Physicochemical characteristics of three muscles from free-range reared Iberian pigs slaughtered at 90 kg live weight.

Three muscles from free-range reared pigs with different metabolic pattern were studied. m. Masseter (M), m. Longissimus dorsi (LD) and m. Serratus ventralis (SV) the first having an oxidative metabolism and the other two an intermediate and glycolytic metabolism. m. Masseter contained the highest content of myoglobin (M: 6.65 mg/g, LD: 3.00 mg/g and SV: 3.64 mg/g; P<0.001) and exhibited the highest CIE a* (M:17.10, LD: 14.83, SV:15.34, P<0.001) and C* (M: 17.95, LD: 15.61, SV: 15.54, P<0.001) values. m. L. dorsi and S. ventralis contained a higher intramuscular fat content than m. Masseter (M: 2.26 g/100 g muscle, LD: 4.79 g/100 g muscle, SV: 3.52 g/100 g muscle, P=0.001) and lower amounts of phospholipids (M: 0.33 g/g imf, LD: 0.12 g/g imf, SV: 0.19 g/g imf; P<0.001). Fatty acid profiles from total intramuscular fat and lipid fractions, neutral lipids and polar lipids, significantly differed among muscles, there being a higher content of unsaturated fats (especially in the C18:2 and C20:4 percentages) in the m. Masseter than in the other two muscles analysed. Comparatively, muscles from 90 kg live weight Iberian pigs contained more fat and heme pigments and were redder than those from the commercial pig crosses usually produced.