الفهرس 
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Abstract
Fish industry produces approximately 60% of the total fish weight including head, skin, scales, fins, dorsal and viscera. It is an unexploited waste which is rapidly corrupt generating a serious environmental pollution problem, whether in developing or developed countries. Although these wastes are good source of essential nutrients, especially protein, they are normally used to manufacture of feed for animals and fertilizers and is of small economic value. Fish viscera is represent about 5% of the total mass of fish, which is a good source of vital compounds, especially digestive enzymes, such as proteolysis enzymes, like Trypsin, Chemoterpsin and Elastase. These enzymes are used extensively in food processing, as the demand for these enzymes has increased in recent years, mainly alkaline proteolysis enzymes, which are used to improve the quality of meat. Meat quality can be defined as a combination of various characteristics of fresh and processed meat. These characteristics include both sensory and technological characteristics, such as color, texture, water holding capacity, cooking loss and shrinkage. Therefore, this work is designed to extract the alkaline proteolysis enzymes from the viscera of Silver carp fish and determined their characteristics. Then used these enzymes to prepare short-chain bioactive polypeptide SCBPP from fish offal and flesh that having molecular weight less than 30KDa. The produced SCBPP were used as natural antioxidant in minced beef during 12 weeks of frozen storage instead of synthetic antioxidant. Also, use these enzymes as an aid to softening of hard-to-cook camel meat chunk. The obtained results are: Firstly: characterization of crude alkaline proteases preparation (CAPP) 1. The Tris-HCl buffer was the best buffer for the CAP prepared activity extracted from the viscera of Silver carp fish rather than Na2HPO4 buffer. 2. Optimum pH for the CAP prepared activity extracted from the viscera of Silver carp fish was pH 8.5. 3. Optimum temperature for the CAP prepared activity extracted from the viscera of Silver carp fish was 45ºC. 4. The best concentration for CAP prepared to substrate ratio to rich the optimum activity was 1enzyme protein to 5 substrate protein. 5. The thermal stability of CAP prepared was between 35ºC- 55ºC, and inactive at 60ºC. 6. The pH stability of CAP prepared was between pH 7.5 - 10.0 while its activity was lost at pH 11. In conclusion, optimal conditions for the activity of crude alkaline proteases preparation CAPP extracted from Silver carp fish are the use of 0.2M Tris-HCl buffer at pH 8.5 and 45ºC, when the substrate to enzyme concentration is 1:5 (enzyme protein/substrate protein). While the enzyme activity is lost when the temperature is raised to 60ºC for 30 minutes or pH is below pH 7 or above pH 10 for 30 minutes. Secondary: Purification of CAP 1. The best activity of the CAP prepared extracted from the viscera of Silver carp fish when it is purified by ammonium sulphate solution with 40% saturation. 2. The fourth fraction (millilitre collected after the fourth minute) was given the highest enzyme activity, when the CAP prepared, extracted from Silver carp fish, purified using gel filtration technique onto column filled with Sephadex G-50. 3. SDS-PAGE technique for CAP prepared purified with gel filtration using the SphedxG-50 column shows that there are 3 types of protein fractions having 19, 27 and 48kDa. 4. Using SDS-PAGE technique for CAP prepared purified by ammonium sulphate (40% saturation) display that it contains four protein bands with MW 7, 21, 27 and 63kDa. 5. Purified CAP prepared, extracted from the viscera of Silver carp fish, using Ultrafiltration technique on a polyamide membrane (cut-off 30KDa), give the highest enzyme activity compared to the other purification methods (ammonium sulphate precipitation and gel filtration). 6. Protein fractionation of CAP prepared, extracted from the viscera of Silver carp fish, using SDS-PAGE technique, revealed that CAPP contains 6 types of proteins having molecular weight (MW) fluctuated from 5 to 76 KDa, but the main proteins have a MW of 5, 20, 25 and 48KDa. 7. SDS-PAGE technique for CAP prepared purified with Ultrafiltration using polyamide membrane (cut-off 30KDa) has one of protein band with MW of 24kDa. Third: Determination of antioxidant activity (AA%) of the short-chain bioactive polypeptides SCBPP by DPPH in protein hydrolysate produced from the action of crude enzyme CAP prepared on Silver carp fish offal. 1. The ability of protein hydrolysate produced from Silver carp fish offal which contains SCBPP increases as antioxidants by extend the time of CAP prepared action, where the highest antioxidant value is obtained after 7 hours of hydrolysis.The maximum antioxidant activity of fish protein hydrolysate is achieved by commercial Trypsin after 4 hours of proteolytic degradation. 2. The ability of protein hydrolysate produced by the action of the CAP prepared on the Silver carp flesh containing SCBPP increases as an antioxidant by prolonging the action time of CAP prepared. The highest antioxidant value is obtained after 4 hours of hydrolysis. The maximal antioxidant activity of the protein hydrolysate by commercial Trypsin is achieved after 3 hours of hydrolysis. 3. It was observed that there were a large number of high molecular weight proteins (more than 63 kDa) in the early hours of analysis, which decreased as the hydrolysis continued with the increase of low molecular weight proteins until reaching the small molecular weight proteins (in the range of 5 ~ 25 KDa) for both protein hydrolysate, whether from fish offal or fish flesh. Fourth: Applications of the use of the crude enzyme CAP prepared in the field of food processing: 1. The obtained results show that the short-chain bioactive polypeptides SCBPP found in proteins hydrolysate prepared by CAP prepared can reduce the concentration of TBArs compared to control samples during 12 weeks of frozen storage. 2. TBArs of minced beef free from SCBPP (control) is ranged between 0.96~1.11mg MDA/Kg beef, which is higher than that of permissible limit according to ES (2013). At the same time minced beef containing 3mg SCBPP/kg beef fluctuated from 0.56~0.75mg MDA/Kg beef after 8 weeks under the same conditions of storage. 3. The ability to retain water in the camel meat chunk (WHC) is reduced due to the presence of the enzyme in the steeping liquor, where the value of cooking loss (CL%) increases due to prolongation of the time of the enzyme action. In general, the effect of commercial Trypsin is more pronounced than that crude alkaline protease preparation (CAP). Similar, cooked meat shrinkage CMS% is increased parallel with cooking loss CL%. 4. As for free amino acids, it is clear that the concentration of FAA% gradually increased by increasing the time of soaking. the camel meat chunk in the enzyme-containing solution (either of CAP prepared or commercial Trypsin) until it reached its highest concentration after 6 hours. The results show that the effect of the commercial Trypsin is more pronounced than that of the CAP prepared enzyme that prepared from the viscera of Silver carp fish.