Rheological, textural and structural properties of dairy cream as affected by some natural stabilizers

Abstract

The effects of whey protein, basil seed gum (BSG), and κ-carrageenan (CGN) on the structure–rheology interactions of low- and high-fat cream were investigated. Pseudoplastic and thixotropic behavior of cream was found for all the samples and the pseudoplasticity was increased with an increased level of stabilizers. The apparent viscosity (ηa) of the forward curves is greater than that of the backward ones, which may be the result of the breakdown of the fat globule structure under shear stress. The viscosity of cream was reduced, while using a stabilizer (BSG/CGN) can be related to the water binding of hydrocolloid molecules contributing to resistance in flow. For all samples, elastic modulus was greater than viscous modulus, indicating a greater contribution from elastic characteristics. With the increase of BSG/CGN levels, the molecules may be competitively adsorbed onto the surface of fat droplets, thereby changing its surface tension and decreasing its particle size. Increases in whey proteins, fat, and BSG also significantly increased hardness, whereas increases in CGN significantly decreased it. The globular aggregates in the microstructure of high-fat dairy cream were smaller than those in low-fat dairy cream, allowing more water to be retained in the high-fat samples. Therefore, synergistic interactions between polysaccharides and proteins may encourage the formation of a cross-linked network.