title: Explaining the variation in lamb longissimus shear force across and within ageing periods using protein degradation, sarcomere length and collagen characteristics.
abstract: Meat tenderness is known to be affected by sarcomere length (SL), proteolysis and collagen content (CC). Sixty lambs were slaughtered and the Longissimus muscle was sampled. Samples for shear force (SF), SL, proteolysis indicators (desmin degradation, particle size: PS) and CC were taken after the allotted ageing periods (1, 7, and 14 days). PS explained a large part of the variation in shear force (approximately 34%) when modelled across ageing periods. Other factors (CC, SL) combined with proteolysis indicators (PS, desmin degradation) explained just under 40% of the variation in shear force. Within ageing periods SL explained a small, but significant, part of the variation in shear force after 14 days of ageing (8%) and at day 1 of ageing desmin degradation explained 17% of the variation in shear force. Methods to improve the tenderness of lamb longissimus muscle should focus on increasing the extent of post-mortem proteolysis, when processing conditions are sufficient to prevent muscle fibre shortening.
authors.affiliation: Cooperative Research Centre for Sheep Industry Innovation, Armidale, New South Wales, Australia; University of New England, Armidale, New South Wales, Australia. Electronic address: cstarkey@myune.edu.au.
authors.forename: Colin P
authors.initials: CP
authors.lastname: Starkey
authors.affiliation: University of New England, Armidale, New South Wales, Australia.
authors.forename: Geert H
authors.initials: GH
authors.lastname: Geesink
authors.affiliation: NSW Department of Primary Industries, Beef Industry Centre, UNE, Armidale, New South Wales, Australia.
authors.forename: V Hutton
authors.initials: VH
authors.lastname: Oddy
authors.affiliation: NSW Department of Primary Industries, Centre for Red Meat and Sheep Development, Cowra, New South Wales, Australia.
authors.forename: David L
authors.initials: DL
authors.lastname: Hopkins
mesh_terms: D000003:Abattoirs; D000818:Animals; D055598:Chemical Phenomena; D003094:Collagen / Q000737:chemistry / Q000378:metabolism*; D003893:Desmin / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D063427:Food Quality; D061353:Food Storage; D006863:Hydrogen-Ion Concentration; D008297:Male; D008460:Meat / Q000032:analysis*; D055595:Mechanical Phenomena; D018482:Muscle, Skeletal / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D009517:New South Wales; D009919:Orchiectomy / Q000662:veterinary; D010316:Particle Size; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism; D059748:Proteolysis; D012034:Refrigeration; D012518:Sarcomeres / Q000737:chemistry / Q000378:metabolism*; D033081:Shear Strength; D034561:Sheep, Domestic
chemical_list: D003893:Desmin; D010446:Peptide Fragments; D003094:Collagen
keywords: Collagen; Lamb; Proteolysis; Sarcomere length; Tenderness