Water transfer analysis in pork meat supported by NMR imaging.

NMR proton density imaging was used to study isothermal and unidirectional drying of pork semi membranosus muscle samples at temperatures of 12, 16 and 20 °C. An independent calibration of the transversal relaxation time T(2) as a function of the moisture content was carried out to convert the signal amplitude into moisture content. Due to spatial heterogeneity in drying, 2D images were needed to assess the evolution of 1D moisture profiles. The relationship between the effective water diffusivity (D) was calculated in function of water content (X) using the Boltzman transformation which needs no a priori on the relationship D=f(X); the effect of lipid content, temperature and fibre direction on this relationship were also studied. In all cases a decrease in water content brought about a decrease in D. A slight increase in lipid content led to a dramatic decrease in D. The fibre direction relative to water movement had a negligible effect. No significative differences in D between the three temperatures were observed, due to variability in the chemical composition of the samples.

[1]  W. D. Hoff,et al.  Unsaturated water flow within porous materials observed by NMR imaging , 1979, Nature.

[2]  KINETICS OF PEPPERONI DRYING , 1977 .

[3]  C. Skjöldebrand,et al.  Water transport in meat during reheating , 1996 .

[4]  Catherine Bonazzi,et al.  MOISTURE DIFFUSION IN GELATIN SLABS BY MODELING DRYING KINETICS , 1997 .

[5]  J. Comaposada,et al.  Meat pH and meat fibre direction effects on moisture diffusivity in salted ham muscles dried at 5 °C. , 2002, Meat science.

[6]  Moisture diffusivity in pasta during drying , 1986 .

[7]  N. Scheerlinck,et al.  Parameter estimation for moisture transport in apples with the aid of NMR imaging , 1998 .

[8]  J. Litchfield,et al.  Nondestructive measurement of transient moisture profiles in ear corn during drying using NMR imaging. , 1990 .

[9]  Arthur R Schmidt,et al.  NONDESTRUCTIVE MEASUREMENT of TRANSIENT MOISTURE PROFILES and the MOISTURE DIFFUSION COEFFICIENT IN A POTATO DURING DRYING and ABSORPTION BY NMR IMAGING , 1991 .

[10]  K. M. Wright,et al.  Fast radial NMR microimaging studies of pasta drying , 1997 .

[11]  W. Horwitz.  Official Methods of Analysis , 1980 .

[12]  J. Renou,et al.  Water Dynamics in Gelatine. Relaxation and Diffusion Analysis , 1999 .

[13]  B. P. Hills,et al.  MAGNETIC RESONANCE IMAGING STUDIES of the FREEZE‐DRYING KINETICS of POTATO , 1994 .

[14]  F. Babonneau,et al.  Radial NMR microimaging studies of the rehydration of extruded pasta , 1996 .

[15]  J. Comaposada,et al.  NaCl content and temperature effects on moisture diffusivity in the Gluteus medius muscle of pork ham. , 2003, Meat science.

[16]  農業技術研究所.  Official methods of analysis of fertilizers , 1982 .

[17]  M. Maeda,et al.  The change of moisture distribution in a rice grain during boiling as observed by NMR imaging , 1997 .

[18]  J. Litchfield,et al.  Simultaneous and nondestructive measurement of transient moisture profiles and structural changes in corn kernels during steeping using microscopic nuclear magnetic resonance imaging , 1992 .

[19]  W. Derbyshire,et al.  Physico-Chemical Studies of Water in Meat , 1975 .