Objective measurements of pork quality: evaluation of various techniques

Research has been undertaken in which various methods for meat quality evaluation were compared. The measures used were pH (by homogenization and by combined electrode), light scattering conductivity, dielectric loss factor and colour. A very low incidence of PSE (Pale, Soft, Exudative) and DFD (Dark, Firm, Dry) cases was observed and the correlation between pH, as measured by homogenization and by combined electrode, did not appear to be completely satisfactory. Dielectric loss factor, as measured by the MS tester, seems to be specifically suited for PSE diagnosis. On the other hand, higher values of light scattering and conductivity measured at 24 h post mortem, are found to be linked to the rate of pH fall, even outside the range for PSE. Colour measurements, especially of the parameters L*, a* and hue angle, have given interesting information. In fact, meat could be classified by colour intensity (a*, psychometric chroma), by type of colour (hue angle) and by exudative phenomena (L*). No marked effects of rearing techniques have been observed, whereas the genetic background appears to influence some colour parameters. Slaughter conditions, on the other hand, could affect markedly all the meat quality parameters measured in this research.