The application of enzymes in dairy products

The main application of enzymes in dairy products is the application of proteases, especially the processing of cheese with rennet, and the decomposition of lactose with lactase to improve the digestibility of dairy products by people with lactose intolerance. 

Lactoperoxidase Fresh milk and dairy products have also been widely used domestically and internationally. The following is an overview of the application of the above three enzymes in dairy products.

(1) Mik-clothing enzymes

Cheese is a kind of fermented milk product made from milk and milk products, adding a certain amount of lactic acid bacteria and rennet to coagulate the protein in the milk, excluding the whey, and then maturing for a certain period of time. During the production and maturation of cheese, enzymes play a very important role in improving its tissue structure, flavor and nutritional value. These enzymes can be divided into three categories according to their sources:

• Enzymes added to milk; 
• Enzymes inherent in milk; 
• Enzymes produced by starter.

The enzyme added in cheese production is rennet, whose function is to promote the coagulation of milk protein and increase the yield of the product. The rennets currently added include animal rennet, plant rennet and microbial rennet. 

See the following table: Animal rennet is the earliest type of enzyme used in cheese production. Cheese produced with it is superior to other enzymes in terms of flavor, texture and yield. 

The calf rennet used in traditional cheese production contains 75-95% pure rennet and 5-25% pepsin. 

Because pure rennet has higher curdling properties than pepsin, the protein is decomposed better during cheese maturation and will not cause bitterness due to excessive protein decomposition. Therefore, cheese manufacturers prefer to use higher pure rennet Rennet.

(2) Alkaline protease

Casein is an important component of milk, and its essential amino acid composition is reasonable. 

For example, it is rich in lysine, which is a good animal protein, but casein is also unsatisfactory when it is digested and absorbed, mainly because it easily forms a large clot in the stomach, which affects the human body, especially infants.

Children's absorption and utilization of it. After using alkaline protease to hydrolyze the milk protein, it was found that its solubility index increased significantly, indicating that the milk protein (especially casein) was hydrolyzed to generate some low peptide molecules, which changed the nature of the milk protein, which would facilitate the digestion and absorption of casein by humans. 

And recently, it has been discovered that some peptide molecules in casein hydrolysate also have certain functional effects. At present, people have done a systematic study on the enzymatic degradation of casein, and have determined the temperature, time and enzyme-substrate concentration ratio of the enzymatic reaction.