Rice milling refers to the process of removing the hulls and brans from the raw paddy grains and thus producing polished rice. Rice is a crop that is rich in genetic diversity, having a thousand of variants grown worldwide. It is one of the most consumed cereals worldwide. Today, this grain is helping 2/3 of the total world population to sustain. It is life for thousands of people and is also deeply engaged in the heritage of several countries and societies including south Asian countries. About four-fifths of the world’s rice is produced by the small-scale farmers and is consumed locally.
Milling refers to the process in which the grains are transformed in the suitable human consumption, and thus, it has to be done with utmost care to prevent the breaking of kernels and improving recovery. Rice grains also called as grains, consist of brown rice and husk. Brown rice, in turn, consists of bran comprising the outer layer and the edible portion.
The extent of the recovery during the milling process is dependent on several factors like the degree of milling required, a variety of paddy, quality of equipment used, the operator, etc. As and when the countries reach the self-sufficiency state of rice production, the demand of the consumer to get a better quality of rice increases. The quality of rice is hard to define in terms as it rests on the intended user and consumer of the grains.
The grain quality is not only proportional to the variety of rice, but also in the environment of production of crop, harvesting, processing as well as milling system.
The last step in the modern milling process is removing the broken rice grains from the milled rice with the help of blender machines. The screen separators and the sifters are used to separate the small broken rice, also known as brewer rice from the complete and large broken. Sifting also removes germs and brand and are present in the milled rice, even after the process of polishing and whitening.
The large broken and whole grains are either bagged for the customer delivery or are further processed through the length graders. From millers catering to the high end or export market, the length graders and the blending stations are used. The length grading process separates the broken rice from the large broken. Further, the rice blender helps in mixing the head rice and broken in right proportion as per the specification of the grade standards. For example, the premium grade rice in some countries allows for 95% head rice and 5% broken.
In usual rice-growing countries, the milled rice is marketed in bags, and thus, bagging stations form an integral part of the modern rice mill. The size of the bags is dependent on the requirements of the customers or suggestions made by rice mill consultants. The larger rice mills catering to the supermarket, milled rice are packaged in plastic packs of 2, 5, 10 and 20kg, and packaging is fully mechanized.
Blending station: – The rice blending solutions allows the mixing of the head and broken rice in the right proportion, as per the specifications of the grading standards.