Monitoring salting kinetics of pork loin using magnetic resonance imaging (MRI) and time-domain nuclear magnetic resonance (TD-NMR)

Magnetic resonance imaging (MRI) and time-domain nuclear magnetic resonance (TD-NMR) have been used as tools to monitor the salting process in pork loin. For this purpose, the longitudinal (T₁) and transverse (T₂) relaxation times, as well as the apparent diffusion coefficient (ADC), have been employed. To observe the changes occurring in meat pieces during the salting process and to obtain prediction models of the salt (NaCl) and water contents, the potential of each of these parameters has been evaluated. Surface models have been obtained that allow the observation of variations in T₁, T₂, and ADC MRI values related to salt diffusion and water loss during the salting process. Additionally, simple regression models have been established to determine the NaCl and water contents at any time during the process based on T₁ and T₂ values MRI values. On the other hand, to determine the NaCl content of the meat from the TD-NMR study, similar regression models were obtained with the mono-exponential analysis of T₁ and T₂ values. Additionally, the multi-exponential analysis of both T₁ and T₂ has provided insight into the effect of salt intake on the proton populations inside the meat. Thus, it is concluded that MRI and TD-NMR are highly suitable non-destructive techniques for the salt content determination and the monitoring of the salting process in the meat industry.