Muscle, sex and carcass weight affected pork collagen characteristics, intramuscular fat content and eating quality

Pork quality is affected by carcass weight, sex and muscle. In this study, castrated male and female pigs from three supply chains with two carcass weight groups (high: 95.0-100.0 kg; low: 75.0-80.0 kg) were slaughtered during an Australian summer (February) and winter (August). Biceps femoris (BF), longissimus thoracis et lumborum (LTL) and triceps brachii (TB) were excised from each carcass at 24-48 h postmortem and kept frozen until analysis. They were used to analyze for pH, collagen content and solubility, intramuscular fat (IMF) and sensory evaluation. Consumers were asked to assess their tenderness, juiciness, liking of flavor, overall liking, quality grading, purchasing intent and check-all-that-apply (CATA). Results showed that TB had the highest pH (5.92 vs 5.77 and 5.67, P < 0.001), collagen (7.31 vs 5.88 and 4.07 mg/g, P < 0.001) and IMF content (2.43 vs 1.18 and 1.08%, P < 0.001), and received the highest scores in sensory tenderness (67.8 vs 44.7 and 47.6, P < 0.001), juiciness (67.3 vs 53.0 and 50.7, P < 0.001), flavour liking (61.0 vs 52.4 and 52.0, P < 0.001) and overall liking (65.5 vs 50.8 and 50.9, P < 0.001) than BF and LTL. BF and LTL did not differ in all sensory attributes. But CATA showed that BF was more fibrous, chewy and porky, while LTL was associated with clean, dry, sour and tasteless. Pork from heavier carcasses was perceived as fattier, more savory and less fibrous. Collagen solubility was positively related to sensory tenderness, while IMF was positively related to juiciness and overall liking. Collagen and IMF influenced pork eating quality.