Effect of Different Processing Methods on the Nutritional Value of Rice

Abstract

Rice, the mostly used cereal grain, is composed of three layers-husk, bran and endosperm, each contains various specific components. These layers can be lost or retained depending on the different processing methods used. The objective of the present study was to know the nutritional value of raw and parboiled Ranjit rice obtained by de-husking method using both modern milling and a traditional de-husking method by “Dhenki”. After preparing the rice flour, estimation of carbohydrate, protein, crude lipid, crude fiber, Minerals: Fe, Zn, Ca, vitamins thiamin and niacin were carried out for all the rice samples following standard methods. The milled rice grains showed greater losses in the fat, protein and fiber contents compared to the rice grains de-husked by Dhenki. On the other hand, the parboiling of the paddy prior to de-husking enhanced the nutritional quality of the rice compared to the un parboiled raw rice as parboiling - allows some nutrients like Iron and vitamins to transfer from the hull into the grain. Parboiled rice also showed less carbohydrate content compared to the raw rice. Further study with animal model revealed that parboiled rice de husked by Dhenki showed slow rate of digestion indicating it as a source of good carbohydrate.The findings may be useful in helping the people to choose the right processing methods for rice to obtain maximum yield in nutrition.