Functional Properties of Myofibrillar Proteins from Cold‐Shortened and Thaw‐Rigor Bovine Muscles

Prerigor bovine sternomandibularis muscles were stored at 15, 0 and −29°C to examine cold‐shortening and thaw‐rigor effects on myofibrillar protein extractability and gelation properties of myofibrils and salt‐soluble protein (SSP). Frozen muscle that underwent severe contraction at thawing showed greater protein extractability (35%) than muscles stored at 0 and 15°C (27% extractability). Of the three tempered muscles, thaw‐rigor muscle produced the strongest myofibril gel and cold‐shortened muscle formed the most elastic SSP gel as determined by dynamic shear and penetration measurements. However, thermally induced changes in gel viscoelastic moduli for all protein samples followed similar patterns. Results indicated that physicochemical changes accompanying muscle contraction affected protein network formation during gelation.