ANCIENT, FORGOTTEN PLANT NOW 'GRAIN OF THE FUTURE'
By JANE E. BRODY
Published: October 16, 1984
SCIENTISTS have rediscovered an ancient, highly nutritious grain that once sustained the Aztecs but has lain in agricultural obscurity for nearly 500 years.
The grain, from a large and especially beautiful group of plants known collectively as amaranth, was all but obliterated by the Spanish conquerers who destroyed the Aztec empire in 1521.
Now, however, amaranth may become the first food crop to be developed rapidly for wide cultivation using modern techniques of field breeding, laboratory cultures and genetic engineering. Agricultural researchers are cautiously hailing this relic of antiquity as ''the grain of the future'' for its potential to provide protein, vitamins and minerals to people worldwide, including the United States.
Amaranth contains more protein than other common grain foods (the tiny seeds are 16 percent protein, as against 12 to 14 percent for wheat) and the quality of that protein - its ability to meet human protein needs - exceeds that of protein in soybeans and even milk. Unlike other grains, amaranth is rich in the essential amino acid lysine. When combined with corn, for example, which is deficient in lysine, a ''protein score'' of nearly 100 results, meaning all the protein in the two foods is usable by the body.
The excitement over amaranth's potential is evident throughout a report on this crop just released by the National Academy of Sciences. Still, scientists who prepared the report warned against viewing it as a ''miracle grain'' lest it fall prey, as other new grains have, to disappointment generated by overenthusiasm.
Even at this stage of development, amaranth is already being grown by about 20 American farmers and limited supplies of amaranth flour and seeds and foods made from them are being sold here. According to the academy report, ''Amaranth, Modern Prospects for an Ancient Crop,'' grain amaranth, which can be ground into flour or popped like corn, can be used to make breads and rolls, crackers and cookies, cereals, soups, porridge, pancakes, pilaf, snacks, breadings, fillings, dumplings and beverages.
Some species of amaranth are already being grown for their nutritious green leaves, which resemble spinach in flavor but outrank other leafy foods as a source of essential nutrients, especially protein, calcium and iron. Unlike true grain plants, which are narrow-leaved grasses, amaranth is a broad-leaved plant that can produce huge seed heads, with up to 500,000 seeds per plant.
In addition, the unusually small, crystal-shaped starch granules in grain amaranth might find a place in the cosmetic industry as a replacement for talc.
Grain amaranth was as important as corn and beans to the Aztecs, who believed that it gave them supernatural powers and used it in ceremonies involving human sacrifice. Some 20,000 tons of the seeds were delivered by Aztec farmers in annual tribute to their emperor, Montezuma.
In Aztec rituals, amaranth was mixed with human blood, formed into cakelike replicas of Aztec gods and fed to the faithful, a practice the Spanish regarded as barbaric and a mockery of Christian communion. Hernan Cortes put a stop to it by condemning to death anyone found growing or possessing amaranth.
But enough of the self-seeding and easily grown plants survived to keep the crop alive, and to this day a few small farmers in Mexico and Central and South America grow it. Alegria, a confection of the Aztecs made with popped amaranth and honey or molasses, is still popular in Mexico and Central America. Amaranth seeds also found their way to Asia, where the crop has made steady gains in the last hundred years, especially among Himalayan farmers. In India, where amaranth is known as rajgira (''king seed'') and ramdana (''seed sent by God''), the popped seeds are mixed with honey or syrup to make candy.
Amaranth is the latest in a series of ''promising plant resources heretofore unknown, neglected or overlooked'' that have been examined in the last 10 years by the science academy's Advisory Committee on Technological Innovation. A previous subject of this committee's investigations, the winged bean, is now being grown in more than 70 countries in the tropics and subtropics.
But according to Dr. Noel D. Vietmeyer, staff officer for the committee, whose work was financed by the William H. Donner Foundation, amaranth's potential ''looks even better than the winged bean,'' largely because it is agronomically adapted to a very wide range of growing conditions. Various types of amaranth thrive in environments ranging from the wet tropics to semiarid lands and from sea level to mountainsides 10,000 feet above. Existing types can tolerate very acid or highly alkaline soils, long equatorial days and short temperate ones, dry spells, heat and mild salty conditions.
Some 60 different species of the genus Amaranthus have been found growing in Asia, Africa and the Americas. Some are grown for food, others as ornamentals and still others grow wild like weeds. Through breeding experiments, desirable characteristics can be bred into varieties with good-tasting seeds to expand their agricultural versatility and to incorporate desirable traits.