الفهرس 
Chemical composition of camel and cow milk proteinsOnly 14 pages are availabe for public view
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Abstract
The functional properties of proteins in relation to food refer to those physico-chemical properties of protein which affect the functionality of the food, i.e. its texture (rheology), colour, flavour, water sorption/ binding and stability. Probably the most important physico-chemical properties are solubility, hydration, rheology, surface activity and gelation.
Milk proteins, by virtue of their heterogeneity, range of physical properties and amphipolar characteristics, are the premier proteins used in food processing for multiple functions. Therefore, bovine milk caseins and their derivatives are extensively used in food industries because of their physico-chemical, nutritional, and functional properties, which make caseinates useful ingredients in complex food preparations. Thus, they are added to different products because of their high emulsifying, water-binding, and gelation capacities, their resistance to heat treatments, and their contribution to the food texture and juiciness. Some of these properties make caseinates useful ingredients both in the preparation of bakery and confectionary products, where they can be used as milk substitutes. In addition to that, from the nutritional point of view, caseins have all the essential amino acids and an important function in the transport of calcium and phosphate, representing an easily digestible source of nutrition, contributing to a carefully balanced diet especially for specific foods as infant formulas, sport foods.
Therefore, this study aimed at evaluating different functional properties of both camel and cow milk proteins in order to gain some knowledge help in using such proteins in different food applications. To achieve such goals, various casein, casein co-precipitate and whey proteins preparations were prepared by different methods. Meanwhile, the effect of some factor as concentration of protein, pH of the medium, trypsin treatment on functional properties of prepared proteins was studied. The obtained results revealed the following:
1. Cow milk proteins have higher degree of solubility than those of camel milk proteins.
2. The solubility of both camel and cow milk protein was protein concentration and pH dependent, i,e. the higher the concentration and pH value, the higher solubility.
3. Camel and cow HCl-casein showed the highest solubility at pH 8.0 followed by whey proteins then casein co-precipitate. But casein co-precipitate was characterization by very low solubility at all pH values comparing to other caseins.
4. The EC of both camel and cow milk protein was protein concentration and pH dependent. The higher the concentration and pH value, the higher the EC.
5. The EC values of cow milk proteins were significantly higher than there of camel milk proteins. This difference in EC value is mainly due to the differences in structure of protein.
6. The order of EC of both camel and cow milk protein among the three proteins preparation was HCl-casein > whey proteins> casein co-precipitate.
7. The viscosity values of cow milk proteins were significantly higher than those of camel milk proteins.
8. At all pH values, the ascending order of viscosity of camel and cow proteins was whey proteins, HCl-casein and casein co-precipitate.
9. Camel and cow whey proteins showed the highest foaming capacity (FC) at pH 8.0 followed by HCl-casein then casein co-precipitate.
10. Camel whey proteins has higher degree of FC and FS than those of cow whey proteins.
11. There were no significant differences in FC values between camel and cow HCl-casein.
12. The highest foaming capacity of camel or cow proteins 1.0 % and pH 8.0.
13. The behaviour of foaming property in both camel and cow milk casein is concentration and pH dependent.
14. There was a significant decrease in both camel and cow milk whey proteins FC due to the trypsin treatment. The decrease in FC was time dependent.
15. There was a significant increase in FC of cow milk casein co-precipitate than that of camel milk before and after trypsin treatment.
16. The trypsin treatment for 5, 15 min resulted in decrease in foaming properties of both camel and cow milk HCl-casein, whey proteins and casein co-precipitate.
17. The FS of camel casein co-precipitate was lower than that of camel whey proteins and HCl-casein. The trypsin treatment resulted in decreasing the FS of camel milk casein co-precipitate.
18. There were significant increases in both camel and cow milk HCl-caseins, whey proteins, casein co-precipitates solubilities. Meanwhile the increase was directly proportional with time. The solubility increase was time dependent.
19. The viscosity of both camel and cow milk HCl-casein, whey proteins and casein co-precipitates was significantly increase by trypsin treatment. The viscosity increase was time dependent.
20. The modification of both camel and cow milk HCl-caseins, whey proteins and casein co-precipitate resulted in significant decrease in EC property. Cow milk proteins are better than camel milk proteins in EC property.
Conclusion and Recommendation
1. Camel and cow milk protein preparations are highly different in their functional properties.
2. Camel milk protein preparations are characterized by their higher foaming capacity and stability than those of cow milk protein specially whey proteins, therefore they can be used in ice cream making, coffee whitener, foam milk and whipped toppings.
3. Cow milk proteins are characterized by their higher solubility. EC and viscosity than camel milk protein, therefore they can be used in food application as beverage, baking , candy, soups and sausages.