EFFECT OF ADDITION OF CARRAGEENAN ON RHEOLOGICAL BEHAVIOUR OF YOGURT

摘要

The purpose of this work is to study the effect of addition of k-kappa carrageenan and i-iota carrageenan on the rheological behaviour of different types of yogurts. The role of concentration as well as the type of carrageenan used (k-kappa carrageenan and i-iota carrageenan) has been analysed.The most common technique used for rheological liquids is Viscometers, measuring shear strength, described by the coefficient of viscosity. The most common technique used for rheological liquids is Viscometers, measuring shear strength, described by the coefficient of viscosity. For this study, the yogurt samples were obtained in the laboratory using the cultures starter DIPROX YBA 986. The effect of addition of carrageenan in yoghurt was investigated by a rotational viscometer, Brookfield viscometer (Brookfield Engineering Inc, Model RV – DV I Prime) with RV spindles. The Brookfield viscometer DV I Prime with disk spindles represents an easy and cheap method for the rheological characterization of non-Newtonian fluids, in this case of yoghurt. The cluster analysis was performed using Unsrambler X version 10.1 (CAMO Process As, Oslo, Norway, 2005), all the rheological and physicochemical parameters were weighed and normalized for performing the cluster analysis. In the case of yogurt samples obtained in the laboratory, the addition of carrageenan increases the viscosity. i-iota carrageenan has been evaluated as more effective for increasing the viscosity of yogurt in comparison with k-kappa carrageenan (with the same concentration).