In the technological process of production of variousfermented milk products and certain types of cheese for ripening milk, a liquid rennet enzyme is used. It is made by processing a certain section of the stomach of newborn calves and lambs. Due to the fact that the gastric system of young animals is not yet developed enough, the abomasum (this is what is called the digestive system necessary for processing), plays the role of an indispensable starter.
Milk consists of proteins of casein and albumin.The first group is about 80% of the total mass and is presented in the form of multimolecular compounds. Such components are in the form of protein balls and are called "micelles". They can include different kinds of casein.
When milk is curtailed under the influence ofof certain enzymes, micellar changes occur, as a result of which pairs of k-casein and a macropeptide are formed. In this case, the k-casein remains in the micelles, and the macropeptides are transformed into a liquid fraction (serum). In the process of coagulation, molecular compounds of k-casein are glued together, forming a milk clot.
Traditional production technologiessour milk products determine the use of coagulants - enzymes involved in the process of converting milk into a clot, which can then be easily separated from the serum. From the correct choice of coagulant and its dosage depends consistency, shelf life, aging time and flavor characteristics of the finished product. Usually, the following are used as milk enzymes:
In home-made cheese-making as the maincoagulant often use liquid rennet enzyme Ceska Lase Kalase. This product consists of a fine-caking natural enzyme. It is used to prepare any kind of home-made cheeses and cottage cheese from natural milk.
As a result of the action of a coagulant of this typecoagulation of milk protein occurs. Homogeneous milk mass is divided into two fractions: acquires a consistency of gel and whey. It is the transformation of milk into a clot and is the main task of a natural enzyme.
Organic compounds consisting of pepsin andchymosin, allow to make the technological process of coagulation of milk in a short period of time. Already after the first phase of coagulation, a lot of milk clots are obtained, when grinding, they get cottage cheese.
Cheese making is a rather lengthy processmore difficult. Under the action of a powder or liquid rennet Ceska Lase enzyme, cleavage of casein occurs, and during the maturation of cheese the product acquires a specific cheese flavor.
After separation of the resultingcoagulation of clots from liquid whey, they are placed in special forms and pressed. The resulting semi-finished product is sent to a special pickle and kept in it for 10 days. Only after this, the young cheese is sent for ripening.
However, very often, along with the popularcoagulant, cheesemakers use and other brands of natural liquid rennet enzymes. Clerici, Meito, Normal, Extra - these are the basic, widely used in home and industrial cheese making, natural enzymes. They may differ slightly in the activity of IMCU (International Milk of Conversion Units) under different qualitative and physical characteristics of the feedstock.
Methods for producing calf liquid rennetenzyme, directly related to the destruction of newborn animals, is not only absolutely inhumane, but also not economical. Despite the high cost of natural coagulant, the killing of a young calf does not enable the growing of an animal and excludes the profit from the sale of its meat.
In addition, many consumers who know thatsuch a rennet enzyme and how it is obtained, refuse to eat foods that have been used in the preparation of such raw materials. Therefore, the question of replacing the use of veal coagulant has been standing for a long time.
Today, thanks to microbiologicalresearch, there are some options for replacing the use of veal abomasum. Developments of foreign and Russian scientists are widely used in the technological processes of cheese production and various fermented milk products.
In our country, as in the whole world, the largestpopularity acquired microbial enzymes. Sourdoughs, the production of which is based on the use of certain types of fungi and lactic acid bacteria, is often considered to be a more effective way of obtaining quality cheeses of different types.
Leading brands usedalmost everywhere in Europe and in Russia, are considered the development associated with the life of strains of milk fungi Rhizomucor meihei and yeast Kluyveromyces lactis.
In addition to enzyme preparations of animal andmicrobial origin, and extracts of certain plants can also be used as coagulants. Coagulation of milk with the help of fig tree juice (Ficus carica), often used in the regions of its growth, has long been known throughout the world. Another example of plant enzymes used in the dairy industry is the aqueous extract of cardona flowers, which is widely used in the production of Portuguese cheese Sena da Estrela.
Despite the low cost of plant raw materials,these technologies have not yet been widely used. This is due to the fact that plant coagulants do not provide an opportunity to obtain the optimal yield of finished products. It can not be said that microbial enzymes always produce the expected result. That is why natural rennet coagulants, thanks to the possibility of obtaining high-quality products with stable indicators, have not lost their popularity so far.
