1H-NMR Relaxometry and Imaging to Assess Fat Content on Intact Pork Loins

In fresh pork loin, the information concerning fat content is very important, both from the consumer as well as from the nutritional point of view. Knowing the fat content allows industry to classify the fresh loins accordingly. Fat content in loins is a factor related to moisture variability; therefore on-line, non-destructive technologies that could be used in an industrial environment to predict fat-to-moisture ratio are of special interest for companies from the pork processing sector. The time-domain nuclear magnetic resonance (1H TD-NMR), and in particular Relaxometry and Imaging (MRI), has been introduced as a promising alternative to traditional food characterization method due to its rapidity, simplicity, and potential for on-line non-destructive measurements. In this paper, the authors introduce original and innovative procedures using NMR Relaxometry and 1H nuclei imaging which can be employed to estimate the fat content in intact pork loins by exploiting the difference between fat and water longitudinal relaxation time (T1) distributions. They demonstrate how analysis of the quasi-continuous distributions of T1 in fresh intact loins allowed them to obtain a significant relationship between F/W ratios determined from Relaxometry and chemical analysis. This chapter also explains how both NMR Relaxometry and Imaging can estimate the fat-to-moisture ratios in loins in a non-destructive way.