De hydrolyse van vet bij de kaasrijping in verband met de smaak van kaas

Fatty acids are important as constituents of cheese flavour. In cheese made from raw milk, milk lipase probably hydrolyses cheese fat to some extent, but cheese made from aseptically drawn milk shows no piquant flavour.
It was established that during ripening no active lipase was formed inside the cheese. Enzymes of isolated strains of Lactobacillus and Micrococcus, genera normally found in ripened cheese, failed to hydrolyse fat to a measurable extent in normal conditions for hard cheese. Bacteria from the genera Pseudomonas Achromobacter, Alcaligenes and Serratia, belonging to the normal flora of milk, caused considerable fat hydrolysis in cheese, although these bacteria did not grow in cheese, and died within a few days. Micro-organisms growing on the surface of hard cheese could hydrolyse the fat of the cheese rind.

As the fat-splitting bacteria are killed by pasteurization of the milk, cheese from pasteurized milk shows no piquant flavour. Addition of suitable amounts of cultures of fat-hydrolysing bacteria to pasteurized milk improved the cheese flavour. The acidity of cheese fat was a useful estimate for the lower free fatty acids as they constituted a standard proportion of total fatty acids.