@conference {41169,
	title = {Involvement of calpains in postmortem tenderisation: A review of recent research},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {99-102},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Tenderness is an important determinant of meat quality. Inconsistency and variability in tenderness have been identified as major problems for the meat industry (Morgan et al., 1991). It is well documented that tenderness improves during postmortem storage of meat but the mechanisms involved remain controversial. The general consensus is that proteolysis of structural muscle proteins causes tenderisation but alternative theories suggest that changes in the actin-myosin interaction (Goll et al., 1997) or a non-enzymatic effect of calcium on muscle proteins (Takahasi, 1999) or a rise in ionic strength (Ouali, 1990) may be involved. However, discussion of these theories is not within the scope of this review. With regard to postmortem proteolysis, the calpain system is thought to play a major role. Calpains are calcium-activated proteases with an optimum activity at neutral pH. In skeletal muscle, the calpain system consists three proteases, m-calpain, m-calpain and skeletal muscle-specific calpain, p94, and an inhibitor of m- and m-calpain, calpastatin. The involvement of calpains in postmortem tenderisation has been the subject of several reviews (Goll et al., 1991; Koohmaraie, 1988, 1992a, 1994, 1996; Ouali, 1990). Since these reviews, new information has become available which has provided answers to some of the questions on the role of calpains in postmortem tenderisation. The purpose of this review is to discuss some of these issues in the context of recent results. For further information on postmortem proteolysis and meat tenderness, or characteristics of the calpain system, the reader is referred to a number of excellent reviews (Penny, 1980; Greaser, 1986; Croall and DeMartino, 1991; Ouali, 1992; Sorimachi et al., 1994; Ono et al., 1998). },
	issn = {1176-5283},
	author = {Geesink GH and Ilian MA and Morton JD and Bickerstaffe R}
}
@conference {41137,
	title = {Marker-assisted Selection for Meat Quality and the Ovine Calpastatin Gene},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {59},
	year = {1999},
	month = {Jan},
	pages = {266-268},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The calpain-calpastatin system (CCS) comprises a family of calcium-dependent neutral proteases, the calpains, and calpastatin, a specific inhibitor of the calpains that regulates their activity in vivo. The CCS is found in most animal tissues and influences many important processes including muscle development and degeneration, meat tenderisation postmortem, cataract formation and fertility. The calpains have been shown to play the major role in postmortem tenderisation in beef, lamb and pork by degrading specific muscle structural proteins. The level of calpastatin immediately postmortem appears critical in determining the ultimate tenderness of aging muscles. Tenderness has been shown in consumer surveys and tasting panel tests to be the most important characteristic determining the overall eating quality of meat. In using a molecular genetic approach to studying meat quality in sheep we have chosen the ovine calpastatin gene (CAST) as a candidate gene for meat quality. We have described a three allele system of polymorphic variants (CAST a, b and c) in a region of the ovine CAST. Since 1995 we have carried out slaughter trials on small groups of Dorset Down hoggets and Dorset Down x Coopworth lambs to ascertain any association between meat quality traits and the molecular markers in CAST. Sheep with the genotypes of CAST aa, ab and ac were compared. These trials indicate an association of the CAST genotype ac with increased liveweight gain (+12-17\%,p >0.05), increased age-corrected carcass weight (+15-18\%, p>0.05), but also increased longissimus dorsi shear force (+4-12\%, nonsignificant) compared to sheep with the CAST genotype aa. },
	issn = {1176-5283},
	author = {Palmer BR and Morton JD and Roberts N and Ilian MA and Bickerstaffe R}
}
