Instrumental Texture Parameters and Solvation Characteristics of Mixed Casein Gels

Caseins exhibit a wide range of physicochemical and functional properties that make them an excellent source of protein for the creation of formulated foods, either as novel or imitative products. Their ability to gel suggests their potential use in highly valued imitative products, such as Kamaboko, a surimi product. However, gelation and the resultant textural properties can be enhanced by various factors, especially the ionic strength of the mixtures and the addition of noncasein proteins. Instrumental texture profile analyses of gels made from mixtures of casein with chicken egg albumin, whey protein concentrate, rennet, and calcium ion were evaluated as well as the solvation characteristics of these protein systems. Of the factors that alter functionality, protein type and Ca2+ concentration contributed most significantly. Whey protein concentrate added to the casein resulted in weaker gels that failed when subjected to 50% compression, but casein gels made with added egg albumin were firm and elastic. The addition of rennet was effective in improving the elasticity of the gels made with casein and egg albumin. The observed improvements in functionality did not lend themselves to the creation of surimi-like products with the formulations studied but suggest the potential for rheological emulation of these products with additional formulation. Received October 18, 1993. Accepted December 5 , 1994. 'Mention of brand or firm names does not constitute an endorsement by the USDA over others of a similar nature not mentioned. (