Effects of Harvest Conditions and Thickness Fractionation On
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University of Arkansas, Fayetteville ScholarWorks@UARK Theses and Dissertations 12-2016 Effects of Harvest Conditions and Thickness Fractionation on Physicochemical Properties, Cooking and Sensory Characteristics of Long Grain Rice Sara Esther Jarma Arroyo University of Arkansas, Fayetteville Follow this and additional works at: http://scholarworks.uark.edu/etd Part of the Agronomy and Crop Sciences Commons, and the Food Processing Commons Recommended Citation Jarma Arroyo, Sara Esther, "Effects of Harvest Conditions and Thickness Fractionation on Physicochemical Properties, Cooking and Sensory Characteristics of Long Grain Rice" (2016). Theses and Dissertations. 1826. http://scholarworks.uark.edu/etd/1826 This Thesis is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of ScholarWorks@UARK. For more information, please contact [email protected], [email protected]. Effects of Harvest Conditions and Thickness Fractionation on Physicochemical Properties, and Cooking and Sensory Characteristics of Long Grain Rice A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Food Science by Sara Esther Jarma Arroyo Universidad de Córdoba Bachelor of Science in Food Engineering, 2014 December 2016 University of Arkansas This thesis is approved for recommendation to the Graduate Council. _______________________________ Dr. Han-Seok Seo Thesis Director _______________________________ Dr. Jean-François Meullenet Committee member _______________________________ Dr. Paul Counce Committee Member _______________________________ Dr. Terry Siebenmorgen Committee Member Abstract Previous research has demonstrated the extensive impacts of various environmental and processing conditions on rice milling and processing characteristics. Nevertheless, little is known about the influences of these conditions on cooking and sensory qualities of rice. The present study aimed to determine the impact of cultivating location, harvest moisture content (HMC), and thickness fractionation on the physicochemical properties, and cooking and sensory characteristics of long-grain rice. Four long-grain rice cultivars (purelines: Cheniere and V3501, and hybrids: XP760 and XL753) were cultivated at Harrisburg, AR and Alvin, TX, and harvested at three HMC. Rough rice lots were conditioned and a portion was fractionated according to thickness into thin (<1.9 mm) and thick (≥1.9 mm) fractions. Unfractioned rice and thick kernels were used for further comparison. Overall, rice samples cultivated in TX showed higher amount of broken kernels, chalkiness as well as lower amylose contents compared to those cultivated in AR regardless of the cultivar, possibly due to the greater nighttime air temperatures reported in Alvin, TX. Additionally, textural characteristics and flavor attributes were affected by the cultivating location. Increases in broken kernels, lipid content, and protein content were observed with increasing of HMC. However, cooking qualities were mostly unaffected by HMC. Finally, the addition of thickness fractionation in the process stream showed to improve rice physical quality. However, fractioned rice showed longer cooking duration and a greater width kernel expansion than did unfractioned rice. This study demonstrated that cultivating location and HMC affect rice final attributes and that thickness fractionation may have impacts on cooking and textural characteristics of long-grain rice. Acknowledgements I would like to thank my advisor, Dr. Han-Seok Seo, whose guidance and constant support throughout this journey has provided me a solid foundation for my future professional steps and also life. To my committee members, Dr. Terry Siebenmorgen (Professor, Department of Food Science), Dr. Jean-François Meullenet (Professor and Head, Department of Food Science) and Dr. Paul Counce (Professor, Department of Crop, Soil and Environmental Sciences) for their orientation, monitoring and invaluable inputs in this project. In addition, to all those people that with a small or big contribution helped immensely in the realization of this work, especially all my Sensory Service Center lab mates: Dr. Won Seok Choi (Visiting Professor), Ms. Tonya Tokar (Lab Manager), Ms. Peggy Pang (Lab Technician), Ms. Tina McMaster (Lab Technician), Mr. Matt Chapko (Master student), Ms. Ragita Pramudya (Master student), and Ms. Shilpa Samant (PhD student). Lastly but not least to my parents and sister, Alfredo Jarma, Sulay Arroyo and Betty Jarma, for their continuous support and words of encouragement in the good and not so good moments. Table of Contents Chapter 1. Introduction ································································ 1 Literature Cited ································································ 6 Chapter 2. Literature Review 8 1.1 History ··························································· 9 1.2 Nutritional importance of rice ··············································· 10 1.3 Rice Production and consumption ··············································· 11 1.4 Rice grain morphology ······························································ 12 1.5 Classification of rice grain ···························································· 12 1.6 Pure line and hybrid rice varieties ··················································· 13 2.0 Rice quality ······································································ 15 2.1 Rice physical qualities ························································ 15 2.2 Cooking quality of rice ························································ 21 2.3 Physicochemical properties of rice ·················································· 21 3.0 Sensory aspects of rice ······························································· 24 3.1 Sensory aspects of raw rice ······················································· 24 3.2 Sensory aspects of cooked rice ···················································· 26 Literature cited ················································································ 30 Chapter 3. Evaluation of thickness fractionation as a process to potentially impact cooking qualities and sensory characteristics of long-grain rice (Oryza sativa L.) Abstract ············································································ 38 1. Introduction ······································································ 39 2. Materials and Methods ································································ 41 2.1 Rice Samples Conditioning ······················································ 41 2.2 Thickness fractionation of rough rice and milling properties ··········· 42 2.3 Physical Properties ································································ 43 2.4 Chemical Composition ····························································· 44 2.5 Cooking Qualities ································································ 45 2.6 Descriptive Sensory Analysis ·············································· 46 2.7 Texture Profile Analysis ·························································· 47 2.8 Statistical Analysis ································································ 47 3. Results and Discussion ·························································· 48 3.1 Effect of thickness grading on milling yields and physical 48 characteristics··············································································· 3.2 Effects of thickness grading on chemical properties ···················· 50 3.3 Effects of thickness grading on cooking qualities ························· 53 3.4 Descriptive sensory analysis and texture profile analysis ··················· 54 4. Conclusions ········································································ 55 Literature Cited ············································································· 56 Chapter 4. Effects of Harvest Moisture Content on physicochemical properties and cooking qualities of long-grain rice (Oryza sativa L.) Abstract ································································ 74 1. Introduction ································································ 75 2. Materials and Methods ································································ 76 2.1 Rice samples conditioning and milling properties ···························· 76 2.2 Physical Properties ································································ 77 2.3 Chemical Composition ····························································· 77 2.4 Cooking Qualities ································································ 78 2.5 Statistical Analysis ································································ 78 3. Results and Discussion ································································ 79 3.1 Effect of HMC on physical properties ····································· 79 3.2 Effect of HMC on chemical properties ····································· 81 3.3 Effect of HMC on cooking qualities ····································· 83 4. Conclusions ································································ 84 Literature cited ·················································································· 85 Chapter 5. Effects of cultivating location on physicochemical properties and cooking qualities of long-grain rice (Oryza sativa L.) Abstract ····················································································