Post mortem proteome degradation profiles of longissimus muscle in Yorkshire and Duroc

Post mortem enzymatic proteolysis changes tough intact muscle tissue into tender meat. The extend of muscle protein proteolysis greatly determines the quality of the meat: inadequate proteolysis produces tough meat, too much proteolysis is associated with increased drip loss which also reduces tenderness and juiciness of the meat. While information on the proteolysis of several specific proteins is available, knowledge regarding the progress of proteolysis on the entire proteome of muscle tissue is limited. Furthermore, breed-specific differences have received little attention. Therefore, this study we investigated breakdown profiles of the longissimus proteome of Yorkshire and Duroc pigs. Multiple samples of longissimus muscle tissue of five pigs of each breed were collected and drip loss, cooking loss, shear force, as well as proteome profiles, using SELDI-TOF technology, were determined after 1, 2, 3, 7, and 10 days. Drip loss increased with ageing and was slightly higher in Yorkshire than in Duroc longissimus while cooking loss was unchanged during ageing and similar in both breeds. Shear force decreased with ageing time. Shear force decreased more in Yorkshire compared to Duroc, but profiles differed between animals. The number of peptides detected with SELDI-TOF was higher in York than in Duroc. It suggests a relationship between ageing-related levels of proteolysis and meat quality trait