Process for improving the quality of microbial rennet

DETAILED DESCRIPTION What we claim is: 1.
A process for improving the quality of microbial rennet which can be used for making cheese from milk by inactivating cellulase impurities in microbial rennet which comprises heat-treating microbial rennet at a temperature of from about 45.
degree.
to about 90.
degree.
C.
in an aqueous medium in the presence of at least 5% by weight of sodium chloride.
2.
A process according to claim 1 wherein said heat-treatment is performed under thermostable pH conditions for the microbial rennet.
3.
The process of claim 1 wherein the amount of sodium chloride is about 10 to 30 percent by weight.
4.
The process of claim 1 wherein the heat treatment is performed at a temperature of from about 50.
degree.
to about 80.
degree.
C.




Description:
This invention relates to a process for improving the quality of microbial rennet, and more specifically, to a process for improving the quality of microbial rennet by inactivating cellulase impurities in microbial rennet which comprises heat-treating microbial rennet in an aqueous medium in the presence of sodium chloride.
In the generally practiced art of cheesemaking, milk is clotted or coagulated by the enzymatic action of milk-clotting enzyme, to form a curd, the curd is cut into multiple pieces, and the pieces of curd are cooked to separate the liquid whey.
The collected curd is then enveloped in a cheese cloth or a cheese bandage and pressed for several days.
The green cheese so obtained is cured in a fermentation chamber for several months to form the desired cheese product.
The enzyme usually employed in the art to produce the curd by clotting or coagulation of milk is the enzyme rennin found in calf rennet which is obtained by the extraction of the mucosa of the fourth stomach of unweaned calves.
With an increased output of cheese production in recent years, the relative shortage of calf rennet supply has prompted many attempts to develop a suitable substitute for calf rennet.
A variety of microbial enzymes have emerged from these studies, and some of them are commercially utilized in the production of cheese