Cheese

Description of product

Cheese is a milk product. The milk is coagulated by the addition of rennet or lactobacilli, and salt, spices and cheese colourings are added to the thick milk curds. This is then left to mature at a specific temperature in cheese moulds. Worldwide there are about four thousand different types of cheese.

Distinguishing features:

• type of milk: cheese is mainly produced from cow milk. Some specialities are made from sheep, goat or buffalo milk.
• methods of coagulation: Most manufacturers add rennet, an enzyme produced by calf stomach, to coagulate the milk. Sweet milk cheeses, such as Gouda or camembert, are produced in this way. Curdled (sour) milk products, such as curd/quark cheese, Harzer cheese (a German speciality) or cottage cheese, can be produced by adding lactobacilli to coagulate the milk.

All ingredients including supplements have to be declared for packaged cheeses, with the exception of:

• milk components, enzymes and bacterial cultures required for production.
• see also: butter, milk,fruit yoghurt

Possible application of gene technology

Enzymes for cheese production:

• chymosin (the active ingredient of rennet): This protease causes milk to coagulate and is essential for cheese production. Traditionally chymosin produced by bovine stomach is used.
  Such compounds have received approval in nearly all Western and Eastern European countries including Germany. Therefore, it can be assumed that GM-chymosin is widely used. Cheese produced using this chymosin can be marketed without restriction and no particular declaration is required.
• the development of a particular flavour during the maturation of cheese can be regulated or intensified with the help of other enzymes (lipases, proteases, aminopeptidases). See also: flavourings
• the enzyme hexose oxidase can also be used to improve coagulation of the milk.

Applications of gene technology are possible in the following ingredients that commonly are found in cheese. However, the extent to which a particular product is affected by these possibilities cannot be stated with certainty:

• yellow colouring: lactoflavin (vitamin B2) or beta-carotene (E160 a)
• various preservatives have been approved for cheese throughout the EU: natamycin, nisin oder lysozyme is used to prevent an undesired gas production by the microorganisms. Previously, nitrate was mainly used for this purpose. Natamycin is used for external treatment of cheese, whereas Nisin and lysozyme are added during the production and remain in the final product.

Feed: the feed used in dairy farming can contain various raw materials and supplements for which gene technology can play a role.