استخلاص و تنقية و توصيف و ربط ببسين الدجاج و استعمالها في صناعة الجبن الأبيض الطري

الملخص EN

The present study aimed to isolate pepsin enzyme Ec: 3.4.23.1 from some animal sources and purified it and Studied it’s characteristics and immobilized it as well as it’s practical applications in food industry.

The enzyme was extracted from the stomach of three animal sources (Sheep, Chicken and Nuwaibi fish ) using five extraction solutions including distilled water , Sodium chloride (10%) solution , Sodium chloride (6%) Boric acid (2%) solution ,Sodium Phosphate 0.1M and an pH 7.3 solution and Tris-acetic acid 0.4M and an pH 7.6 solution in order to find out the best source of enzyme and the best extraction solution .Sheep's stomach was the best source of enzyme, Sodium chloride (6%) Boric acid (2%) solution was the best extraction solution which gave highest specific activity 14.3 unit / mg .Protein content for the crude enzyme extracts were con centrated using saturated ammonium sulfate in arrange 30- 70% , 20-90% and 20-60% for Sheep, chicken and Nuwaibi fish pepsin respectively.

Dialyzed Chicken pepsin possesses the highest proteolytic activity .

The dialyzed chicken pepsin Immobilized study with four carriers including Silica gel,SRF Resinous ,Calcium Alginate and Agar showed that the best carrier was agar which gave the maximum Immobilized efficiency 67%.The best optimum concentration for Immobilize dialyzed chicken pepsin with agar was 3% with the highest proteolytic enzyme 75%.

The purified sheep pepsin was Immobilized with agar in 3% concentration .The remainder enzyme activity for agar Immobilized pure Sheep pepsin and dialyzed Chicken pepsin were 25% , 21% respectively after 7 times using and the remainder enzyme activity for agar Immobilize pure Sheep pepsin and dialyzed Chicken pepsin were 22%, 27% respectively was stored for 60 days in 4 °C.

The optimal pH for clotting activity for free and Immobilize dialyzed Chicken pepsin was 5.8.

The optimal pH for the stability of free and Immobilize dialyzed Chicken pepsin are 3.The optimal temperature for clotting activity for free and Immobilize dialyzed chicken pepsin was 35 ◌C .The optimal temperature for free and Immobilize dialyzed Chicken pepsin stability was 15-45°C.

Agar Immobilized dialyzed making Chicken pepsin was utilized in soft cheese results revealed that the Chemical composition and organoleptic evaluation of cheese was compatible with cheese produced in traditional methods, This result is an indicator to enzyme efficiency in soft cheese and the possibility to use it as Calf rennet alternative and it can be used for more than one time in cheese making.