Raman spectroscopy for monitoring protein structure in muscle food systems.

Raman spectroscopy offers structural information about complex solid systems such as muscle food proteins. This spectroscopic technique is a powerful and a non-invasive method for the study of protein changes in secondary structure, mainly quantified, analysing the amide I (1650-1680 cm(- 1)) and amide III (1200-1300 cm(- 1)) regions and C-C stretching band (940 cm(- 1)), as well as modifications in protein local environments (tryptophan residues, tyrosil doublet, aliphatic aminoacids bands) of muscle food systems. Raman spectroscopy has been used to determine structural changes in isolated myofibrillar and connective tissue proteins by the addition of different compounds and by the effect of the conservation process such as freezing and frozen storage. It has been also shown that Raman spectroscopy is particularly useful for monitoring in situ protein structural changes in muscle food during frozen storage. Besides, the possibilities of using protein structural changes of intact muscle to predict the protein functional properties and the sensory attributes of muscle foods have been also investigated. In addition, the application of Raman spectroscopy to study changes in the protein structure during the elaboration of muscle food products has been demonstrated.