SELECTED RHEOLOGICAL PROPERTIES OF AQUEOUS CASEINATE - POLYSACCHARIDES DISPERSIONS

The objective of this research study was to obtain protein - polysaccharides mixtures that could replace fat in low-fat products. During the first stage, the effect was determined of the carrageenan on rheological properties of sodium and calcium caseinates; next, the system was enriched by adding a modified starch. The Mixtures obtained were used in the production of a processed cheese analogue; their effect was determined on the rheological properties and meltability of the product. Using a dynamic rheometer RS 300, there were measured rheological properties of the protein - polysaccharide mixtures heated to a temperature of 85 degrees C and, then, cooled to 8 degrees C. The texture of the processed cheese analogues was analysed using a texture analyzer TA-XT2i. The addition of x-carrageenan caused the value of storage modulus (G ') of the solutions of sodium and calcium caseinates to increase. The mixtures of sodium caseinate with 0.2 % and 0.3 % addition of carrageenan were characterized by the highest hardness of ca. 0.35 N. Interactions between casein and carrageenan probably determined the increase in the hardness of the protein - polysaccharide gels, whereas the starch constituted a space filler of the gel network. The mixtures of the caseinates with the carrageenan and starch can be used to produce processed cheese analogues of appropriate rheological properties and proper meltability.