Paddy in its raw form cannot be consumed by human beings. It needs to be suitably processed for obtaining rice. Rice milling is the process which helps in removal of hulls and barns from paddy grains to produce polished rice. Rice forms the basic primary processed product obtained from paddy and this is further processed for obtaining various secondary and tertiary products. The basic rice milling processes consist of:
1. Pre Cleaning: Removing all impurities and unfilled grains from paddy 2. De-stoning: Separating small stones from paddy
3. Parboiling (Optional): Helps in improving the nutritional quality by gelatinization of starch inside the rice grain. It improves the milling recovery percent during deshelling and polishing / whitening operation 4. Husking: Removing husk from paddy
5. Husk Aspiration: Separating the husk from brown rice/ unhusked paddy 6. Paddy Separation: Separating the unhusked paddy from brown rice 7. Whitening: Removing all or part of the bran layer and germ from brown rice 8. Polishing: Improving the appearance of milled rice by removing the remaining bran particles and by polishing the exterior of the milled kernel 9. Length Grading: Separating small and large brokens from head rice 10. Blending: Mixing head rice with predetermined amount of brokens, as required by the customer 11. Weighing and bagging: Preparing the milled rice for transport to the customer The flow diagram of the various unit operations are as follows: Status of Rice Milling Units in India:
Rice milling is the oldest and the largest agro processing industry of the country. At present it has a turn over of more than 25,500/- core per annum. It processes about 85 million tones of paddy per year and provides staple food grain and other valuable products required by over 60% of the population. Paddy grain is milled either in raw condition or after par-boiling, mostly by single hullers of which over 82,000 are...