Myofibrillar protein from different muscle fiber types: implications of biochemical and functional properties in meat processing.

Texture, moisture retention, and tenderness of processed muscle foods are influenced by the functionality of myofibrillar protein. Recent studies have revealed large variations in processing quality between red and white muscle groups that can be attributed to differences in the functional properties of myofibrillar protein associated with the type of fiber. Myofibrillar proteins from fast- and slow-twitch fibers exhibit different biochemical and rheological characteristics and form gels with distinctly different viscoelastic properties and microstructures. The existence and wide distribution of the numerous myosin isoforms in different muscle and fiber types contribute to the various functional behaviors of myofibrillar protein. The different sensitivities of fast and slow myofibrillar proteins to pH, ionic environment, temperature, and other external factors have been well documented and illustrate the importance of adjusting meat processing conditions, according to fiber type profile to achieve maximum protein functionalities, and hence, uniform quality of the final muscle foods.