After Rice is planted and harvested, the raw harvested rice is known as “PADDY” . Before this paddy is milled into the white rice we eat, it undergoes some processes . These processes include parboiling, Drying and Milling.
PARBOILING First the Paddy is soaked in warm water 70C for 8hrs or more. Then the water is drained and paddy is cooked or steamed for 45 minutes to 1 hour. By this time the shell of the rice begins to open and the content can be seen. Most people use drums and firewood to carry out this process. There are more modern equipment for doing with firewood or electricity.
DRYING After the parboiling process , the paddy is dried in the sun or with a drying equipment for 8 hours or more to reduce the moisture content to 14% or %13, which is accurate for the milling.
MILLING This is the process that transforms the paddy into the white rice that we eat. In some cases, the paddy is cleaned and destoned, using pre-cleaners and Destoning Equipment. Then the paddy goes to the Huller which removes the Shell. Then brown rice is gotten at this state. The brown rice is then moved to the milling or polishing section where the brown back or bran is removed to get the white surface .
Most modern milling machines combine the hulling and polishing processes . To further improve the appearance and quality of the rice, extra polishing equipment and color sorting equipment is used .
In a standard rice milling process, the flow goes from Paddy precleaning & Destoning -> Paddy Separation -> Paddy Dehulling or Dehusking -> Paddy Separation- >Rice Polishing-> Rice Grading-> Rice Polishing-> Color Sorting and finally packaging.
It is important to ensure that the parboiling process is done well, and the paddy moisture content is between 14% and 13% before milling. This is to affect discoloration and breakage of rice.
A moisture content meter is used to measure the moisture content of the grain .
Source: Best royal agro