Amylase is an enzyme that breaks down starch, converting it into sugar. There are two major types: alpha and beta. Alpha-amylase is found in human saliva, where it begins a chemical process in digestion with the hydrolysis of starch. It is also found in the pancreas. Beta-amylase is found in the seeds of some plants, as well as bacteria, yeast, and molds. Amylase is also found in other animals that use it to aid the digestive process.
This enzyme begins its work in the mouth when food is chewed, breaking up the polysaccharide bonds that link together to make chains of starch molecules. Starch naturally contains glucose, which the body separates in order to deliver the right nutrients to the blood stream. By breaking up and separating the various bonds within starch, amylase can extract the sugar so that it can be stored in the body. This process begins in the mouth and proceeds to the pancreas, where more of the enzyme is used to break up carbohydrates and pass food through the gastrointestinal system. For individuals incapable of producing enough amylase to properly break down starch, medical supplements containing it can help compensate for the body's deficiency.
Medical professionals and labs can use amylase as a means of detecting pancreatic disorders through blood and urine tests. Varying levels of the enzyme in the blood stream can indicate whether a person is suffering from pancreas-related disorders, such as pancreatic cancer or gallbladder attacks. Levels in urine can also help detect problems with kidney function.
Beta-amylase separates maltose disaccharides, or malt sugar, from starch. Some vegetables and many fruits taste sweet in part because of the role that the enzyme plays to break starch down into sugar. This is one reason why sweet potatoes have their signature sugary taste.
Industrial processes, such as the brewing of beer, use beta-amylase. The enzyme, secreted from yeast, breaks up the maltose compounds in barley, turning it into malted barley, and thereby aiding the fermentation process. Its presence in yeast is also the reason why amylase often plays an important role in bread making, where it breaks down starch, adds flavor and leavens dough.
Other industries use amylase as well. The clothing industry uses the enzyme to soften starch in fabric, so denim jeans aren't stiff as a board. It also is used as a key ingredient in laundry fabric softener.