Rice (Oryza sativa; Poaceae), applied both to the cereal grain and the plant that produces it, originated in Africa, India, and southeastern Asia. Its cultivation has been traced to India in ~3000 BC and to China in ~1000 BC. The dark brown-purplish black wild rice (Zizania aquatica) is a distant relative of the cultivated white or brown rice.

Rice is a staple for half of the world population. Rice is produced in China, India, Japan, Bangladesh, Indonesia, Thailand, Vietnam, Brazil, South Korea, the Philippines, and the United States. There are three major types of rice (long, medium and short kernelled) and more than 8,000 varieties of rice cultivated around the world. Indeed, the Indian basmati rice renowned for its distinct aroma and flavor has a global acceptance.

The cultivated rice plant is an annual grass normally grown in underwater paddies or marshland. Rice can thrive under water because oxygen is transported from leaves to its roots. Rice plant grows to ~4' tall, and has several long narrow leaves. The end of the leaf stalk bears the inflorescence (panicle) with green and yellow flowers that produce the edible fruit- rice grains.

In Asian countries rice cultivation is a labor-intensive task that calls for families to pool their labor and water resources. In a given area rice is usually planted on the same day emphasizing group interests and group harmony- giving rise to a number of regional rice planting ceremonies, rituals, folk music and dances in different parts of the world. In most Asian cultures women play an important role in rice production, processing and marketing; newlyweds are showered with rice as a symbol of life and fertility, so they will be blessed with many children, prosperity, and abundance.

Rice is processed by three ways- only the husk is removed (brown rice), the husk, bran and part of the germ are removed (white rice), or the paddy is soaked and boiled before processing (parboiled rice). Brown rice contains ~8% protein and thiamine, niacin, riboflavin, iron, and calcium. The white rice has lost ~75% of the minerals. Parboiled rice contains 2-4 times as much thiamine and niacin as the white raw rice because parboiling drives them from outer bran into center of the grain.

Rice is puffed or toasted and used as breakfast cereals. It is used as an alternative to potatoes in the West. In the East Asian countries it is not only a staple, but also used in other forms- as flour in cakes, pastries and noodles, and fermented to make beer and liquors. Other parts of rice plant are also used- straw for thatching roofs and making mats, garments, baskets, rope, and brooms; burnt roots as fertilizer for rice fields; oil from the bran for food and industrial uses; by-products of milling rice livestock feed; hulls for fuel, packing material, and fertilizer; rice starch is used in cosmetics and laundry products. Rice straw beds are used in the Philippines to grow mushrooms.

The Chinese believe that rice strengthens the spleen and a "weak stomach," increases appetite, and cures indigestion. In India, a decoction of rice is prescribed as a salve to counteract inflamed surface. Rice seeds are used in folk medicine for breast cancers, stomach indurations and warts (1); and reported to be an astringent, diuretic, stomachic, tonic, and vermifuge and used for abdominal ailments, burns, diarrhea, dysentery, dyspepsia, inflammations, nausea, psoriasis, skin ailments, sores and swellings (2).

Rice bran oil is a healthy vegetable oil in Asian countries (3-4). Phytonutrients from rice bran have shown promising disease-preventing and health-related benefits including cancers, hyperlipidemia, liver problems, hypercalciuria, kidney stones, and heart disease (5-6).

REFERENCES

1. Hartwell JL 1967-1971. Plants used against cancer. A survey. Lloydia 30-34.
2. Duke JA and Wain KK 1981. Medicinal plants of the world. A computer index with more than 85,000 entries. Food and Agricultural Organization, Rome.
3. Nicolosi RJ et al. 1994. Rice bran oil and its health benefits. Food Sci Technol 59:421-437.
4. Sugano M et al. 1999. Health benefits of rice bran oil. Anticancer Res. 19:3651-3657.
5. Jariwalla RJ 2001 Rice-bran products: phytonutrients with potential applications in preventive and clinical medicine. Drugs Exp Clin Res 27:17-26
6. Mori H et al. 2000. Chemopreventive effects of coffee bean and rice constituents on colorectal carcinogenesis. Biofactors 12:101-105.

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