Purdue University Purdue e-Pubs Open Access Dissertations Theses and Dissertations January 2014 Fermentable Carbohydrate Substrates Generated from Cereal and Pseudocereal Insoluble Dietary Fibers and Their nI Vitro Fecal Fermentation Lisa Marcela Lamothe Purdue University Follow this and additional works at: https://docs.lib.purdue.edu/open_access_dissertations Recommended Citation Lamothe, Lisa Marcela, "Fermentable Carbohydrate Substrates Generated from Cereal and Pseudocereal Insoluble Dietary Fibers and Their nI Vitro Fecal Fermentation" (2014). Open Access Dissertations. 1499. https://docs.lib.purdue.edu/open_access_dissertations/1499 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Graduate School Form (Revised 0 8 /14) PURDUE UNIVERSITY GRADUATE SCHOOL Thesis/Dissertation Acceptance This is to certify that the thesis/dissertation prepared By Lisa Marcela Lamothe Entitled Fermentable Carbohydrate Sources Generated from Cereal and Pseudocereal Insoluble Dietary Fibers and Their In Vitro Fecal Fermentation Doctor of Philosophy For the degree of Is approved by the final examining committee: Bruce R. Hamaker Osvaldo H. Campanella Bradley L. Reuhs John Patterson To the best of my knowledge and as understood by the student in the Thesis/Dissertation Agreement, Publication Delay, and Certification/Disclaimer (Graduate School Form 32), this thesis/dissertation adheres to the provisions of Purdue University’s “Policy on Integrity in Research” and the use of copyrighted material. Bruce R. Hamaker Approved by Major Professor(s): Approved by: Brian Farkas 10/10/2014 Head of the Department Graduate Program Date 1 FERMENTABLE CARBOHYDRATE SUBSTRATES GENERATED FROM CEREAL AND PSEUDOCEREAL INSOLUBLE DIETARY FIBERS AND THEIR IN VITRO FECAL FERMENTATION A Dissertation Submitted to the Faculty of Purdue University by Lisa M Lamothe In Partial Fulfillment of the Requirements for the Degree of 1 Doctor of Philosophy December 2014 Purdue University West Lafayette, Indiana ii For my husband. tai ii iii ACKNOWLEDGEMENTS I would like to express my sincerest gratitude to Dr. Bruce Hamaker for his guidance, encouragement, and mentorship, and for thinking of me when he needed a student for this project. I would also like to thank Dr. Sathaporn Srichuwong for his valuable and constructive suggestions during the planning and development of this project. My gratitude also extends to the members of my advisory committee, Dr. Osvaldo Campanella, Dr. Bradley Reuhs, and Dr. John Patterson; and all the members of the Hamaker lab, especially, Haidi Xu, Amandeep Kaur, Tingting Chen, Choon Young Kim, and Anton Terekov. Finally, I would like to thank my husband, Estuardo Gómez, for his unconditional support and encouragement throughout these three and half years. iii iv TABLE OF CONTENTS Page LIST OF TABLES ........................................................................................................... viii LIST OF FIGURES ............................................................................................................ x ABSTRACT ..................................................................................................................... xiii INTRODUCTION .............................................................................................................. 1 Insoluble Dietary Fiber .................................................................................................. 3 Hypothesis and Specific Objectives ............................................................................... 3 CHAPTER 1. LITERATURE REVIEW ......................................................................... 5 1.1 Impact of Gut Microbiota on Health and Disease ................................................. 5 1.2 Dietary Fiber ......................................................................................................... 7 1.2.1 Dietary Fibers as Food Ingredients .................................................................. 8 1.2.2 Insoluble Dietary Fibers as Sources for Fermentable Fiber Substrates ........... 9 1.2.2.1 Sorghum (Sorghum bicolor) ..................................................................... 12 1.2.2.2 Pearl Millet (Pennisetum glaucum) .......................................................... 13 1.2.2.3 Amaranth (Amaranthus caudatus L.) ....................................................... 14 1.2.2.4 Quinoa (Chenopodium quinoa W.) .......................................................... 16 1.2.3 Modifications of Insoluble Dietary fibers to Generate Fermentable Carbohydrate Substrates ............................................................................................ 18 1.2.3.1 Hydrothermal Treatment .......................................................................... 19 iv 1.2.3.2 Enzymatic Hydrolysis .............................................................................. 22 1.3 Conclusions ......................................................................................................... 23 CHAPTER 2. QUANTIFICATION AND CHARACTERIZATION OF DIETARY FIBERS FROM ALTERNATIVE GRAINS .................................................................... 25 2.1 Abstract ............................................................................................................... 25 2.2 Introduction ......................................................................................................... 26 2.3 Materials and Methods ........................................................................................ 29 2.3.1 Cereal and Pseudocereal Grains .................................................................... 29 2.3.2 Insoluble and Soluble Fiber Contents ............................................................ 29 v Page 2.3.3 Development of an Isolation Procedure for Insoluble and Soluble Dietary fiber Fractions ............................................................................................................ 30 2.3.4 Compositional Analysis of Dietary Fiber Samples ....................................... 31 2.3.5 Monosaccharide and Glycosyl-linkage Composition of Dietary Fiber Samples ....................................................................................................................... 32 2.3.6 Data Analysis ................................................................................................. 33 2.4 Results and Discussion ........................................................................................ 33 2.4.1 Determination of Dietary Fiber Contents in Alternative Grains ................... 33 2.4.2 Isolation of Insoluble and Soluble Dietary Fibers from Alternative Grains .. 35 2.4.3 Chemical Composition of Isolated Insoluble and Soluble Dietary Fibers from Alternative Grains ...................................................................................................... 36 2.4.4 Monosaccharide and Glycosyl-linkage Composition of Insoluble and Soluble Dietary Fibers from alternative Grains ...................................................................... 38 2.4.4.1 Pseudocereals: Quinoa and Amaranth ...................................................... 38 2.4.4.2 Cereals: Sorghum and Pearl Millet .......................................................... 44 2.4.4.3 Cereals: Wheat and Maize ........................................................................ 47 2.5 Conclusions ......................................................................................................... 48 CHAPTER 3. SOLUBILIZATION OF INSOLUBLE DIETARY FIBERS BY HYDROTHERMAL TREATMENTS AND ENZYMATIC HYDROLYSIS ................. 60 3.1 Abstract ............................................................................................................... 60 3.2 Introduction ......................................................................................................... 61 3.3 Materials and Methods ........................................................................................ 63 3.3.1 Development of Hydrothermal Treatments of Insoluble Dietary Fibers ....... 63 3.3.1.1 Liquid hot water treatment ....................................................................... 63 3.3.1.2 Autoclave treatment ................................................................................. 64 3.3.1.3 Microwave radiation treatment ................................................................ 64 v 3.3.2 Development of a Sequential Enzymatic Hydrolysis of Hydrothermally- Treated Insoluble Dietary Fibers ............................................................................... 65 3.3.2.1 Enzyme Hydrolysis A .............................................................................. 66 3.3.2.2 Enzyme Hydrolysis B ............................................................................... 66 3.3.2.3 Enzyme Hydrolysis C ............................................................................... 67 3.3.3 Determination of Soluble Carbohydrate Content .......................................... 67 3.3.4 Characterization of Solubilized Fiber Oligosaccharides ............................... 68 3.4 Results and Discussion ........................................................................................ 69 3.4.1 Development of a Solubilization Procedure for Insoluble Dietary Fibers .... 69 3.4.1.1 Pseudocereals: Quinoa and Amaranth .....................................................