Role of Calpains in Postmortem Proteolysis in Chicken Muscle

Abstract

Tenderness is governed by postmortem biochemical processes, particularly proteolysis. In mammals, the calpain system is generally accepted as the main system involved in postmortem proteolysis. In poultry, the 2 calpains (mu and mu/m--a form only found in bird tissue) have greater calcium sensitivity. In this study, we quantified by zymography the changes in postmortem calpain system activity. The mu/m-calpain activity remained steady, whereas the mu-calpain activity had disappeared by 6 h after postmortem, showing an activation by calcium. Changes in the electrophoretic pattern of sarcoplasmic and myofibrillar proteins are observed in the first postmortem hours concomitantly to the decrease in mu-calpain activity. The 30-kDa protein, considered as a good marker of postmortem aging in cattle, appeared from 6 h and then steadily increased. In chicken muscle, the rapid maximum tenderness reached could be explained by a greater activation of the calpain system.

Thin-filament length correlates with fiber type in human skeletal muscle

“…Namely, Tmod is a dynamic cap, and the injury imposed on the muscle tissue by the biopsy excision procedure may lead to calpain-mediated proteolysis of myofibrillar components (15,16,31), including Tmod, followed by Tmod dissociation from the thin-filament pointed ends. This can potentially lead to actin monomer addition and artifactually increased thin-filament lengths.…”

A comparative study of physico-chemical and functional properties, and ultrastructure of ostrich meat and beef during aging

“…The increase in solubility of total proteins during storage could be due to the proteolytic activities resulting in shorter peptides and free amino acids (Azad & Akter, 2005;Montero, GÓ Mez-guille´n, & Borderias, 1996;Zhang, Farouk, Young, Weliczko, & Podmore, 2005). It is generally accepted that proteolysis of the myofibrillar structure is an important factor in protein solubility and meat tenderness and that 90% or more of the observed proteolytic activity during the first 7-10 days of postmortem storage at 2-48C can be attributed to the calpains (Lee, Sante´-Lhoutellier, Vigouroux, Briand, & Briand, 2008;Sazili, Parr, Sensky, Jones, Bardsley, & Buttery, 2005).…”

Influence of ageing time on yield and texture of marinated chicken breast cooked using a continuous process

“…Similar values were reported by Young et al (1999) that had found pH 6.19 after deboning and pH 5.96 to 6.08 for deboning times of 2 to 6 hours. Lee et al (2008) found a decrease in pH from zero to 6 hours, time which the muscle had reached its final pH (rigor mortis). Thielke et al (2005) observed pH decrease during the first 5 hours of aging, 6.83 to 5.91.…”

“…Ageing is an alternative to reduce these problems, consisting in exposing the meat to controlled temperature (0 to 4°C) for a determined period of time (6 to 24 hours) (KOMIYAMA et al, 2009;LIU et al, 2004;LEE et al, 2008). The ageing time before deboning is one of the most important factors for the final texture of the meat (SOUZA et al, 2005).…”