Studying Physicochemical andSensory Properties of Low Energy Yogurt Produced by Adding Inulin

Abstract

This study was conducted to determine the effects of using inulin addition on the physicochemical and sensory properties of fat free low energy yogurt ,inulin was added to skimmed milk in different ratios 0.5, 1.0, 1.5, 2.0 % which reveled to treatments D1, D2, D3 and D4 respectively,In addition to positive control treatment Y+which made from whole milk andnegative control treatment Yـــwhich made from skimmed milk without inulin. The chemical tests that involved the percentage of moisture, protein, fat, carbohydrates, ash, and non-protein nitrogen .The physical tests involved the total acidity, pH, viscosity, spontaneous whey separation and water holding capacity were made beside the sensory evaluation were conducted after processing directly and during storageat (5 ± 1) º C for 14 days .The results indicated that there was increased in moisture content for all treatments made from skimmed milk compared with Y+ treatment. While during storage a simple decrease in moisture contents in all treatments was observed. Fat percentage was low in all treatments made from skim milk compared to Y+.However, the fat percentage was increased in all treatments during storage, carbohydrates percentage was increased in all inulin treatments compared to Y+ and Yـــ treatments. The percentages of protein, non-protein nitrogen and pH values were converged in all treatments.The results of rheological tests showed that Inulin addition improved the viscosity, spontaneous whey separation and water holding capacity, also the results reveled that the inulin addition was improved the sensory evaluation properties of free fat yogurt , specificaly the treatment with 2.0% inulin.