Chemical Interactions of Nonmuscle Proteins in the Network of Sardine ( Sardina pilchardus) Muscle Gels

The present work examines the formation of different types of chemical bonding in sardine gels made with added proteins (egg white, soy, casein, gluten) at various temperatures, and possible interactions between myofibrillar and nonmuscle proteins in the gel network. The contribution of ionic and hydrogen bonds to thermal aggregation was not found to be decisive. Hydrophobic interactions in gels with egg white were significantly lower than in gels with other nonmuscle proteins. In gels with casein this protein was found to be largely nonspecifically associated with the myofibrillar proteins at high temperatures. The insolubility of the gluten proteins made it difficult to elucidate a possible interaction with the myofibrillar proteins.