THE EFFECTS OF TEMPERATURE AND MUSCLE COMPOSITION ON THE THERMAL CONDUCTIVITY OF FROZEN MEATS

Efficacy of genetic parameter estimation of pork loin quality of crossbred commercial pigs using technological quality measurements of frozen and unfrozen product

Meat quality characteristics have been measured on fresh and previously frozen meat as part of genetic studies, but freezing of meat may alter its quality characteristics and, therefore, the relationships between genetic components and meat quality measurements. Pork color, pH, and drip loss measurements performed on longissimus dorsi from the carcasses of 2027 crossbred commercial pigs when either fresh or thawed after frozen storage were used to estimate genetic parameters using a bivariate animal model in ASReml. Meat quality traits measured before and after freezing and thawing were significantly (P < 0.0001) different from each other and intramuscular crude fat content exerted a large effect on the magnitude of change in L* (lightness) and b* (yellowness). Meat quality measurements of fresh pork were moderately to highly heritable except for b* and pH, with heritability estimates for L*, pH, and drip loss greater when measured on fresh rather than frozen-thawed samples. Considering heritability and genetic correlation results, we concluded that whilst either fresh or frozen-thawed pork samples can be used for fresh pork L*, a* (redness), and b* measurements, pH, and possibly drip loss should be measured in fresh pork samples rather than in those that have been frozen-thawed during genetic selection for fresh pork quality.