A
diastase (; from
Greek διαστασις, "separation") is any one of a group of
enzymes which
catalyses the breakdown of
starch into
maltose. Alpha
amylase degrades starch to a mixture of the disaccharide maltose, the trisaccharide maltotriose, which contains three α (1-4)-linked glucose residues, and oligosaccharides known as dextrins that contain the α (1-6)-linked glucose branches. Diastase was the first enzyme discovered. It was extracted from
malt solution in 1833 by
Anselme Payen and Jean-François Persoz, chemists at a French sugar factory. The name "diastase" comes from the Greek word διάστασις (
diastasis) (a parting, a separation) because when beer
mash is heated, the enzyme causes the starch in the barley seed to transform quickly into soluble sugars and hence the husk to separate from the rest of the seed. Today, diastase means any α-, β-, or γ-
amylase (all of them
hydrolases) that can break down
carbohydrates.