Optimization of milling degree for maximizing nutrient retention and yield in milled rice: A study on six common Bangladeshi rice cultivars
Md. Humaun Kabir, Md. Nahidul Islam, Md. Abdul Wazed, Minhaz Uddin Ahmed, Md. Sazzat Hossain Sarker
Abstract
Awareness of the nutritional value and health benefits of milled rice is crucial for its role as a staple food. This study explores the impact of different degrees of milling (DOM)—5%, 7%, and 9%—on head rice yield, proximate composition (protein, fat, fiber, and carbohydrates), and mineral content (sodium, magnesium, potassium, iron, calcium) in six rice cultivars: BRRI Dhan 28, 29, 36, 90, 51, and Bogura Katari. Our findings reveal that head rice yield decreases significantly, by 3% to 8%, when DOM is increased from 5% to 7% or 9%. Increasing the DOM also led to pronounced losses of protein (15% to 25%), fat (40% to 70%), and fiber (15% to 40%), while carbohydrate content increased. Additionally, substantial reductions in mineral content were observed at 9% DOM. Notably, consuming rice milled at 5% DOM can meet significant portions of daily nutrient requirements: 50% of protein, 10% of fiber, 20% of fat, 10% of sodium, 80% of magnesium, 35% of potassium, 100% of iron, and 30% of calcium, based on a per capita consumption of 400g per day. This research highlights the importance of optimizing DOM between 5% and 7% to enhance head rice yield and maximize nutrient retention.