الفهرس 
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Abstract
This study was carried out at Dairy Chemistry Department, belonging to the Animal Production Research Institute (APRI) in cooperation with Dairying Department, Faculty of Agriculture, Mansoura University, during the period from November 2016 to January, 2018 . Yoghurt manufacture from cow’s milk which separated into three replicates treatments as well as protein goat’s additive with 0, 1, 2 and 3%. Zabadi was manufactured and pH, acidity, Fat content, Total nitrogen, pH values, Ash content and Total solids content were determined. The obtained results could be summarized as the following: Part (I) 1. Gross chemical composition of milk: The average acidity value of Zaraibi and Damascus goat’s milk was 0.16%, whereas pH was 6.66. The average composition of Zaraibi milk revealed that values of TS, fat, protein and lactose contents were 10.55, 3.81, 3.93 and 2.81%, respectively. 2. Functional properties: Foaming capacity in case of Damascus goat’s milk were 120, 130 and 140 (20, 25 and 45%) in the casein presence whereas the corresponding values in Zaraibi goat’s milk were 130, 135 and 155 (30, 20 and 50%) at pH 4, 6 and 8 using HCl protein preparation. 3. Emulsification properties: The emulsification of casein preparation in case of Damascus goat’s milk were 20.34, 20.17, 19.97, 19.73 and 19.23 after 1, 2, 3, 4 and 5 days respectively, in the casein presence preparation with HCl on pH 4 whereas the corresponding values were 17.95, 17.93, 16.76, 19.45 and 15.41 at pH 6 and 18.76, 17.55, 16.54, 16.06 and 15.41 at pH 8. The corresponding values Zaraibi goat’s milk of casein were 16.55, 16.19, 15.76, 15.41 and 15.04 on pH 4; 17.80, 17.03, 16.76, 16.31 and 16.05 on pH 6 and 19.75, 19.10, 18.23, 18.04 and 17.97 on pH 8, respectively. 4. Oil and water absorption capacity: Oil absorption capacity of casein preparation in case of Damascus goat’s milk were 1.041, 1.080 and 2.076 at pH 4, 6 and 8, respectively. The corresponding values for Zaraibi goat’s milk were 1.040, 1.168 and 1.054 at pH 4, 6 and 8, respectively. 5. Solubility (%): The solubility of casein preparation in case of Damascus goat’s milk were 82.30, 86.69 and 88.32% at pH 4, 6 and 8, respectively. The corresponding values for Zaraibi goat’s milk were 8.94, 87.08 and 90.45% at pH 4, 6 and 8, respectively. PART (II): 6. Manufacture of Zabadi from cow’s milk by the amount of milk goat’s protein concentrate (WPC) added: The recorded pH values at zero time were 6.44, 6.28, 6.41 and 6.41 when WPC was added at the rate of 0, 1, 2 and 3% respectively. After 30 minutes of incubation, the corresponding pH values were 6.09, 6.12, 6.00 and 5.89 in order, but such differences were insignificant. The recorded CT in fresh Zabadi were 20.2, 25.3, 28.32 and 32.00 g when WPC was added at the rate of 0, 1, 2 and 3% respectively. The corresponding values in the stored Zabadi were 23.16, 27.40, 32.01 and 36.80 g in order. Curd syneresis (CS) of the fresh and stored Zabadi as affected by using different amount of WPC in making Zabadi. In case of the fresh Zabadi, the amount of the exudate were 4.34, 3.95, 2.08 and 1.92 g after 10 min. The corresponding values were 6.20, 5.44, 3.57 and 3.21 g after 30 min and 7.35, 6.63, 5.08 and 4.40 g after 60 min when WPC was added at the rate of 0, 1, 2 and 3% respectively. For general appearance, the control samples had the lowest value (7.67 out of 10 points), whereas the treated samples had 8.5, 9.35 and 10.0. Points when WPC was added at the rate of 1, 2 and 3% respectively. This means that increasing the amount of WPC added significantly improved appearance of the resultant Zabadi. This was also noticed with respect to firmness of the curd. The given score was 7.01 out of 10 for the control Zabadi and 7.67, 8.35 and 9.35 for Zabadi samples treated with 1, 2 and 3% WPC respectively. In conclusion, using WPC with 3% goat’s protein content greatly improved the organoleptic properties of full-fat cow’s milk Zabadi.