3.5. Alcohol Industries

The raw materials used in the production of alcohol consists of mixtures of many different sugar-containing and starch-containing materials:

• In the presence of sugar-containing raw materials it is only needed the action of the fermentation agents (yeasts).
• When starch (from maize, potatoes, barley, cassava, etc) is present, it must be hydrolysed to fermentable sugars with hydrolytic enzymes (amylases, amyloglucosidase, proteases). These enzymes carry out liquefaction and saccharification (the two stages of the enzymatic hydrolysis of starch). Only after this pretreatment the fermentation takes place.

The use of enzymes of vegetable origin (malt and koji) is expensive and this is why industrial enzymes have nearly totally replaced these enzyme sources. As a result the predictability of the process is improved and a product of consistent quality is obtained.