Parboiling Process
The rice grains are made of husks, film, germ and wrapped in vitamins and minerals salt that are concentrated in the film and in the germ. The endosperm contains mainly starch.
The word parboiled derives from an English expression parboiled, partial idea of cooking is going on in the industrial process.
The Parboiling process is based on submerged hydrothermal treatment of rice, only by the action of water and no chemical agent.
The parboiling is done through three basic operations:
Ponding
The rice husk is placed on tanks with hot water for several hours. In this process the vitamins and minerals found in the film and the germ can penetrate the grain as it absorbs water.
Gelatinization
The wet rice is subjected to a higher temperature on vapor pressure, a change occurring in the structure of starch. At this stage, the grain becomes more compact and vitamins and minerals are set in it.
Drying
In this stage, the rice grains are dried for its later hulling, polishing and selection.