Brown rice and white rice have similar amounts of calories, carbohydrates, and protein. The main differences between the two forms of rice lie in processing and nutritional content.

When only the outermost layer of a grain of rice (the husk) is removed, brown rice is produced. To produce white rice, the next layers underneath the husk (the bran layer and the germ) are removed, leaving mostly the starchy endosperm.

Several vitamins and dietary minerals are lost in this removal and the subsequent polishing process. A part of these missing nutrients, such as Vitamin B1, Vitamin B3, and iron are sometimes added back into the white rice making it "enriched", as food suppliers in the US are required to do by the Food and Drug Administration (FDA).

One mineral not added back into white rice is magnesium; one cup (195 grams) of cooked long grain brown rice contains 84 mg of magnesium while one cup of white rice contains 19 mg.

When the bran layer is removed to make white rice, the oil in the bran is also removed. Rice bran oil may help lower LDL cholesterol.

Among other key sources of nutrition lost are small amounts of fatty acids and fiber.

In addition to having greater nutritional value, brown rice is also said to be less constipating than white rice.

Brown rice can remain in storage for 6 months under normal conditions, but hermetic storage and freezing can significantly extend its lifetime. Freezing, even periodically, can also help control infestations of Indian meal moths.

 

Parboiled rice is rice that has been boiled in the husk. Parboiling makes rice easier to process by hand, improves its nutritional profile, and changes its texture.

Polishing rice by hand, that is, removing the bran layer, is easier if the rice has been parboiled. It is, however, somewhat more difficult to process mechanically. The bran of parboiled rice is somewhat oily, and tends to clog machinery. Most parboiled rice is milled in the same way as white rice.

Parboiling rice drives nutrients, especially thiamine, from the bran into the grain, so that parboiled white rice is 80% nutritionally similar to brown rice. Because of this, parboiling was adopted by North American rice growers in the early 20th century.

The starches in parboiled rice become gelatinized, making it harder and glassier than other rice. Parboiled rice takes more time to cook, and the cooked rice is firmer and less sticky. In North America, parboiled rice is generally partially or fully precooked by the processor.

Parboiling is a hydrothermal treatment of paddy. Parboiled rice is "par"-tially "boiled" (i.e. partially cooked rice). In other words parboiling means precooking of rice within the husk. Paddy is first hydrated, then heated to cook the rice and finally dried.

Parboiling Method
1. Raw rice (paddy)
2. The vitamins and minerals in the bran.
3. In a vacuum the rice loses all the air contained in it. In the following warm water bath the nutrients start to become soluble and move out of the bran.
4. To move the nutrients out of the bran, but inside of the rice, the hot steam and air pressure is used (otherwise the nutrients would just get washed out into the water).
5. In the end of the process the parboiled rice contains 80% of the nutrients of brown rice.

 

Tag:

Previous:  Destoner Application
Next:  Farm Tractors FAQ