Probing Water Relations in Foods Using Magnetic Resonance Techniques

Water is an essential and pervasive component of life. It is abundant in all three physical states-solid, liquid, and gas. Water serves a sundry of vital functions: as an environmental and body regulator, as a transportation and solvent medium for cellular functions, as a stabilizer of biopolymer conformation, as a reactant, product and solvent for many chemical and biological reactions, as a major constitution of most foods, and countless other functions. The importance of water in foods begins with the hydrological cycle, that is the continuous circulation of water by evaporation from the hydrosphere and its subsequent precipitation back from the atmosphere. This cycle provides the necessary water for the fundamental elements of the world's food supply, crop, and animal production. Water continues to be a vital component throughout the various stages of food production, such as harvest or slaughter, addition of other ingredients, processing, and storage. NMR techniques have been successfully used in a number of disciplines, such as chemistry, polymer science, and food science, to study a variety of phenomena ranging from molecular structure to water dynamics to chemical composition. Based on the principles of NMR, Lauterbur developed an imaging method to map the spatial distribution of select nuclei within an object, which he called NMR zeugmatography.