Evaluation of inherent variation in porcine M. thoracis et lumborum and M. semimembranosus

Abstract

Variation in quality traits may occur between the different muscles within a carcass and also within a muscle. This study examined inter-and intramuscular variation and the resulting effect on measurements (pH, conductivity and colour) taken within 24 h post mortem. The effect of shackling on these quality prediction measurements was also determined. Finally the inherent variability of quality attributes within porcine M. longissimus thoracis et lumborum (LTL) was examined at 4 days post mortem. Significant intermuscular variation was detected at 24 h post mortem, with higher pH and conductivity values recorded in the M. semimembranosus (SM) than in the LTL. pH and conductivity measurements in both muscle types were correlated (r = 0.46-0.88, P < 0.05) at 45 min and 3 h post mortem. CIE L * and a * values, % reflectance and Japanese pork colour scores were significantly (P < 0.001) different in the neck region (M. biventer cervicis and M. splenius) than on the surface of the SM and M. gluteus medius. An intramuscular effect was not observed in either SM or LTL muscles. Shackling did not introduce a significant variation between sides for pH, conductivity and colour measurements taken up to 24 h post mortem. At 4 days post mortem it was determined that the water-holding capacity, tenderness (Warner-Bratzler Shear force) and composition of the LTL are not dependent on sampling location within the muscle. These results suggest that meat quality measurements are uniform throughout the LTL (loin) and that a significant relationship exists between the LTL and SM muscles.

Comparative proteomic profiling of 2 muscles from 5 different pure pig breeds using surface-enhanced laser desorption/ionization time-of-flight proteomics technology1

“…To our knowledge, there are no studies that report protein expression patterns of the BL breed between muscles and compare them with other different breeds. However, a likely explanation is that the BL breed can be associated with a greater variation in muscle metabolism and structural proteins, within carcasses (McDonagh et al, 2006). Finally, on the IMAC30 ProteinChip array the 4,046 m/z peak was considered to be a helpful protein for muscle classification within the PI breed.…”