University of Vermont ScholarWorks @ UVM Graduate College Dissertations and Theses Dissertations and Theses 2017 Development and Implementation of Methods to Study Crystallization in Cheese Gil Fils Tansman University of Vermont Follow this and additional works at: https://scholarworks.uvm.edu/graddis Part of the Food Science Commons Recommended Citation Tansman, Gil Fils, "Development and Implementation of Methods to Study Crystallization in Cheese" (2017). Graduate College Dissertations and Theses. 747. https://scholarworks.uvm.edu/graddis/747 This Dissertation is brought to you for free and open access by the Dissertations and Theses at ScholarWorks @ UVM. It has been accepted for inclusion in Graduate College Dissertations and Theses by an authorized administrator of ScholarWorks @ UVM. For more information, please contact [email protected]. DEVELOPMENT AND IMPLEMENTATION OF METHODS TO STUDY CRYSTALLIZATION IN CHEESE A Dissertation Presented by Gil Tansman to The Faculty of the Graduate College of The University of Vermont In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Specializing in Animal, Nutrition, and Food Sciences May, 2017 Defense Date: March 21, 2017 Dissertation Examination Committee: Paul S. Kindstedt, Ph.D., Advisor John M. Hughes, Ph.D., Chairperson Catherine, W. Donnelly, Ph.D. Douglas J. Taatjes, Ph.D. Cynthia J. Forehand, Ph.D., Dean of the Graduate College ABSTRACT Dissolved compounds and ions, including mineral elements and products of microbial metabolism, are present in many cheeses in relatively high concentrations. These dissolved substances may precipitate from the aqueous phase of cheese to form sparingly soluble crystals that can impart a crunchy, gritty, or sandy texture on the cheese. In the present work, optical and diffractometric methods were optimized for use with cheese samples to identify crystal phases in several cheese varieties. These techniques, which included powder X-ray diffractometry (PXRD), single crystal X-ray diffractometry (SCXRD), and petrographic microscopy (PM) have traditionally been used on geological specimens that are quite different from the cheese samples used in the present study. Nonetheless, these techniques were successfully used to gain valuable insight into crystal development in cheese. Powder X-ray diffractometry was optimized to minimize the occurrence of artifacts that may occur due to the high water content and low crystallinity of some cheese samples. The use of enhanced sample preparation techniques facilitated the identification of organic and inorganic crystal phases such as tyrosine, leucine, brushite (CaHPO4·2H2O), and calcite (CaCO3) in hard and soft cheeses. SCXRD was used to determine the crystal structures of ikaite and struvite, which had been tentatively identified in washed-rind cheese using PXRD. PM was used to observe morphological and optical properties of crystals in white mold cheese and washed-rind cheese. In two subsequent aging studies, PXRD was used to determine the approximate timing of crystal nucleation in the rinds of white mold cheese and washed-rind cheese. These observations were paired with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) data to demonstrate that the onset of crystallization in the rinds coincided with a diffusion phenomenon in which mineral ions diffused from the center of the cheese and became concentrated in the rind. PM observations demonstrated that maximum crystal size in the rinds generally increased as aging progressed. These observations will be useful in future work that investigates the impact of crystallization on sensory properties of cheese. CITATIONS Material from this dissertation has been published in the following form: Tansman, G., P. S. Kindstedt, and J. M. Hughes. (2015). Crystal fingerprinting: elucidating the crystals of Cheddar, Parmigiano-Reggiano, Gouda, and soft washed-rind cheeses using powder x-ray diffractometry. Dairy Science and Technology 95(5):651- 664. Material from this dissertation has been accepted for publication in The Canadian Mineralogist on August 22, 2016 in the following form: Tansman, G., P. S. Kindstedt, and J. M. Hughes. (2015). Minerals in food: crystal structures of ikaite and struvite from bacterial smears on washed rind cheese. The Canadian Mineralogist. Material from this dissertation has been accepted for publication in the Journal of Dairy Science on March 29, 2017 in the following form: Tansman, G., P. S Kindstedt, and J. M. Hughes. Crystallization and demineralization phenomena in stabilized white mold cheese. Journal of Dairy Science. ii ACKNOWLEDGEMENTS I would like to dedicate this dissertation to my faculty mentors at the University of Vermont who guided me through this endeavor. I am forever indebted to Dr. Paul Kindstedt, who introduced me to the world of scientific research as a Master’s student and mentored me through my doctoral studies as well. I have strived to make Dr. Kindstedt’s distinct style of scientific reasoning my own and after hundreds of hours of instruction, he has left an indelible and durable impression. I must recognize Dr. John Hughes for his friendship and for his tutelage in the complex and delightful study of crystallography. Witnessing Dr. Hughes’ incredible ability to integrate the study of Food Science into his extensive expertise has inspired me to seek insight and knowledge wherever available. I offer my sincere gratitude to Dr. Catherine Donnelly and Dr. Douglas Taatjes for challenging the limits of my understanding in their disciplines. To my parents, who treasure knowledge and are the foundation upon which my scientific undertakings and achievements are built. And to my wife and life partner, Serach Eladia, whose energy and grace are inspiration for every idea and meditation. iii TABLE OF CONTENTS Citations .............................................................................................................................. ii Acknowledgements ............................................................................................................ iii List of Tables ................................................................................................................... viii List of Figures .................................................................................................................... ix Chapter 1: Comprehensive Literature Review .....................................................................1 Introduction ............................................................................................................................ 1 Texture Development During the Ripening of Traditional White Mold Cheese ................... 1 Factors Affecting White Mold Cheese Softening .................................................................. 1 Effect of Moisture Content on Texture Development ........................................................... 2 Effect of Microbial Growth on pH ........................................................................................ 4 Factors Affecting Casein Hydration ...................................................................................... 6 Proteolysis and Texture Development ................................................................................... 7 Production of Metabolic Gases .............................................................................................. 9 Dynamic Between P. camembertii and G. candidum .......................................................... 10 Effects of Temperature on Metabolic Activities.................................................................. 11 Diffusion of Calcium and Phosphate ................................................................................... 12 Interrelatedness of Softening Processes ............................................................................... 13 Effect of O2 and CO2 on White Mold Cheese Texture Development .................................. 15 Aerobic Respiration of White Mold Cheese Microbes ........................................................ 15 Effect of Headspace Carbon Dioxide on Ripening .............................................................. 16 Rind Texture Defects Under Elevated Headspace Carbon Dioxide .................................... 17 Stimulation of Under-Rind Development by Headspace Carbon Dioxide .......................... 18 Impact of Packaging on Cheese Ripening During Cold Storage ......................................... 19 Carbonate and Phosphate Mineral Phase Formation and Transformation ........................... 22 Thermodynamic and Kinetic Stability of Crystal Phases .................................................... 22 Effect of pH on Calcium Phosphate Stability ...................................................................... 23 Precipitation of Metastable Calcium Phosphate .................................................................. 25 Effect of Additives on Metastable Calcium Phosphate Phases ........................................... 27 Factors Effecting the Precipitation of Calcium Carbonate Phases ...................................... 29 2- CO3 Concentration and Carbonate Supersaturation .......................................................... 32 Kinetic Inhibition of Calcite by Dissolved Additives .......................................................... 34 Precipitation of Metastable Carbonates in the Presence of Additives ................................. 37 Precipitation of Ikaite in the Absence