FT-NIR spectroscopy of treated blood plasma to predict carcass and meat quality of young female rabbits.

In two replications, involving a total of 32 young females (slaughter-weight 3648 g), half of the rabbits were restricted from solid feeding for 36 hours. The applied fasting treatment resulted in minor global effects (multivariate R²=0.35) in comparison to the replication effects (R²=0.81), which caused remarkable differences in some conventional variables of meat quality. The blood samples were centrifuged and the plasma (1 ml) was submitted to a rapid reaction with ethanol (ETA: 0.5 ml) or to a freeze-drying (FD) process before being examined by FT-NIR spectroscopy (1000-2500 nm). The spectra were correlated and cross-validated to fixed experimental effects: fasting and replication, as binary data (1, 2). Some biological and quality traits of the meat and carcass were also fitted by ISI-2 software chemometrics. In short, 1-VR cross-validated values, which resulted after a double passage for outlier elimination using a liberal t-level of 2, are reported. Replication effects were clearly present in the NIR spectra and appeared to be higher for the FD samples (0.87) than for the ETA ones (0.59). Intramuscular fat in Obliquus abdominis and hindleg muscles were more represented in the ETA (0.55; 0.63 respectively) than in the FD spectra (0.26; 0.26), as were the interscapular fat percentage (0.44; 0), the water content of Longissimus thoracis et lumborum (0.41; 0) and of Obliquus abdominis muscles (0.52; 0.32), and the meat-to-bone ratio (0.39; 0.25), but the liver percentage (0.25; 0.40) was not. The colour and rheological meat quality traits did not generally appear to be correlated to the FT-NIR spectra. The first conclusion that was made was that the freeze-drying of plasma samples does not improve the method, which can function rapidly after a very simple alcohol reaction. The confirmation of several significant relationships with the FT-NIR spectra of plasma will encourage this kind of study, starting from live animals.