PHYSICOCHEMICAL PROPERTIES OF COMMERCIAL GUMS AND THEIR EFFECTS ON PROCESSING AND COOKING QUALITY OF NONTRADITIONAL PASTA A Dissertation Submitted to the Graduate Faculty of the North Dakota State University of Agriculture and Applied Science By Gurleen Kaur Sandhu In Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Program: Cereal Science September 2012 Fargo, North Dakota North Dakota State University Graduate School Title Physicochemical Properties of Commercial Gums and Their Effects on Processing and Cooking Quality of Nontraditional Pasta By Gurleen Kaur Sandhu The Supervisory Committee certifies that this disquisition complies with North Dakota State University’s regulations and meets the accepted standards for the degree of DOCTOR OF PHILOSOPHY SUPERVISORY COMMITTEE: Dr. Frank Manthey Chair Dr. Senay Simsek Dr. Clifford Hall III Dr. Julie Garden-Robinson Approved: September 14, 2012 Dr. Deland Myers Date Department Chair ABSTRACT Processing characteristics and quality of pasta made from durum flour and semolina and the physicochemical properties of commercial gums and their effects on processing and cooking quality of nontraditional pasta were investigated. An initial experiment was conducted using semolina and durum flour fortified with nontraditional ingredients (soy flour or oat flour, 10% w/w) and xanthan, guar or locust bean gums (2% w/w). A second set of experiments were conducted to determine the effect of commercial source of food gums on their effect on the processing and cooking quality of nontraditional pasta. Proper hydration of nontraditional ingredient blends was more easily achieved with durum flour than semolina. Nontraditional ingredients tended to over-hydrate semolina resulting in large aggregates that adhered to metal surfaces, all of which made mixing and pasta processing difficult. Initially, dough strength was greater with durum flour than with semolina, but semolina had better dough stability over time. Soy and oat flours reduced dough strength. Xanthan and guar gums increased dough stability, particularly with durum flour. Pasta made with durum flour generally had greater cooking loss and lower cooked firmness than pasta made from semolina. Soy and oat flours reduced cooked firmness and increased cooking loss. Guar and locust bean gums did not affect cooking quality of pasta. Xanthan gum increased cooked firmness of pasta. Samples of each gum were obtained from three different commercial vendors. For each food gum, samples varied in bulk density, molecular weight, viscosity in distilled water and the magnitude of effect on dough strength with gum source. The effect of xanthan, guar and locust gums on hydration, dough strength, and cooking quality was not affected by the source. The iii magnitude of the increase in dough strength caused by xanthan and guar gums varied among their respective vendors. Results indicated that processing was easier with durum flour but pasta quality was better with semolina. Sources of gum did not influence the effect of gums on pasta processing or quality. Even though dough strength was affected, then in the end, no effect on the final pasta quality was observed. iv ACKNOWLEDGEMENTS I extend my deepest appreciation, respect and thanks to my major advisor, Dr. Frank A. Manthey, for his continuous guidance, encouragement, and support during the entire period of my study. My professional skills and personality benefitted immensely from his wisdom of knowledge, life-long experiences and scientific skills. I am equally thankful to the members of the advisory committee: Dr. Senay Simsek, Dr. Clifford Hall III and Dr. Julie-Garden Robinson for their valuable help and guidance from time to time. Special thanks to Dr. Richard Horsley for helping with statistical analysis. I am thankful to Mrs. Snigdharani Dash, Kristin Whitney and Brent Hinsz for their help in laboratory work. With sentiments of love, appreciation and deep sense of gratitude, I owe immensely to my loving and caring husband, Dr. Harkanwal preet Singh Sandhu, for his consistent, never- tiring help and encouraging support. Without him, this valuable venture of my life would have been very difficult. I feel blessed having an adorable 2-year-old son, Anhad Singh Sandhu, who rejuvenated our lives with his gentle touch, love and laughter. Words do not come in accordance with my feelings, which are deep in my heart for my loving parents, S. Surinder pal Singh Sandhu and Mrs. Sarbjit Kaur Sandhu for making me capable enough to achieve my goals in life. I am equally indebted to my parents-in-law, Dr. Bikkar Singh Sandhu and Mrs. Sukhwant Kaur Sandhu for their limitless love and support. I also thank my younger brother Gurtej Singh Sandhu, sister-in-law, Sukhwinder Kaur Sandhu and my cute-little nephew, Adeshinder Singh Sandhu. I also thank my sister-in-laws Gurinder Kaur and Rupinder Kaur and their families for their blessings and emotional support. My heart goes out in thanking my maternal and paternal grandmothers, Sardarni. Gurcharan Kaur Pannu, and Gurdeep Kaur Sandhu, respectively. v DEDICATION With immense feelings of respect and love, I would like to dedicate my dissertation to my late maternal and paternal grandfather’s, Sardar. Jaswant Singh Pannu and Sardar. Jaghminder Singh Sandhu, whom I miss every day and will never forget till last day of my life. vi TABLE OF CONTENTS ABSTRACT .......................................................................................................................... iii ACKNOWLEDGEMENTS ................................................................................................... v DEDICATION ...................................................................................................................... vi LIST OF TABLES .............................................................................................................. xiv LIST OF FIGURES ............................................................................................................ xvi LIST OF APPENDIX TABLES ....................................................................................... xviii FORMAT OF DISSERTATION ............................................................................................1 GENERAL INTRODUCTION ...............................................................................................2 Literature Cited ...........................................................................................................7 LITERATURE REVIEW .....................................................................................................11 Durum Wheat Grain ..................................................................................................11 Protein ...........................................................................................................14 Starch ............................................................................................................16 Lipids ............................................................................................................19 Non-starch Polysaccharides ..........................................................................20 Pasta ..........................................................................................................................20 Role of Semolina and/or Flour components in Pasta Making ..................................21 Semolina Proteins .........................................................................................21 Semolina Starch ............................................................................................23 Semolina Lipids ............................................................................................25 Nontraditional Pasta ..................................................................................................25 Soy in Pasta ...................................................................................................26 vii Oat in Pasta ...................................................................................................27 Food Gums in Pasta ..................................................................................................28 Galactomannans: Guar and Locust Bean Gum .............................................31 Xanthan Gum ................................................................................................33 Variation in the Functionality of Food Gums in Pasta Systems ...............................35 Literature Cited .........................................................................................................37 PAPER 1. QUALITY OF NONTRADITIONAL PASTA WHEN MADE WITH SEMOLINA AND WITH DURUM FLOUR ...........................................................50 Abstract .....................................................................................................................50 Introduction ...............................................................................................................51 Materials and Methods ..............................................................................................53 Materials .......................................................................................................53 Characterization of Ingredients and Blends ..................................................54 Swelling Volume ..............................................................................55 Approximate Water Holding Capacity .............................................55