Applications of NMR to Food to Food Science

Abstract

This chapter provides an insight on applications of nuclear magnetic resonance (NMR) to food science. It also considers two new NMR methods, which prove to be of general usefulness. These are magic angle spinning for improved resolution in proton spectra, and the use of Z spectroscopy in which polarization is transferred from biopolymer protons to water protons to allow mapping of the biopolymer lineshape. A list of reviews on the applications of NMR in food science is tabulated. NMR water relaxation measurements can provide a powerful probe of the amount and mobility of water in foods. The growing activity in the investigation of plant cell walls is by NMR. Cell walls can be regarded as a heterogeneous polymer matrix, and one of the classical ways to apply NMR to such a system is to look at proton relaxation processes. There have also been developments in methodology in the exploitation of polarization transfer methods by the use of Z spectroscopy. A continuing major application of NMR in food science is the use of isotopic and other methods for the authentication of foods and the detection of adulteration. The most important applications of NMR are the determination of oil and water contents and the solids contents of fats. Some other applications of NMR are in tea, coffee, wine, lipids, fruits, vegetables, milk, and meat.