Effect of whey protein isolate (WPI) as a partial substitution of milk solids not fat (MSNF) in ice cream formula was investigated by replacing 1, 2, 3 and 4% of mix solid not fat. Mixes and resultant ice cream samples were evaluated for their chemical, physico-chemical, as well as the sensory quality attributes. There was no remarkable effect of adding WPI as partial substitution of skim milk powder (SMP) on total solids or fat percentages, while total protein, ash, and lactose content were significantly affected. Specific gravity was affected with the ratio of substitution in both mixes and resultant ice cream and therefore the weight per gallon and overrun percent was significantly changed in the samples. Also, freezing point of resultant ice cream was affected by implementing WPI in ice cream mix. However, the ice cream became smoother and highly acceptable by replacing MSNF with WPI up to 3%. From the data obtained, it could be recommended that ice cream can be produced with high quality by substituting MSNF with WPI up to 3%.

Effect of adding whey protein concentrate (WPC), β-Lactoglobulin (β-LG) and alfalactalbumin (α-LA) on the functional properties of Whipped cream was examined. Obtained results showed unchangeable values of pH, the highest pH was found when skim milk powder was used compared with other treatments. Higher overrun (%) was also found when β-Lactoglobulin (β-LG) and alfalactalbumin (α-LA) were incorporated in whipped cream than whey protein concentrate (WPC). Samples showed changeable values of whipping time .The sensory evaluation showed that treatment with alfalactalbumin (α-LA)was of the most acceptable flavor body & texture and appearance, as compared with other treatments .

Fresh buffalo's milk of 6% fat was heated. Each of three zinc salts (Zinc gluconate, zinc sulphate and zinc acetate) was added to individual milk sample at levels of 30 mg Zn/L milk with the addition to the control treatment. Then, cooled, and inoculcated with 3% mixed culture of Lactobacillus delbrueckii sub sp. bulgaricus and Streptococcus salivarius sub sp thermophilus. and incubated at 42°C until firm curd was formed at pH 4.6. The resultant yogurt was kept in refrigerator (6±1°C) for 10 days. Results showed a reduction in pH values, lactose content and the wheying off resulting in from the prepared yoghurt which supplemented with zinc salts. Whereas, an opposite trend was noticed for acidy, curd tension. While, yoghurt supplemented with zinc acetate recorded the highest value of acetaldehyde content. Moreover the zinc sulphate gained the highest viscosity till the 7 th day of storage. Concerning the sensory properties, enriching yoghurt with zinc gluconate recorded the highest score in flavor, body & texture.

Recently, a focus on the utilization of whey and soya proteins has been receiving significant attention due to their nutritional value and their potential to enhance the functional characteristics of the dairy products. Set yoghurt was manufactured from standardized (4% fat) buffalo milk alone (control), or fortified with whey protein concentrate (WPC), soya protein concentrate (SPC) or their combination (MIX) and stored at 5±2 °C for 10 days. Sensory properties of the resultant yoghurt were evaluated one day after manufacturing. All treatments were analyzed when fresh and during storage period for pH-value, titratable acidity(TA) and syneresis. The pHvalues and titratable acidity(TA) of yoghurt samples showed that both soya and whey proteins did not alter the rate of acid production in yoghurt. Acidity of samples treated with WPC during storage was significantly (P<0.05) higher, compared to control. Also, the addition of whey proteins and soya proteins or their combination resulted in reduction in the syneresis of yoghurt samples by about 17-25%, when compared with control at zero time. Fortification with soya proteins lowered appearance, taste and odor scores by 25, 37 and 35%, respectively, compared with the control. This negative effect of soya proteins on the sensory properties of yoghurt (SPC treatment) was improved when combined with whey protein in the MIX treatment. Therefore, it is recommended to add whey proteins to improve sensory and syneresis properties of soya yoghurt.

The study was conducted to determine the influence of stages of lactation on milk yield and the chemical composition of Zaraibi goats milk in semi-intensive system. The analysis involved a total of 23 milk samples in various stages of lactation (early, midpoint, late). The results indicated that the total yield was (81.6±3.96 kg) in lactation period of 120 days, the daily yield (0.555±0.027 kg), the peak yield (0.78±0.10 kg) in the fifth week, and milk analysis included determination of average (12.81± 0.14 %) total solids, (4.66±0.14%) fat, (3.17±0.07%) protein, (4.18±0.05%) lactose,(8.12±0.08%) solids-non-fat and (0.80±0.02%) ash.