rice

Preparation as food

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The seeds of the rice plant are first milled using a rice huller to remove the chaff (the outer husks of the grain). At this point in the process, the product is called brown rice. The milling may be continued, removing the 'bran', i.e., the rest of the husk and the germ, thereby creating white rice. White rice, which keeps longer, lacks some important nutrients; in a limited diet which does not supplement the rice, brown rice helps to prevent the disease beriberi.

White rice may also be buffed with glucose or talc powder (often called polished rice, though this term may also refer to white rice in general), parboiled, or processed into flour. White rice may also be enriched by adding nutrients, especially those lost during the milling process. While the cheapest method of enriching involves adding a powdered blend of nutrients that will easily wash off (in the United States, rice which has been so treated requires a label warning against rinsing), more sophisticated methods apply nutrients directly to the grain, coating the grain with a water insoluble substance which is resistant to washing.

In some countries parboiled rice is popular. Parboiled rice is subjected to a steaming or parboiling process while still a brown rice. This causes nutrients from the outer husk, especially thiamine, to move into the grain itself. The parboil process causes a gelatinisation of the starch in the grains. The grains become less brittle, and the color of the milled grain changes from white to yellow. The rice is then dried, and can then be milled as usual or used as brown rice. Milled parboiled rice is nutritionally superior to standard milled rice. Parboiled rice has an additional benefit in that it does not stick to the pan during cooking, as happens when cooking regular white rice. This type of rice is eaten in parts of India and countries of West Africa are also accustomed to consuming parboiled rice.

Despite the hypothetical health risks of talc (such as stomach cancer),[5] talc-coated rice remains the norm in some countries due to its attractive shiny appearance, but it has been banned in some, and is no longer widely used in others (such as the United States). Even where talc is not used, glucose, starch, or other coatings may be used to improve the appearance of the grains.

Rice bran, called nuka in Japan, is a valuable commodity in Asia and is used for many daily needs. It is a moist, oily inner layer which is heated to produce oil. It is also used as a pickling bed in making rice bran pickles and Takuan.

Raw rice may be ground into flour for many uses, including making many kinds of beverages such as amazake, horchata, rice milk, and sake. Rice flour does not contain gluten and is suitable for people on a gluten-free diet. Rice may also be made into various types of noodles. Raw, wild, or brown rice may also be consumed by raw-foodist or fruitarians if soaked and sprouted (usually 1 week to 30 days); see also Gaba rice below.

Processed rice seeds must be boiled or steamed before eating. Cooked rice may be further fried in cooking oil or butter, or beaten in a tub to make mochi.

Rice is a good source of protein and a staple food in many parts of the world, but it is not a complete protein: it does not contain all of the essential amino acids in sufficient amounts for good health, and should be combined with other sources of protein, such as nuts, seeds, beans, fish, or meat.[6]

Rice, like other cereal grains, can be puffed (or popped). This process takes advantage of the grains' water content and typically involves heating grains in a special chamber. Further puffing is sometimes accomplished by processing pre-puffed pellets in a low-pressure chamber. The ideal gas law means that either lowering the local pressure or raising the water temperature results in an increase in volume prior to water evaporation, resulting in a puffy texture. Bulk raw rice density is about 0.9 g/cm³. It decreases to less than one-tenth that when puffed.

Cooking

There are many varieties of rice; for many purposes the main distinction is between long- and medium-grain rice. The grains of long-grain rice (high amylose) tend to remain intact after cooking; medium-grain rice (high amylopectin) becomes more sticky. Medium-grain rice is used for sweet dishes, for risotto in Italy and many arrossos — as in arròs negre, etc. — in Spain.

Rice is cooked by boiling or steaming, and absorbs water during cooking. It can be cooked in just as much water as it absorbs (the absorption method), or in a large quantity of water which is drained before serving (the rapid-boil method).[7] Electric rice cookers, popular in Asia and Latin America, simplify the process of cooking rice. Rice is often heated in oil before boiling, or oil is added to the water; this is thought to make the cooked rice less sticky.

In Arab cuisine rice is an ingredient of many soups and dishes with fish, poultry, and other types of meat. It is also used to stuff vegetables or is wrapped in grape leaves. When combined with milk, sugar and honey, it is used to make desserts. In some regions, such as Tabaristan, bread is made using rice flour. Medieval Islamic texts spoke of medical uses for the plant.[8]

Rice may also be made into rice porridge (also called congee, fawrclaab, okayu, jook, or rice gruel) by adding more water than usual, so that the cooked rice is saturated with water to the point that it becomes very soft, expanded, and fluffy. Rice porridge is commonly eaten as a breakfast food, and is also a traditional food for the sick.

Rice may be soaked prior to cooking, which saves fuel, decreases cooking time, minimizes exposure to high temperature and thus decreases the stickiness of the rice. For some varieties, soaking improves the texture of the cooked rice by increasing expansion of the grains.

Instant rice differs from parboiled rice in that it is milled, fully cooked and then dried. There is also a significant degradation in taste and texture.

A nutritionally superior method of preparing brown rice known as GABA Rice or GBR (Germinated Brown Rice)[9] may be used. This involves soaking washed brown rice for 20 h in warm water (38°C or 100°F) prior to cooking it. This process stimulates germination, which activates various enzymes in the rice. By this method, a result of research carried out for the United Nations International Year of Rice, it is possible to obtain a more complete amino acid profile, including GABA.

Cooked rice can contain Bacillus cereus spores, which produce an emetic toxin when left at http://www.nzfsa.govt.nz/consumers/food-safety-topics/foodborne-illnesses/safe-cooling-of-cooked-rice/index.htm. When storing cooked rice for use the next day, rapid cooling is advised to reduce the risk of toxin production.

Rice flour and starch often are used in batters and breadings to increase crispiness.

Synopsis of major staple foods

Synopsis[10] of Staple food ~composition: Amaranth[11] Wheat[12] White rice[13] Sweetcorn[14] Potato[15]
Component (per 100g portion) Amount Amount Amount Amount Amount
water (g) 11 11 12 76 82
energy (kJ) 1554 1506 1527 360 288
protein (g) 14 23 7 3 1.7
fat (g) 7 10 1 1 0.1
carbohydrates (g) 65 52 79 19 16
fiber (g) 7 13 1 3 2.4
sugars (g) 1.7 0.1 >0.1 3 1.2
iron (mg) 7.6 6.3 0.8 0.5 0.5
manganese (mg) 3.4 13.3 1.1 0.2 0.1
calcium (mg) 159 39 28 2 9
magnesium (mg) 248 239 25 37 21
phosphorus (mg) 557 842 115 89 62
potassium (mg) 508 892 115 270 407
zinc (mg) 2.9 12.3 1.1 0.5 0.3
panthothenic acid (mg) 1.5 0.1 1.0 0.7 0.3
vitB6 (mg) 0.6 1.3 0.2 0.1 0.2
folate (µg) 82 281 8 42 18
thiamin (mg) 0.1 1.9 0.1 0.2 0.1
riboflavin (mg) 0.2 0.5 >0.1 0.1 >0.1
niacin (mg) 0.9 6.8 1.6 1.8 1.1