Effect of Feijoa Leaf Polysaccharides on the Physicochemical and Sensory Properties of Low Fat Yogurt during Storage

Background and Objectives: In this study, due to the ability of polysaccharides to modify rheological, physical and chemical properties of food products, the effect of feijoa leaf polysaccharides (FLPs) on the physical, chemical and sensory properties of low-fat yogurt during 20 days of storage was investigated. Materials and Methods: Different concentrations of FLPs (1.5, 2.5 and 3.5% w/w) were mixed with low-fat standardized pasteurized milk. Then, 3% of commercial starter culture was added to the mixture. After completing the process of yoghurt production, the pH, titratable acidity, syneresis, viscosity, and sensory properties of low-fat yogurt were evaluated during the storage period in the refrigerator. All the experiments were performed in triplicate. Results: pH and syneresis decreased while titratable acidity and viscosity increased by the addition of FLPs in low-fat yoghurt formulation in comparison to the control sample throughout storage. As the concentration of FLPs increased, the color, flavor and total acceptance scores decreased, while the texture score increased. The low-fat yogurt containing 1.5% of FLPs obtained the highest total acceptance score. Conclusion: The FLPs can be used as a natural, low-cost and valuable functional compound in the food industry, especially in the preparation of low-fat dairy products to improve physical, chemical and sensory properties.