Rice as food

Lore & Background

Rice varieties are classified as long-, medium-, or short-grained, with differences in starch composition affecting texture. Long-grain rice is high in amylose and tends to remain intact after cooking; some long-grain varieties high in amylopectin, known as Thai Sticky rice, are usually steamed. Medium-grain rice is used for sweet dishes, risotto in Italy, and many rice dishes in Spain. Short-grain rice is stickier and holds its shape when cooked, used extensively in Japan for sushi and savoury dishes, and often for rice pudding. Rice can also be differentiated by aroma and pigmentation, such as red and black varieties. Wild rice, close cousins of domesticated rice, is not usually included in this classification.

Processing affects rice characteristics. Removing the hull by milling produces brown rice; polishing produces white rice. Cooking white rice then drying produces instant rice, though with significant degradation in taste and texture. Parboiled rice is first part-cooked with the husk before milling. Rice flour and starch are often used in batters and breadings to increase crispiness. The two main components determining taste are starch (80-90% of uncooked weight) and protein (7-10%). The ratio of amylose to amylopectin affects texture; higher amylopectin leads to stickier cooked rice. Protein content, influenced by fertilizer and growing conditions, increases surface hardness of grains.

Rinsing rice before cooking removes starch, yielding fluffier rice, but can cause loss of nutrients in fortified rice. Soaking reduces cooking time and stickiness; brown rice may be soaked in warm water for 20 hours to stimulate germination, producing germinated brown rice (GBR) with enhanced amino acids. Rice is cooked by boiling or steaming, with methods including absorption and rapid-boil. Electric rice cookers simplify the process. Rice is sometimes fried in oil before boiling, as in pilaf or biryani. In Arab cuisine, rice is used in soups, dishes with fish and poultry, stuffed vegetables, and desserts. Rice porridge (congee) is commonly eaten as breakfast and traditional food for the sick.

Reader's Guide

Rice is a foundational food for more than half the global population, serving as the primary dietary energy source for numerous countries across Asia, the Americas, and Africa. Its significance extends beyond mere sustenance; rice provides 20% of the world's dietary energy supply, a share greater than that of wheat or maize. The nutritional value of rice varies considerably based on type, strain, soil quality, processing, enrichment, and preparation. A 100-gram serving of cooked unenriched long-grain white rice provides 130 kcal, with moderate amounts of manganese. Fortification of rice with iron is recommended by the World Health Organization as a public health strategy to improve iron status in populations where rice is a staple, reducing the risk of iron deficiency by 35% and increasing hemoglobin levels.

Hazards associated with rice consumption include arsenic from the soil and Bacillus cereus food poisoning from poorly stored cooked rice. The FDA monitors arsenic levels in rice products, particularly infant foods, and has proposed a limit of 100 ppb for inorganic arsenic in infant rice cereal. Arsenic is a Group 1 carcinogen, with concentrations varying widely; brown rice and rice grown on land formerly used for cotton in certain US states show the greatest concentrations. Rice grown under elevated carbon dioxide levels, as predicted for the future, has been found to have reduced iron, zinc, protein, and several B vitamins. The versatility of rice in cuisines worldwide—from sushi to risotto, from congee to biryani—underscores its enduring role as a global dietary staple.

Did You Know?

• Rice provides 20% of the world's dietary energy supply, more than wheat (19%) or maize (5%).
• A 2018 WHO guideline recommends fortifying rice with iron as a public health strategy to reduce iron deficiency by 35%.
• Rinsing US-produced fortified rice before cooking can strip away added vitamins and minerals, as seen in a 2007 beriberi epidemic in Haitian jails.
• Rice grown under elevated carbon dioxide levels, similar to those predicted for 2100, had less iron, zinc, protein, and several B vitamins.