Review on Physical, Mechanical and Nutritional Properties of Brown Rice

Abstract

Rice (Oryza sativa L.) is a major staple crop worldwide, and its production, postharvest processing, and nutritional quality are critical for global food security. This review examined the current knowledge on rice cultivation, milling practices, and nutritional composition, highlighting the advantages of modern technologies over traditional methods. Traditional rice cultivation and milling were labour-intensive, time-consuming, and less efficient. In contrast, direct-seeded rice cultivation and improved milling systems significantly enhanced productivity, capacity utilization, and head rice recovery. Moisture content played a crucial role in determining the physical and mechanical properties of paddy, affecting grain rupture force, energy requirement, bulk density, and thousand-grain weight, which in turn influenced milling efficiency and grain quality. Comparative studies on rice cultivars from Ghana, India, and Egypt revealed no significant differences in key milling traits, suggesting that postharvest technologies could be widely applied across diverse varieties. Nutritionally, brown and red rice were superior to white rice, containing higher levels of protein, fat, dietary fibre, minerals, and antioxidant compounds. Red rice, in particular, exhibited greater starch yield and improved functional properties. The review emphasized that optimizing grain moisture during processing, adopting modern milling technologies, and promoting nutrient-rich rice varieties were essential strategies to enhance postharvest efficiency, minimize grain losses, and support sustainable rice production. These findings provide valuable insights for researchers, policymakers, and farmers aiming to improve rice quality, increase processing efficiency, and achieve sustainable cultivation practices that meet nutritional and economic goals.