Estimation of quality in frozen fish by low field NMR

Abstract

This chapter addresses the potential of LF 1H NMR relaxometry to estimate the quality of fish products during freezing and frozen storage. This technique has shown to be, at least for some fish species, sensitive to changes occurring at subzero temperatures and the variation in the relaxation times kept a relationship with documented effects on the morphological and biochemical alterations of fish muscle. Moreover, the dependency of the relaxometry data on the freezing time and temperature has allowed the identification of indicators suitable for the estimation of shelf life, thus contributing to the increasing range of applications of the T 2 decay signals.