SOLUBILITY OF BEEF AND CHICKEN MYOFIBRILLAR PROTEINS IN LOW IONIC-STRENGTH MEDIA

Myofibrillar proteins were extracted and solubilized at ionic strengths not exceeding 30 mM. This was accomplished by treating homogenized muscle with a succession of washes in dilute salt solution (25 mM NaCl, 2.5 mM histidine, pH 7.4). It was possible to achieve up to 36% solubility of total protein from various beef and chicken muscles. These values compared favorably with published results for extractions using high salt concentrations (0.6 M). Electrophoretic separation of extracts demonstrated that all myofibrillar species were present. A strong positive relationship (r = 0.95) was found between protein yield in the initial homogenate and literature values for percentage of white (type IIb) fibers in the muscle. Swelling of muscle proteins was associated with a higher level of protein solubilization.