Application of NMR to Resolve Food Structure, Composition and Quality
Pp. 3-61 (59)
Angela Melado-Herreros, María E. Fernández-Valle and Pilar Barreiro
Food is a complex system formed by several chemical compounds and
physical structures at different organization levels. For food analysis and
characterization, it is not only important the study of the chemical composition, which
will define the nutrient content, but also the physical distribution of the different
compartments and structures that will define the physical properties of food products.
Physical properties of food will define the palatability and texture of the food product
and thus, the acceptance by the consumers. When talking about Nuclear Magnetic
Resonance (NMR) spectroscopy we refer to several techniques that study the
interaction of electromagnetic radiation with matter. Nuclear magnetic spectroscopy is
the use of the NMR phenomenon to study physical, chemical and biological properties
of matter, from the microscopic to the macroscopic. NMR spectroscopy is a very
successful and multipurpose technique which is very suitable combined with
chemometrics, for the analysis of food products . In this chapter, we will review
several NMR techniques that are related to both chemical and physical characterization.
Such techniques are 1H High-Resolution Magic Angle Spin (1H HR-MAS), which
provides a high resolution chemical spectrum without component extraction ,
relaxometry, which gives information about the water compartmentation, structure and
integrity , magnetic resonance imaging (MRI) and chemical shift imaging (CSI),
which is an efficient tool for the physiological analysis of fruit and vegetables . The
following chapter will address, first of all, what needs to be measured on food, as well
as several NMR techniques that have been used for the analysis of food products. These techniques are 1H High Resolution Magic Angle Spin (1H HR-MAS), MRI, 1D
and 2D relaxometry, relaxometry mapping and chemical shift imaging. We further
focus on the explanation of multicomponent analysis and finally offer some remarks
about prospects in the field.
Chemical properties, Chemometrics, Food structure, Macrostructure,
Microstructure, Physical properties, Structure, Texture.
LPF-TAGRALIA, Technical University of Madrid. ETSI Agronomos, Avda. Complutense s/n. 28040, Madrid, Spain.