Rice Quality: Biochemical Composition, Eating Quality, and Cooking Quality

Rice (Oryza sativa L.) is the main food for the largest community in the world, and its demand is increasing day by day. It is a highly palatable energy-rich food as a result of its starch content. Among different parts of rice, rice bran consists of high protein and energy. Brown rice is the most nutritious and consists of different types of fat (monounsaturated, polyunsaturated, and saturated), carbohydrates, protein, fiber, vitamins, and minerals. Rice loses some nutrients during milling process. Rice quality is a general concept which covers many characteristics ranging from physical to biochemical and physiological properties of rice. The eating and cooking quality (ECQ) of the rice grain is one of the most serious factors in many rice-producing areas of the world. The ECQs are important determinants of cooked rice quality. The ECQs are composed of several physical and chemical characteristics of starch in the endosperm, viz., amylose content (AC), gel consistency (GC), viscosity, aroma, gelatinization temperature (GT), and texture of cooked rice. Aroma of cooked rice is the most important feature of high-quality rice. Fragrance of rice is a combination of more than 100 volatile compounds, and among those, one chemical, 2-acetyl-1-pyrroline (2AP), is considered as the main contributor. Choice of grain size, shape, aroma, and appearance of rice varies from one group of consumer to another.