1st Edition

Water in Foods and Biological Materials

By R. Roger Ruan, Paul L. Chen Copyright 1997
    312 Pages
    by CRC Press

    This book is the first book on nuclear magnetic resonance study of water in food and biological materials. The authors present the methodology, research, and development results of qualitative and quantitative analysis of water in foods and biological materials using NMR and MRI.
    This book provides the latest NMR and MRI techniques for those researchers who have an interest in relationships between water and:
    * chemical reactivity
    * microbial activity
    * physiochemical properties and changes
    * structural properties and changes in foods and biological materials

    In addition, the authors emphasize experimental techniques and data interpretation skills for the study of mobility of water and its role in processing and storage of foods and biological materials.
    Authors Ruan and Chen explain how the "state of water" concept will greatly add to the reader's understanding of the role of water in chemical, physical and microbial changes occurring in foods and biological materials.
    Understanding the relationships between water and chemical reactivity, microbial activity, and physiochemical and structural properties and changes in foods is an important key to effective food R&D, as well as quality control in processing and storage.
    This book provides advanced information on these relationships using the tools of NMR and MRI. Emphasis is placed on experimental techniques and data interpretation skills for the study of mobility of water and its role in processing and storage of foods. Many new techniques and applications are examined. More than 140 schematics, images and graphs illustrate NMR/MRI principles, techniques, applications and results.

    Each chapter ends with a section of references.
    Nuclear Magnetic Resonance Techniques
    Basic Principles of NMR: - Vector Diagrams of Magnetization - Relaxation Processes - Measurement of Relaxation Times - NMR Spectrometer Hardware - Magnetic Resonance Imaging (MRI): - Conventional Microscopy versus Magnetic Resonance Imaging - Basic Principle of MRI - Imaging Relaxation Time, Chemical Shift, and Flow Velocity - MRI Hardware - Incorporation of Experimental Devices into MRI Instrument

    Aspects of Water in Food and Biological Systems
    Introduction - Chemical Composition and Structure of Water - Bonding in Water - Mobility of Water in Biopolymers - Research Interests in Water in Food and Biological Materials: - Water Content versus Water Mobility - Migration of Water - Glass Transition - Chemical and Biochemical Reactions - Physiological States of Biological Materials

    Rapid Determination of Moisture in Food and Biological Materials
    Introduction - Basic Principles - Techniques: - Liquid-Solid Ratio Method - Proportional Method - Model Fitting Method - Spin-Echo Method - High Resolution Method - Composite Pulse Sequence Method

    Migration of Water
    Introduction - Moisture Distribution in Low and Intermediate Moisture Foods and Biological Materials - Mapping of Moisture and Fat Separately in Foods: - Chemical Shift Selective (CHESS) Presaturation - Frequency-Selective: - Excitation - Dixons Method - Relaxation Based Suppression Techniques - Hybrid Techniques - Real-Time Monitoring of Food Processes: - Diffusion of Water in Model Systems - Barley Steeping - Soaking of Navybeans - Drying of Soybeans - Cheese Cooling - Freeze-Thaw Cycles during Freezing Storage - Use of Pulsed Field Gradient (PFG) NMR to Study Diffusional Characteristics - MRI Experiment and Computer Simulation for Modeling of Simultaneous Heat and Moisture Transfer in Cheese: - Mathematical Model for Heat and Moisture Transfer - Numerical Scheme - Results

    Mobility of Water in Food and Biological Systems
    Water Activity and Mobility of Water: - Water Activity - Mobility of Water Measured by NMR - Physiochemical Principles of Nuclear Reaction - Methodology for Determination of States of Water: - Mono-Exponential Decay - Multi-Exponential Decay and Continuous Distribution of Relaxation Time - Self-Diffusion Coefficient Approach - States of Water and Staling of Starch-Based Products: - Sweet Rolls and Starch Gel: Experiments, Results and Discussion - Bread: Experiments, Results and Discussion - Wild Rice: Experiments, Results and Discussion - Flour Dough: Water in Dough, Curve-Fitting Model, Continuous Distribution Model, Dough Mixing - Chemical and Microbiological Activities

    Water and Physiology of Plant Materials
    Introduction - Development Stage - Quality of Fruits and Vegetables - Stress Tolerance and NMR Property of Water in Plant

    NMR and MRI Studies of Glass Transition in Foods and Biological Materials
    Introduction - Molecular and Segmental (Brownian) Motions in Polymers - NMR Relaxation and Brownian Motions - Experimental Setup for Study of Glass Transition in Biopolymers Using Pulsed NMR - Advantages of NMR Method over Conventional Methods - MRI Mapping of Glass Transition Temperature



    R. Roger Ruan; Paul L. Chen