Evaluation of meat quality in commercial pigs in New Zealand : a thesis submitted in partial fulfilment of the requirements for the degree of Master in Meat Technology, Department of Process and Environmental Technology, Massey University
Evaluation was undertaken of 144 carcasses at two abattoirs in the Manawatu region (New Zealand) to study pork quality characteristics. Surveys were made of farmers, transporters and abattoirs on how they handle the pigs before slaughter. Measurements were made of pH
, colour (visual and Hunter LAB), water holding capacity (WHC) by filter paper press, drip loss and protein solubility of the Semitendinosus and Longissimus dorsi muscles. The pH
was measured at 45 minutes. After 24 hours storage in the chiller, the pH
and WHC were measured and after 30 minutes bloom, the colour measurements (Hunter L A B) and visual colour scores (0 = DFD, 1 = MDFD, 2 = normal, 3 = MPSE, 4 = PSE) were made. The protein solubility was measured within 48 hours postmortem and the drip loss was measured after 48 hours. The carcasses were subjectively classified as DFD (dark, firm, dry), MDFD (mild DFD), normal, MPSE (mild PSE) and PSE (pale, soft, exudative). Sex, breed, age, transport time, distance, last feeding time, weather condition, bruises and laceration/scratches, and stunning time were also recorded. The total incidence of PSEo was 41.98% in the ST and 72.41% in the LD, and the DFDo incidence was 10.65% in the LD and 36.05% in the ST. Almost all the meat quality traits were highly correlated (r = 0.35 to 0.92) and highly significant (p < 0.001) with each other in both muscles used. pH (pH
) was the most dependable technique used in this study. There is no obvious relationship between occurrence of pork quality problem in the pigs and the lairage period or transport distance. However, sex had low but significant correlations with pH
suggesting a possible advantage in treating sexes differently after they leave the farm.