Abstract: Eighty-four Laiwu Black (LW) (weight of 30-90kg, n=6) and Lulai Black (LL) pigs (weight of 40-100kg, n=6) were used to study the development changes of intramuscular collagen and their relationship to meat quality. The results showed as follows: Weight of LW had significant effects on muscle total collagen (TC), insoluble collagen (IC) (P<0.01), collagen solubility (CS) (P<0.05), marbling score (MS) (P<0.01) and shear force (SF) (P<0.05). Weight of LL had significant effects on muscle TC, soluble collagen (SC) (P<0.05), IC, CS, MS (P<0.01), cooking percentage (CP) and Napole yield (NY) (P<0.05). These two breeds, on the whole, had similar development changes of intramuscular collagen. Increased weight of pigs was associated with an increase in muscle TC, IC and water binding capacity (WBC), but tended to be related with a decrease in muscle SC, CS and tenderness. Compared with LL, LW were generally higher in muscle TC, CS, MS and WBC, but lower in SF. It was proved that as the whole muscle, bundles of fibers and individual fibers are surrounded by a delicate collagenous network like sheaths, the increase of quantity of collagen and its cross-links was found to be highly correlated to muscle WBC improvement and toughness (P<0.01), whereas, the increase of amounts of marbling was strongly correlated to WBC improvement (P<0.05) but not to toughness.

Key words: Muscl, Collagen, Meat quality, Development, Laiwu pig