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Magnetic resonance imaging analysis of longitudinal relaxation times (T1 values), transverse relaxation times (T2 values), magnetization transfer (MT) rates and apparent water diffusion coefficients (D) was used to authenticate the effect of freezing/thawing in longissimus dorsi pig muscle; these NMR parameters were compared with the gravimetric moisture content values obtained independently by oven drying. A significant increase in the MT rate was observed between fresh and frozen/thawed pork prepared from the same animal; however, measurements of other parameters showed little or less significant changes. The significant increase in the MT rate is associated with both the decrease of moisture content in pork after freezing/thawing and with the denaturation of myofibrillar proteins in frozen/thawed pork. On that basis, the present NMR results imply that the duration of the freezing period (from 2 weeks to 2 months at ‐18°C) did not significantly enhance the denaturation of the meat proteins. © 1997 John Wiley & Sons, Ltd.

A Dixon NMR imaging experiment was used to map the spatial distribution of either the water or lipid protons in sunflower oil and water and meat and fat emulsions. A phase correction algorithm was applied to the experimental image data compensate for regional inhomogeneities of the magnetic field and allowed the water and lipid concentrations from any region in the image to be measured quantitatively.