Determination of fat content in meat by pulsed nuclear magnetic resonance (p-nmr) technique

Abstract

This paper reports on the results obtained with the pulsed nuclear magnetic resonance (P-NMR) technique applied for determining fat content in fresh meat. The interfering moisture content of meat was removed by microwave drying and the dried residue was quantitatively transferred into the P-NMR tubes. The total analysis time was about 50 min. Experiments were performed with rendered pure pork, beef and goose fats, sunflower oil and with lean pork - fat and lean beef - tallow mixtures (batters). The regression (prediction) equations (intensity of P-NMR signal vs. fat content determined with the Soxhlet reference method) of the sunflower oil and fat samples did not differ appreciably. Consequently, contrary to the results obtained with the CW-NMR technique, the variability of the fatty acid composition of the examined fats and oil had no substantial effect on the regression (prediction) equations in this case. On the other hand, there was a considerable difference between the regression lines of the lean pork-fat and lean beef-tallow mixtures. Therefore, due to the interfering effect of the non-fat dry matter and the type of meat on the intensity of P-NMR signal, this technique can only have a restricted practical application in the in-line process control of fat content of meats.