Proximate and protein compositions of requiem shark muscle.

Abstract

Proximate and Protein compositions of the ordinary muscle of requiem shark Triakis scyllia were examined. The proximate composition of the dorsal muscle was: moisture 76.0%, crude protein 24.9%, crude fat 2.7%, and crude ash 1.3%, The proein content corrected for urea (5.4mgN/g) and for non-protein nitrogenous compounds (11.2mgN/g) was 21.5% and 17.5%, respectively. The protein compositions of the dorsal and ventral muscle remained unchanged essentially through pre-, in-, and post-rigor stages: In the dorsal part, sarcoplasmic 22.1-25.9% (av. 24.5%), myofibrillar 60.1-66.8% (63.2%), alkail-soluble 4.1-5.5% (4.7%), and stroma fraction 6.5-8.9% (7.6%). In the ventral part, corresponding data were 20.4-26.1% (24.2%), 58.4-67.2% (63.5%), 2.9-9.2% (6.1%), and 3.8-8.2% (6.1%), respectively. The protein composition of each muscle did not show any significant changes after a 2-week frozen storage at -20°C.