Syed Shahid Ali B. Sc. University o f Agriculture, Faisalabad-Pakistan, 1988 M S., North Carolina State University, 1995 December 1999 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number 9951594 UMI UMI Microform9951594 Copyright 2000 by Bell & Howell Information and Leaming Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. Bell & Howell Information and Leaming Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1348 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. For my parents ‘Wealth and Children are the adornment ofthis present life: but good works, which are lasting are better in the sight o f thy Lord as to recompense, and better as to hope (Qur’an 18:46) 11 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGEMENTS The author wishes to express his sincere gratitude and deepest appreciation to all of those who contributed towards the completion of this project. Special gratitude is due to Dr. Douglas L. Park, my mentor and the Director of Food Toxicology Research Group, whose consistent encouragement, constant support and guidance helped me to understand the importance of aflatoxin, but most of all to prepare me to take on the challenges in science. Special appreciation is extended to Dr. Vincent L. Wilson, for his invaluable advice, guidance and input in reviewing my dissertation script. My appreciation is also due to Dr. Wanda Lyon, Dr. Joan King. Dr. Leslie Plhak and Dr. Mark Neer, members of my graduate committee, for reviewing this dissertation and extending their help and knowledge. The completion of this project would not have been possible without the input of all those people who contributed their resources, technical support and knowledge. Special acknowledgements are due to Dr. Bruce Ames (University of California, Berkley), for providing the bacterial tester strains and technical assistance; Dr. Kenneth Damann and Dr. Ray Schneider (LSU Department of Plant Pathology), for extending their resources during the storage study of com; Mr. Hershchel Morris and Dr. Janet Simonson (LSU Agricultural Chemistry), for their technical assistance in the use of HPLC; Dr. Mary Trucksess, FDA, Washington, for providing purified toxins; Mr. Yu Kang (graduate student) and Dr. Kayambi, (LSU Dept, of Plant pathology), for preparations in carrying out the 111 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. storage study; Mr. Mike Hooks Q.SU campus safety^ office), for their invaluable assistance in the safe handling o f toxic reagents during this research. Special gratitude is extended to the FTRG team, Mr. (Dr.) Henry Njapau, Dr. Rebeca Lopez-Garcia, Dr. Armando Burgos-Hemandez, and Mrs. Dennise Craig, for sharing their knowledge and technical skills through discussions during the course of this research but, most of all, making the toxicology laboratory, a better place to work. No words can express my gratitude to Ms. Yuri P. Weydling, for sharing my good and bad times in and outside the lab. throughout the course o f this study and helping me to prepare this document but most of all, her friendship. My appreciation is also due to all the students in the department and people in the administration of the department of Food Science, for extending their emotional and moral support during my stay in the department. I also wish to thank Dr. Hameed Bajwai, Director General, Balochistan Agriculture Research Institute, Quetta-Pakistan, for his continual support in my academic persuit; and the team of World Bank Consortium, Pakistan for their financial support. Finally, I wish to express my infinite gratitude to my parents, my family, and my fiiends in the United States of America and in Pakistan. I would not be what I am without their love, moral and emotional support. IV Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS DEDICATION........................................................................................................ ü ACKNOWLEDGEMENTS..................................................................................üi LIST OF TABLES................................................................................................. ix LIST OF FIGURES .......................................................... jc ABSTRACT..........................................................................................................xiv 1. INTRODUCTION.............................................................................................. 1 2. LITERATURE REVIEW .................................................................................. 7 A. Historical Background........................................................................ 7 B. Aflatoxins..............................................................................................9 1. Discovery................................................. 9 2. Mycology and Occurrence ...................................................13 3. Toxin Production................................................................. 16 4. Chemical Characteristics ................................................17 5. Metabolism ........................................................................... 19 a. Absorption and distribution ..................................... 19 b. Phase I metabolism ...................................................20 c. Phase II metabolism ..................................................24 d. Competitive pathways: activation and detoxification ............. 25 6 . T oxicity ................................................................................. 27 C. Detoxification/Decontamination Procedures for Aflatoxin 29 1. Physical Degradation ...........................................................30 2. Chemical Degradation .........................................................31 3. Biological Degradation ........................................................33 D. Other Risk Management Procedures for Aflatoxin ......................... 38 E. Cancer and its Prevention 39 F. Food and Chemopreventors/Anti-mutagens ....................................43 1. Chemopreventors and Their Mechanisms of Action 47 a. Plant polyphenols 48 • b. Vitamins ,....... 51 c. Soybean effect 54 d. Fiber and phytic acid ........................................ 54 e. Polyunsaturated fatty acids.....................................