AN INITIATIVE TO CLEAN LABEL: CAN WE REPLACE DOUGH STRENGTHENERS IN BREAD FORMULATIONS A Thesis Submitted to the Graduate Faculty of the North Dakota State University of Agriculture and Applied Science By Md Mahfuzur Rahman In Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE Major Program: Cereal Science April 2018 Fargo, North Dakota North Dakota State University Graduate School Title AN INITIATIVE TO CLEAN LABEL: CAN WE REPLACE DOUGH STRENGTHENERS IN BREAD FORMULATIONS By Md Mahfuzur Rahman The Supervisory Committee certifies that this disquisition complies with North Dakota State University’s regulations and meets the accepted standards for the degree of MASTER OF SCIENCE SUPERVISORY COMMITTEE: Dr. Senay Simsek Chair Dr. Frank Manthey Dr. Jae-Bom Ohm Dr. Xinhua Jia Approved: May 02, 2018 06 Dr. Richard D. Horsley Date Department Chair ABSTRACT Dough strengtheners are the most common and largest group of chemicals used in bread formulations. This study evaluated the capability of hard red spring (HRS) wheat flour to replace commercial dough strengtheners in bread production. Doughs were prepared by blending different percentages (10%, 20%, 30% and 40%) of four different HRS wheat flours with hard red winter (HRW) wheat flour. In addition, doughs were prepared by adding ten commercially available additives with HRW wheat flour to compare the dough strengthening ability of HRS wheat flour. All the HRS wheat flour blends had significantly (p<0.05) strong dough rheological characteristics than most of the additives. The 40% blends of HRS wheat cultivar Glenn and Linkert had better bread making quality than other blends and all the additives. The SE-HPLC unextractable protein fractions of these two cultivars also showed a better correlation with bread making properties than all the additives. iii ACKNOWLEDGEMENTS First and foremost, I would like to thank my advisor and mentor, Dr. Senay Simsek. Thank you very much for accepting me as your student and for your never-ending guidance, encouragement, and support throughout my study. My appreciation extends to all members of my graduate committee: Dr. Frank Manthey, thank you for your advice and support throughout this study and especially writing. Dr. Jae-Bom Ohm, thank you for welcoming me to your laboratories, for your assistance in the statistical analysis and data interpretation. Dr. Xinhua Jia, thank you for your kindness, valuable inputs, and support. Special acknowledgment to DeLane Olsen for her technical assistance and support throughout my thesis experiments. I would also like to acknowledge Kristin Whitney and Stephanie Ness for their technical assistance and support. My thanks extend to my lab-mates, office-mates, and friends for their help and support. My gratitude feelings towards my parents and siblings couldn’t express in words for their support, encouragement, and mentorship, which has helped me immensely in all aspects of my life. Finally, my heartfelt appreciation to my wife Ferdows Ara Parvin, for her patience, inspiration, and support for my graduate education. iv DEDICATION I would like to dedicate this dissertation to my parents who has sacrificed a lot for my education. v TABLE OF CONTENTS ABSTRACT ................................................................................................................................... iii ACKNOWLEDGEMENTS ........................................................................................................... iv DEDICATION ................................................................................................................................ v LIST OF TABLES ......................................................................................................................... ix LIST OF FIGURES ........................................................................................................................ x LIST OF APPENDIX TABLES .................................................................................................... xi LIST OF APPENDIX FIGURES.................................................................................................. xii GENERAL INTRODUCTION ....................................................................................................... 1 Overall Objectives ....................................................................................................................... 3 Need Statement ........................................................................................................................... 3 References ................................................................................................................................... 4 CHAPTER 1. LITERATURE REVIEW ........................................................................................ 6 1.1. Bread Production .................................................................................................................. 6 1.2. Ingredients Used in Bread Formulations .............................................................................. 7 1.2.1. Major ingredients used in bread formulations ............................................................... 8 1.2.2. Minor ingredients .......................................................................................................... 9 1.2.3. Micro ingredients......................................................................................................... 10 1.2.4. Bakery improvers ........................................................................................................ 10 1.2.5. Functions dough strengtheners and reaction with protein ........................................... 13 1.2.6. Effect dough additives on dough rheology and loaf volume ....................................... 14 1.3. Health Effect and Controversies with Dough Strengtheners.............................................. 19 1.4. What is Clean Label? ......................................................................................................... 20 1.4.1. What makes a clean label? .......................................................................................... 20 1.4.2. Ingredient selection for clean label .............................................................................. 22 vi 1.5. Wheat Flour Protein and Bread Quality ............................................................................. 23 1.5.1. Dough strengtheners and protein molecular weight .................................................... 26 1.5.2. Protein Molecular weight distribution by SE –HPLC and bread quality .................... 27 1.6. References .......................................................................................................................... 30 CHAPTER 2. REPLACEMENT OF COMMERCIAL DOUGH STRENGTHENERS WITH HARD RED SPRING WHEAT FLOUR .......................................................................... 39 2.1. Abstract .............................................................................................................................. 39 2.2. Introduction ........................................................................................................................ 40 2.3. Materials and Methods ....................................................................................................... 42 2.3.1. Sampling ...................................................................................................................... 42 2.3.2. Proximate composition of flours, dough, and bread crumbs ....................................... 44 2.3.3. Dough rheology measurement ..................................................................................... 44 2.3.4. Baking and bread quality ............................................................................................. 45 2.3.5. Bread firmness ............................................................................................................. 45 2.3.6. Statistical analysis ....................................................................................................... 45 2.4. Results and Discussion ....................................................................................................... 46 2.4.1. Proximate analysis of flour, dough, and bread crumb ................................................. 46 2.4.2. Effect of HRS wheat blends and additives on dough rheology ................................... 46 2.4.3. Correlation between farinograph and extensograph data ............................................ 53 2.4.4. Quality traits of the bread made of HRS wheat flour blends and additives ................ 54 2.4.5. Correlation between dough rheology and bread quality characteristics ...................... 64 2.5. Conclusions ........................................................................................................................ 66 2.6. References .......................................................................................................................... 67 CHAPTER 3. MOLECULAR WEIGHT DISTRIBUTION OF PROTEIN EXTRACTED FROM DOUGH AND BREAD MADE OF HRS WHEAT BLEND AND ADDITIVES, AND ITS CORRELATION WITH DOUGH AND BREAD CHARACTERISTICS ................. 73 vii 3.1. Abstract .............................................................................................................................. 73 3.2. Introduction .......................................................................................................................