Low-Field Nuclear Magnetic Resonance of Proton (1H LF NMR) Relaxometry for Monitoring the Time and Temperature History of Frozen Hake (Merluccius merluccius L.) Muscle

Abstract

The objective of the work was to investigate the potential of low-field nuclear magnetic resonance of protons (1H LF NMR) relaxometry to produce indicators useful in the estimation of the quality and shelf life of frozen hake (Merluccius merluccius L.) muscle as affected by storage temperature and time. 1H low-field NMR T 2 transverse relaxation measurements were performed from fillets of a total of 145 hakes that had been stored at −10, −20, −30, or −80 °C for up to 150 weeks. The principal component (PC) scores from the 1H LF NMR distribution of T 2 relaxation times were adjusted to zero-order kinetics and the reaction rates followed an Arrhenius-type pattern. Kinetic modeling using the PC scores of the 12–400-ms range resulted in the best model corresponding to both T 21 and T 22 regions. The temperature dependency of the rate of reactions, measured by B values, was similar to that previously found for shear resistance and for the hydrolysis of phospholipids, well-known markers related to the sensory quality in this species. Thus, our results suggest that this methodology has a great potential to evaluate the frozen storage time and temperature in hake as well as to provide an indication of the expected quality of the fillet.