Comparison of meat quality between breeds, sex and site of longissimus thoracis muscle in pigs

摘要

The effect of breed, sex and site of longissimus thoracis muscle on meat quality and the correlations between meat quality traits were investigated. Three pure breeds (Landrace : L, Large white : W, Duroc : D) and two crossbreds (LD, LWD) were compared in this experiment. Two or three barrows or gilts, respectively from each pure breed and crossbreed were used (total of 28 pigs). At 105 kg of body weight, the pigs were slaughtered. Two sites of the longissimus thoracis muscle (front site : 6th and7th dorsal vertebrae, rear site : 2 dorsal vertebrae from the last vertebra) of each pig were sampled after 24 hours after slaughter. Cooking loss, meat color, physical traits (Tenderness, Pliability and Toughness) and intramuscular fat content at both sites of the longissimus thoracis muscle were measured. Further drip loss and pH of the rear site of the longissimus thoracis muscle were measured. The muscle fiber diameter, primary muscle bundle area and muscle fiber number at the 11th-12th dorsal vertebrae also were measured. Significant breed effects on the meat quality traits were detected in all the traits except for b~* value, muscle fiber diameter and muscle fiber number. Duroc breed had more intramuscular fat, softer meat, dark meat color, lessdrip loss and cooking loss than other purebred and crossbred. There were significant sex effects in L~*, b~* and a~* value, moisture and intramuscular fat and Pliability. There were significant site effect on all the meat quality traits except for cooking loss and moisture content. The L~* value significantly correlated with cooking loss for the front site (r=0.465) and the rear site (r=0.400). Further, for the rear site of the longissimus thoracis muscle, the correlation of the L value with drip loss was significant. Although the intramuscular fat content significantly correlated with Tenderness (r=-0.673), Pliability (r=0.546) and Toughness (r=- 0.467) at the front site of the longissimus thoracis muscle, at the rear site of the loin the correlationbetween intramuscular fat and these traits were very low. Tenderness was significantly correlated with muscle bundle area (r=0.508). It is suggested that the muscle bundle area is a primary factor on Tenderness.