“China’s rice industry is undergoing a transformation from quantity-driven to quality-driven &quantity-based. Rice was regarded solely as the energy provider for humans for thousands of years. As the staple food, rice should also carry out the mission of improving the nutrition and health conditions of human beings. Therefore, we began to conduct research on whole grains such as black rice,” said Zhang Qifa, academician of the Chinese Academy of Sciences and professor of Huazhong Agricultural University at the 2023 First International Forum on Modern Agriculture held by the Tongxiang Municipal People’s Government and Wiley Publishing Group on April 21-23.
Zhang Qifa gives a speech at the first International Forum on Modern Agriculture in 2023. (live screenshot)
“If you can understand this picture, you won’t eat refined rice or flour any more!” Zhang employed a diagram of anatomical structure of grains to explicate the whole grains. The cellular structure of a rice grain from the outside to the inside are the pericarp, seed coat, aleurone layer, germ, and endosperm (all are included in whole grains). Nutrients diminish greatly in refined rice: if the husk and seed coat are removed, the plant pigments, phenolic acids, dietary fiber, and minerals will be lost; if the aleurone layer removed, the grain will lose its proteins, vitamins, minerals, and unsaturated fatty acids; if the embryo removed, the grain will lose polysaccharides and other bioactive substances. In the end, only the endosperm is left, which mainly consists of starch and a small amount of protein. This is the white rice and flour that we eat every day. Approximately 80% of the nutrients are lost during the processing, and more than 25% of the biomass is also removed.
According to Zhang, whole grain rice must be consumed to maximize the nutrients and health benefits of rice. Taking black rice as an example, it is not white rice plus anthocyanins, because its aleurone layer, germ, pericarp and seed coat can all provide nutrients.
On November 24th, 2022, Zhang Qifa gave a report. photo/ Liu Tao
In the view of Academician Zhang, a quickly-digested, high-carbohydrate diet, such as milled rice and wheat, is a major contributor to insulin resistance, which is a root cause of sub-health conditions and major diseases, such as hyperglycaemia (which further leads to diabetes), hypertension, hyperlipidemia, and inflammatory reactions. On the other hand, whole grains contain lower energy but are rich in dietary fibre, protein, fat, B vitamins, vitamin E, calcium, iron, zinc, and other minerals. They also contain a large number of secondary metabolites such as flavonoids and polyphenols, which can bring multiple health benefits such as lowering blood sugar/lipids, promoting intestinal motility, and improving antioxidant capacity.
Black rice is plain in taste, rough in texture, and hard to digest. People generally take it as a kind of coarse cereals. Prof Zhang and his team have spent over a decade doing research on black rice, seeking to develop a delicious, easy-to-cook and healthy variety. They collected varieties from all over the country and conducted genetic improvement. In 2018, they finally developed a new variety of black rice which was rich in taste and nutrition, naming it “Huamoxiang”. Ever since then, a new concept of “rice-type whole-grain black rice” was proposed by them, and the relevant industry standards were formulated later. Preliminary studies showed that black rice had a lower glycemic load than white rice and steamed buns and could also increase the production of antibodies in response to the COVID-19 vaccine, which indicated a promising health benefits.
Zhang proposed three prospects for the future development of black rice and whole grains: First, it is essential that experts in the field of rice biology continue to work hard to explore and utilize genetic resources, clarify the biological basis, and use genomic breeding technology to develop better varieties; Second, it is important to establish an evaluation system of nutritional values and conduct large-scale health evaluation research ranging from animals, models, cells to humans; Third, it’s necessary to promote the development of relevant industry so as to develop efficient production models, establish brands and explore the market.
“We advocate to make black rice staple food and develop more whole grains to be staple food. With the ongoing improvement of public health awareness and the deeper research into whole grains, I believe these initiatives will become a reality in the near future,”said Zhang.
Source：http://news.hzau.edu.cn/2023/0426/66318.shtml
Translated by Yu Xianqin
Proofread by Wang Xiaoyan
