title: Effect of beef ultimate pH and large structural protein changes with aging on meat tenderness.
abstract: This study investigated the effect of ultimate pH (pHu) in beef on the degradation of large structural proteins during refrigerated storage using SDS-PAGE. M. longissimus dorsi from bull carcasses were selected and classified into three groups: low pHu (≤5.79), intermediate pHu (5.80-6.19) and high pHu (≥6.2) muscles. Samples were then stored at -1.5°C for 1, 2, 7, 14, 21 and 28days. Meat tenderness was measured at each aging time. Depending on meat pHu, different protein patterns and degradation rates of structural proteins were found. Rapid changes of large structural proteins took place within 48h post mortem. Besides titin and nebulin, degradation of filamin was clearly revealed. Two more large protein bands corresponding to myosin family members also exhibited fast decline with storage time. It suggested that the fast degradation of these proteins is a key factor in the improvement of meat tenderness.
authors.affiliation: AgResearch Ltd, Ruakura Research Centre, Hamilton, New Zealand. Electronic address: guojie.wu@agresearch.co.nz.
authors.forename: G
authors.initials: G
authors.lastname: Wu
authors.affiliation: AgResearch Ltd, Ruakura Research Centre, Hamilton, New Zealand.
authors.forename: M M
authors.initials: MM
authors.lastname: Farouk
authors.affiliation: AgResearch Ltd, Lincoln Research Centre, Christchurch, New Zealand.
authors.forename: S
authors.initials: S
authors.lastname: Clerens
authors.affiliation: AgResearch Ltd, Ruakura Research Centre, Hamilton, New Zealand.
authors.forename: K
authors.initials: K
authors.lastname: Rosenvold
mesh_terms: D000818:Animals; D002417:Cattle; D004044:Dietary Proteins / Q000378:metabolism*; D005511:Food Handling / Q000379:methods*; D063427:Food Quality; D006863:Hydrogen-Ion Concentration; D008297:Male; D008460:Meat / Q000032:analysis*; D009124:Muscle Proteins / Q000378:metabolism*; D009520:New Zealand
chemical_list: D004044:Dietary Proteins; D009124:Muscle Proteins
keywords: Beef pH(u); Degradation; Refrigerated storage; Structural proteins; Tenderness