The sensory characteristics and rheological properties of soups containing oat and barley β-glucan before and after freezing

The aim was to study the effect of concentration and molecular weight of two oat and one barley beta-glucan preparation on the perceived sensory quality of a ready-to-eat soup prototype before and after freezing. Oat1 was a bran-type preparation containing high molecular weight beta-glucan; Oat2 and Barley were more processed and purified preparations with lower molecular weight. Nine soups containing 0.25-2.0 g beta-glucan/100 g soup and one reference soup thickened with starch were profiled by a sensory panel and their viscosity and molecular weight of beta-glucan was analysed. Freezing had no notable effects on the sensory quality of the soups. At the same concentration, soups made with the bran-type preparation were more viscous and had higher perceived thickness than soups made with processed, low molecular weight preparations. Barley soups had mainly higher flavour intensities than oat soups. Good correlations were obtained between sensory texture attributes and viscosity (r=0.70-0.84; Pless than or equal to0.001) and moderate correlations between flavour attributes and viscosity (r=-0.63--0.80; Pless than or equal to0.001). Technologically, beta-glucans are feasible thickening agent alternatives in soups. Preparations with lower molecular weight and viscosity are easier to add into a food product in higher quantities, but the role of high molecular weight beta-glucan in physiological functionality has to be kept in mind. (C) 2004 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.