Effect of hydrocolloid type and concentration on flow behaviour and sensory properties of milk beverages model systems

Formulation of low-calorie flavoured milk beverages involves the use of hydrocolloids to obtain an acceptable mouthfeel. Sodium alginate and κ-carrageenan are the most commonly used. In this paper, the rheological behaviour of model solutions containing either of these two hydrocolloids, with or without the addition of sucrose, in water or milk, has been studied. All solutions fitted well to the Ostwald de Waele model. The analyses of variance showed that in κ-carrageenan solutions, the effect of the medium–hydrocolloid interaction on both flow index (n) and apparent viscosity at 1 s⁻¹ (η₁) was significant. Milk-based solutions were more pseudoplastic and more viscous than the aqueous solutions, due to the well known κ-carrageenan–casein molecular interaction. In alginate solutions, the medium–hydrocolloid interaction was also significant but the differences in both n and η₁ values were of less entity. Sensory viscosity differences of more viscous chocolate milk model systems were well explained by apparent viscosity values at low shear rate (10 s⁻¹), while for less viscous samples apparent viscosity at higher shear rate (300 s⁻¹) values were appropriate. At similar viscosity, κ-carrageenan systems showed better flavour-releasing properties than alginate.