Saving Grain and Reducing Loss | Where Do Losses Typically Occur in Rice Processing?

Rice grains consist of the husk, pericarp, embryo, and endosperm. The main processing steps for paddy rice are cleaning, hulling, and milling. Paddy cleaning is carried out to remove impurities such as sand, gravel, metal fragments, and weed seeds; hulling involves removing the outer husk to produce brown rice; and milling entails stripping away the bran layer from brown rice to produce milled rice with superior eating quality.

The average milled-rice yield in China’s rice-processing industry is approximately 65.5%, with an average of 63.3% in the main indica-rice-producing regions and 66.7% in the main japonica-rice-producing regions of Northeast China.

The main losses in rice processing are broken rice and rice bran. During paddy milling, the husk—accounting for 16% to 20% of the paddy weight—and the brown-rice bran—accounting for 5% to 7%—are removed. Notably, the germ and aleurone layer contain nearly 64% of the rice’s nutrients and more than 90% of the micronutrients required by the human body. The higher the degree of milling, the greater the loss of nutritional value; in brown rice, the levels of calcium, iron, niacin, vitamin B, and vitamin E are 1.7 times, 2.7 times, 3.2 times, 10 times, and 14 times those in white rice, respectively.

By applying appropriate processing technologies, the milled-rice yield can be increased by 3% to 5%. Based on China’s 2021 processing volume of 212 million tonnes of edible paddy rice, this could translate into an additional 6.4 million to 10 million tonnes of milled rice. Assuming an average yield of 470 kilograms per mu, this would be equivalent to increasing paddy rice production by approximately 13 million to 22 million mu of cultivated land.

Developing moderate-processing technologies for paddy rice enables consumers to enjoy nutrient-rich rice that retains its nutritional value across all three daily meals, thereby promoting health in a convenient and cost-effective manner. For processing enterprises, moderate processing increases the milled-rice yield, reduces energy consumption during production, and enhances economic efficiency.

Moderate processing technology is undoubtedly a concrete manifestation of the “storing grain in technology” strategy, helping to develop the intangible “grain field,” safeguarding food security, and promoting the development of China’s greater health industry.