There are three distinct manufacturing practices for yeast extract production:
autolysis, plasmolysis and hydrolysis. Autolysis is a process by which the cell
components within the cells are solubilized by activation of enzymes, which are
inherently present in the cell. This is achieved by carefully controlling temperature,
pH and time, with the careful addition of enzymes or reagents to stimulate
degradation and release of the cell contents into the medium. The amount of
free amino acid present in the extract can serve as a rough guide to indicate the
degree of hydrolysis . free amino acids are known to directly or indirectly exert
major influences on food flavour.