For many people in Asia, the consumption of white rice led to vitamin deficiency and, as a result, to “beriberi disease”. This causes damage to the nervous and circulatory systems. To combat beriberi disease, a special process was developed to preserve vitamins and minerals in white rice: the parboiled process.In the original, traditional parboiled process, the raw rice is steamed, then dried in the sun and then sanded and polished in the traditional way. In the 1940s, the USA developed a hydrothermal process based on steam and vacuum pressure : the rice grains are immersed in hot water to release vitamins and minerals from the individual layers. A pressure treatment then takes place in three different work steps: The dissolved vitamins and minerals are pressed into the interior of the grains using high pressure and then “sealed” under steam pressure . At the end, a large part of the liquid is removed from the grains using negative pressure.
White rice is much more popular than brown rice because white rice was originally considered a status symbol for the wealthy - similar to white flour in Europe. But what is the difference between white and brown rice? The rice grain consists of several layers - similar to an onion . The most important ingredients are contained in a layer, the so-called silver skin. The silver skin gives the brown rice its reddish brown color . Important ingredients are also found in the germ (kernel) of the rice grain, which is located below the inner grain, which consists largely of starch. During the production of white rice, the silver skin, protein-rich layers and the nutrient-rich seedling are ground away . Important components, such as: B. digestive fiber, proteins, polyunsaturated fatty acids and a number of vitamins and minerals are lost. These substances are still present in brown, red or black brown rice - which is why brown rice is healthier than white, milled rice.
Grinding and polishing of rice is carried out in the testing laboratory to determine the quality of a rice delivery.
The rice is filled directly from the rice silos (top left and right) into the container with warm water (bottom).After going through this process, the parboiled rice can be further processed and milled in the rice mill in the same way as normal brown rice. The milled parboiled rice contains up to 80% of the vitamins and minerals found in brown rice . It is translucent and has a slightly yellowish color because when the grain is steamed, color pigments from the silver skin are also transported into the interior of the grain. The parboiled process leads to a change in the cooking properties of the respective type of rice - so parboiled rice usually has to be cooked for a shorter time. The steam treatment hardens the surface of the grain - a kind of “sealing” occurs. For this reason, parboiled rice remains grainy and fluffy - hence the well-known advertising slogan “The rice that never sticks”.
One of the largest producers of parboiled rice in Italy: Riso Viazzo!Today, about a fifth of the world's rice harvest is processed into parboiled rice . A major disadvantage of the process is that the rice loses its aroma. For this reason, consuming “parboiled basmati or jasmine rice” is not recommended. The smell typical of these fragrant rice varieties is certainly lost during parboiling.
For further information, here is another literature tip: The Big Book of Rice. History, cultivation, varieties, kitchen practices and recipes. By Dr. Klaus Lamp, Eckart Witzigmann, Tony Khoo and Christian Teubner. (Series: Teubner Edition)