The Influence of Nutrition on Collagen Metabolism and Stability

Collagen is the major connective tissue protein and accounts for about 30% of the total protein in the mammalian body. Together with proteoglycans and elastin, it forms an extracellular matrix providing structural support and a mechanism for transmitting force for virtually all organs including muscle. The collagen content of most skeletal muscles is relatively low (about 2% or less) compared to other tissues such as skin, bone and cartilage; however, collagen plays a major role in determining the textural properties of meat (Light, 1987; Bailey, 1988). The collagen characteristics related to muscle texture include tensile strength, thermal shrinkage and melting temperature, and degree of solubility under various conditions. These characteristics are a function of collagen synthesis and changes occurring after synthesis. It has been difficult to establish the relationship between nutritional factors and collagen metabolism and structure. Tinker and Rucker (1985) suggested that the intraand extracellular nature of metabolic events governing collagen synthesis, the long biological half-life of some collagen proteins, the influence of non-nutritional factors and the relationship of time to changes in collagen make elucidating the contribution of a nutritional factor(s) to collagen metabolism difficult. Nonetheless, nutritional factors do affect metabolism, synthesis and functional properties of collagen; the functional properties of collagen have a significant effect on meat texture (Light, 1987; Bailey, 1988). With efficient production of lean but tender muscle a priority, the role nutrition plays in collagen development requires attention. The objective of this presentation is to examine selected nutritional factors and the mechanisms by which they may affect synthesis, degradation, accretion, and physical properties of collagen.