CONICET | Buscador de Institutos y Recursos Humanos

Proteins whey is a by-product of cheese manufacture. Whey proteins are of globular nature and heating induces denaturation and aggregation. Formation of whey protein gels and their properties are influenced by many factors: pH, protein content, ionic strength, rate and temperature/time of heating, types and ratios of the serum proteins, concentration of divalent ions (e.g. Ca+2), among others. Another factor that affects protein gelation is the addition of polysaccharides. Polysaccharides are often added to modify the texture and microstructure of whey protein gels. Carrageenans are polysaccharides widely used as thickening, gelling and stabilizing agents, particularly in the dairy industry. Functional properties of carrageenans are straightforward related to their structure. In this work, the whey proteins were recovered applying ultrafiltration and diafiltration technology and whey protein concentrate (WPCc) with 77.83% of protein content was obtained. The effect of the temperature (45 °C and 90 °C) and the presence of CaCl2 10 mM, on the structural, rheological and textural properties of mixed gels formulated with different protein concentration (0.5, 1, and 3% w/v) and carrageenan at 1% (w/v) of concentration at pH 7 was studied. SEM micrographs revealed an aggregate protein in the gel matrix. Dynamic rheology studies indicated that the proteins weakened the carrageenan network in gels without CaCl2. The temperature as unique variable did not have an effect. The highest G', hardness and adhesiveness corresponded to gels formulated with CaCl2. Gels at high protein concentration presented the lower adhesiveness. All gels showed a high water holding capacity. The different variables used to prepare these gels, allowed to obtain strong and high elastic mixed gels.