Application of electron spin resonance (ESR) spectrometry in nutraceutical and food research

Electron spin resonance (ESR) spectroscopy is able to directly measure the chemical species with unpaired electrons and has been widely used in a number of research fields. This review focused on its application in nutraceutical and food research. Current status of ESR in free radical scavenging capacity estimation, food oxidative stability evaluation, Cu(2+) chelating capacity determination were summarized. Also discussed was the potential of ESR spin-label oximetry technique in examination of lipid peroxidation and oxygen diffusion-concentration products in liposomes, oxygen transport and depletion, and membrane structure and dynamic properties. In addition, ESR application in identifying and estimating irradiated foods including meat, fruits, vegetables, spices, cereal grains, and oil seeds was reviewed. Finally, the potential use of ESR technique in investigating microstructure change, phase transition and viscosity related properties during food formulation, processing, and storage was briefly mentioned, along with its potential in determination of radio-stability of food components. This review may provide some fundamental knowledge of ESR and its application in nutraceutical and food research.