الفهرس 
REVIEW OF LITRATUREOnly 14 pages are availabe for public view
Abstract
Transglutaminase is an enzyme that forms crosslinks between protein molecules. This cross linkage has unique effects on protein properties. Transglutaminase is now widely used in many food products as well as dairy products. Both of cow’s milk and soybean milk has been shown to be a very good substrates for transglutaminase. These days, it seems that the most advanced area of dairy products processing using transglutaminase are yoghurt and cheese products.
There is very little published information on the effect of transglutaminase on products that combine both of cow’s milk and full fat soy milk. So, the objective of the present study was to gain better information regard the effect of transglutaminase on some characteristics of dairy products like yoghurt or soft cheese manufactured with cow’s milk and full fat soy milk.
This study conducted in two parts:
Part I: Yoghurt manufacture
In this part yoghurt manufactured by cow’s milk, soybean milk or mixture of both (1:1, 1:2 and 2:1) treated by transglutaminase (0.5, 1 and 1.5 u/g protein), using classic starter culture of yoghurt (Lb. delbreuckii ssp. bulgaricus and Str.thermophilus). The results obtained were summarized in the following:
1. Transglutaminase improves the viscosity of yoghurt obtained specially in high doses (1 or 1.5u/g protein).
2. Syneresis defects was reduced by using transglutaminase.
3. The curd strength was increased by using transglutaminase enzyme.
4. The curd structure was improved and became compact with good distribution of protein and fat as seen in the electron microscope examination pictures.
5. Using transglutaminase was a good processing step for the manufacture of a high quality yoghurt.
6. Sensory evaluation for soy yoghurt produced was enhanced markedly comparing with yoghurt manufactured by 100% soy milk and untreated by transglutaminase.
7. Colour of yoghurt samples were improved and be whiter regarding to the transglutaminase dose used and amount of soy milk added in the mixture.
8. Flavour compounds including some of off-flavours reduced by using transglutaminase and it appear markedly in yoghurt manufactured by 100% soy milk with treated by transglutaminase.
9. In the case of using high doses of the enzyme in yoghurt manufacture the type of stirred yoghurt is preferred.
Part II: Cheese manufacture
In this part, soft cheese manufactured by cow’s milk, soybean milk or mixture of both (1:1, 1:2 and 2:1) and treated by transglutaminase (1, 5 and 10 u/g protein), using acid method for renneting (lemon or acetic acid). The results obtained were summarized in the following:
1- The yield of obtained cheese was higher in case of using lemon juice as a coagulant material or by increasing transglutaminase added.
2- Sensory evaluation of produced cheese samples were improved specially the cheese manufactured by 100% soy milk and treated by TGase compared with untreated cheese.
3- Colour, texture profile analysis, scanning electron microscope and volatile compound profile of cheese treated by the enzyme transglutaminase were improved in the little dose of transglutaminase (5u/g protein).
Finally, the transglutaminase enzyme can be used in the manufacture of some dairy products substituted by soy proteins, in which soybean milk is used as a protein source and transglutaminase doses ranging from 0.5 unit to 1.5 units in the yoghurt industry and up to 10 units in the soft cheese manufacture to improve the properties of these products.