acidité du lait

Traductions

• anglais

  Auteur : Office québécois de la langue française, 1983

  Notes :

  The formation of acidity in the milk to be used for cheesemaking, known as ripening, is usually brought about by use of a starter. The acidity developed inhibits the growth of undesirable organisms and influences the rate of coagulation. The starter used depends upon the type of cheese being made.
  
  Fresh milk actually contains no acid; yet has a definite titratable acidity. This fact indicates that the chemical used in the acidity test combines with some of the susbtances in normal milk. Hence, the milk appears to contain acid when it is absolutely fresh. This reading, often referred to as "apparent acidity", should not be confused with the actual acidity which may be formed later in the milk by bacteria. The substances which give milk its apparent acidity are: (1) the phosphates and citrates (minerals), (2) the casein and albumin (proteins), (3) dissolved carbon dioxide. High-testing milk averages a slightly higher content of proteins and minerals than low-testing milk; for this reason the acidity reading of fresh milk varies from about 0.13 per cent for low-testing milk to 0.2 per cent for high-testing milk. It is evident, therefore, that a high natural acidity in milk is not objectionable. This natural acidity does not increase in milk and does not make milk taste sour. After milk has been drawn from the cow, certain types of bacteria known as "acid-formers" find their way into it. Under favorable conditions these bacteria act on milk sugar and change some of it to an acid called lactic acid. This is the acid which makes milk taste sour.

  Terme :

  1. acidity of milk