Matrix Effect on Fat Crystallization in Laminated Bakery Products By
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Matrix Effect on Fat Crystallization in Laminated Bakery Products by Kristin Danielle Mattice A Thesis presented to The University of Guelph In partial fulfillment of requirements for the degree of Master of Science In Food Science Guelph, Ontario, Canada © Kristin Danielle Mattice, August, 2017 ABSTRACT Matrix Effect on Fat Crystallization in Laminated Bakery Products Kristin Danielle Mattice Advisor: University of Guelph, 2017 Dr. Alejandro G. Marangoni The impact of a croissant matrix on fat crystallization was determined by analyzing the polymorphism using powder x-ray diffraction (XRD), solid fat content (SFC) by pulsed nuclear magnetic resonance (p-NMR) and melting behaviour by differential scanning calorimetry (DSC). Roll-in shortenings of varying composition were used to prepare croissants. XRD revealed polymorphic conversion (from β' to the β form) occurs when fat is baked within the matrix, and the extent of conversion depends on the fat’s composition. In addition, the fat contained within a croissant will have a significantly lower SFC and a greater temperature is required for complete melting. The same fats were then baked in the presence of isolated croissant components (wheat starch, gelatinized wheat starch, gluten and a formed gluten network) and the cooled samples were analyzed using the same methods. Overall, the results suggested that changes in crystallization behaviour are caused by an interaction between fat and gelatinized wheat starch. ii ACKNOWLEDGEMENTS I would like to start by thanking my supervisor, Dr. Alejandro Marangoni, for all of his guidance over the past two years. He has been incredibly supportive and encouraging throughout this time, always pushing me to think, question and discuss. It is because of his continuous support and the positive environment he encourages in the lab that I am where I am today. I share my success with him, even though he never let me live down putting pineapple and bacon in chocolate. I would also like to thank my committee members, Dr. Douglas Goff and Dr. Amanda Wright, for willingly giving me their time, insight and support for the duration of my Master’s degree. Thank you for the constructive feedback and encouragement, your extensive knowledge has been so valuable to this project. To Dr. Fernanda Peyronel, Saeed Mirzaee Ghazani and Andrew Gravelle, I thank you for the advice, the help with equipment and for being friendly faces to rely on. To my lab mates, Katie, Brian, Pere, Cendy, Ming, Braulio, Chloe, Reed and the many visiting students that have come through, thank you for being true friends who are kind and enjoyable to be around. You are all responsible for the positive and respectful environment in the lab and it would not be the same without you. Finally, I would like to thank my family for their constant love and support. My parents, Susan and Mike, and my brother, Greg, who were always encouraging and were my biggest cheerleaders whenever I accomplished something new. And last but not least, my dog Finnie, who’s snuggling and companionship I could not live without. iii TABLE OF CONTENTS ABSTRACT ................................................................................................................................ ii ACKNOWLEDGEMENTS ....................................................................................................... iii TABLE OF CONTENTS ........................................................................................................... iv LIST OF TABLES .................................................................................................................... vii LIST OF FIGURES .................................................................................................................. viii LIST OF ABBREVIATIONS ..................................................................................................... x 1.0 Introduction ........................................................................................................................... 1 1.1 Objectives .................................................................................................................................... 3 1.2 Hypotheses .................................................................................................................................. 4 1.3 References ....................................................................................................................................... 5 2.0 Literature Review .................................................................................................................. 8 2.1 Introduction into Fat Crystallization ............................................................................................ 8 2.2 Properties of Laminating Shortenings ......................................................................................... 9 2.3 Laminated Doughs ..................................................................................................................... 10 2.4 Wheat Flour and its Components .............................................................................................. 12 2.4.1 Starch Retrogradation ........................................................................................................... 13 2.4.2 Lipid-Starch Interactions ...................................................................................................... 13 2.4.3 Lipid-Protein Interactions ..................................................................................................... 14 2.5 Challenges in Improving the Fatty Acid Profile of Roll-in Shortenings ................................... 15 2.5.1 Partial Solid Fat Replacement using Oleogels ...................................................................... 17 2.6 Conclusions ............................................................................................................................... 19 2.7 References ..................................................................................................................................... 21 iv 3.0 Part I: Matrix effects on the crystallization behaviour of butter and roll-in shortening in laminated bakery products ........................................................................................................ 28 3.1 Materials and Methods .................................................................................................................. 28 3.1.1 Materials ............................................................................................................................... 28 3.1.2 Fatty Acid (FA) Composition ................................................................................................ 28 3.1.3 Triacylglycerol (TAG) Compositions .................................................................................... 29 3.1.4 Croissant Preparation .......................................................................................................... 29 3.1.5 Baked Bulk Fats .................................................................................................................... 32 3.1.6 Polymorphism ....................................................................................................................... 32 3.1.7 Thermal Behaviour ............................................................................................................... 32 3.1.8 Solid Fat Content .................................................................................................................. 33 3.1.9 Texture Analysis .................................................................................................................... 33 3.1.10 Statistical Analysis .............................................................................................................. 34 3.2 Results and Discussion.................................................................................................................. 34 3.2.1 Fatty Acid Composition ........................................................................................................ 34 3.2.2 Triacylglycerol Composition ................................................................................................ 35 3.2.3 Polymorphism ....................................................................................................................... 37 3.2.4 Thermal Behaviour ............................................................................................................... 43 3.2.5 Solid Fat Content .................................................................................................................. 45 3.2.6 Texture Analysis .................................................................................................................... 47 3.3 Conclusions ................................................................................................................................... 48 3.4 References ..................................................................................................................................... 50 4.0 Part II: Gelatinized Wheat Starch Influences Crystallization Behaviour and Structure of Roll-in Shortenings in Laminated Bakery Products .................................................................. 53 4.1 Materials and Methods .................................................................................................................. 53 4.1.1 Materials ..............................................................................................................................