Amylase is an enzyme, a kind of protein found in all plants and animals. It turns carbohydrates into sugars needed for energy and growth. Amylase is almost always present in the green parts of plants, although grains and starchy plants yield its heaviest concentrations. Many of those plants can be grown in home gardens.
Alpha amylase turns carbohydrates into all forms of sugar except malt. Plants and animals produce alpha amylase. Humans have it in saliva and produce it in the pancreas. It can change carbohydrates into sugar in minutes. Beta amylase, found only in plants, yields maltose. Whether plants are eaten raw, cooked or preserved, they contain the enzymes necessary for them to be digested. The more carbohydrates you eat, the more amylase you consume.
Options for Vegetable Gardens
Some garden vegetables that contain amylase can be eaten raw. These plants include beets (Beta vulgaris), celery (Apium graveolens), cauliflower (Brassica oleracea), onions (Allium cepa) and turnips (Brassica rapa). Beets and celery are annuals that grow in U.S. Department of Agriculture plant hardiness zones 2 through 10. Cauliflower is a cool-season annual vegetable typically harvested in fall, but it can be harvested in winter in USDA zones 8 through 10. Onions are perennials in USDA zones 3 through 9, and turnips are biennials in USDA zones 3 through 9.
Varieties with the Most Amylase
All cereal grasses except barley (Hordeum vulgare distichon) contain heavy amounts of alpha amylase. They include corn (Zea mays), common oats (Avena sativa), common rice (Oryza sativa) and bread wheat (Triticum aestivum). Barley, corn, common oats and bread wheat are annual plants grown in temperate zones. Common rice is an annual associated with tropical climates but also grows in warm temperate climates.
The sweet potato (Ipomoea batatas), hardy in USDA zones 9 through 11, has a high level of beta amylase. About 5 percent of the protein of a sweet potato is beta amylase. Malted barley, which is used to make beer, also has a high amount of beta amylase.
Kinds with Amylase Inhibitors
Some food plants heavy in carbohydrates contain substances that inhibit the action of amylase. These inhibitors delay the conversion of carbohydrates into sugars. Amylase inhibitors -- including those in wheat flour for baked bread and those in cooked beans (Phaseolus vulgaris) -- survive heat. Besides wheat and beans, foods that contain amylase inhibitors include barley, corn, millet (Pennisetum glaucum), peanuts (Arachis hypogaea) and sorghum (Sorghum bicolor). Beans grow as perennials in USDA zones 9 through 11 and as annuals elsewhere. Millet grows in USDA zones 2b through 11. Peanuts are annuals that grow in USDA zones 7 through 10, and sorghum is an annual that grows in USDA zones 2 through 11.