Studying of Physicochemical and Sensory Properties of Reduced Fat Yogurt Manufactured by Adding Beta-Glucan of Barley

Abstract

The current study was conducted and aimed to determine the effect of using             beta-glucan extracted from flour of barley as a replacer for fat on the physiochemical and sensory properties of fat free low energy yogurt by adding beta-glucan to bovine skimmed milk in different ratio of 0.1, 0.2, 0.3 and 0.4% represented by the treatments T1, T2, T3 and T4 respectively, in addition to positive control treatment C⁺ which made from whole milk and negative control C^- treatment in which the yogurt was made from the skimmed milk without beta-glucan. The chemical properties included estimating the percentage of moisture, protein, fat, carbohydrates, ash and non-protein nitrogen, while  the physical properties included total acidity, pH, viscosity, spontaneous whey separation and water holding capacity, in addition to sensory evaluation it was estimated immediately after manufacturing and during storage at (5±1) Cº for 21 days. The results showed that the non-fat yogurt treatments were distinguished by their high moisture content compared to the positive control treatment and during storage a slight decrease in the moisture values ​​was observed for all treatments. Protein percentage , non-protein nitrogen and pH values ​​were non-significant differences for all treatments. The addition of beta-glucan improved the rheological characteristics of yogurt, such as viscosity, spontaneous whey separation and water holding capacity, and also improved the sensory evaluation properties of free fat yogurt, especially the treatment with an addition rate of 0.4% of beta-glucan.