Rice is high in calories and is a high-glycemic food. Once rice is eaten and digested by the body, blood sugar levels tend to rise rapidly, so people with diabetes can only eat it in small amounts. Wang Chiang-sheng, a professor in the Department of Agronomy at National Chung Hsing University, saw the troubles faced by some groups and four years ago began developing low-glycemic rice varieties, hoping to find rice that people with diabetes and those trying to lose weight could all enjoy freely. At present, the research team has already identified several low-glycemic rice varieties. Based on mouse trial results, a conservative estimate is that the glycemic index situation after eating can be significantly improved. They expect to file a plant variety rights application early next year, and once approved, it can be grown commercially and mass-produced.

People with diabetes can also enjoy white rice properly

Sixty percent of the world's population uses rice as a staple food. The main component of rice grains is starch. After people eat rice, the grains are ultimately digested into glucose, becoming one of the sources of calories. However, the rice eaten in daily life is a high-glycemic food (GI>55), so people with diabetes and those trying to lose weight cannot enjoy it freely.

For people with diabetes, unstable blood sugar affects health. Is it possible to screen out rice that does not raise blood sugar rapidly from a large number of rice varieties? Wang Chiang-sheng said that developing low-glycemic rice is precisely to allow groups who cannot eat rice, such as people with diabetes, to enjoy the pleasure of eating rice.

Last year, the Council of Agriculture promoted the program for the internationalization and sustainable development of the agricultural bioeconomy industry, hoping to combine experts' research capabilities to advance healthy agriculture in response to issues such as population aging, excessively high medical costs and food safety. Therefore, Wang Chiang-sheng worked with Professor Liao Hui-fen of the Department of Biochemical Science and Technology and Graduate Institute at National Chiayi University and several other units on "Development of Low-Glycemic Rice Varieties," screening low-glycemic (low GI value) or high-resistance starch (RS) rice lines and developing "low-sugar healthy rice" varieties as rice varieties for people with diabetes and weight-loss consumers.

Improved from Tainung 67 Glycemic situation can be significantly reduced

In the global rice market, 80% of people eat indica rice. In Taiwan's early period, indica rice was also the main type eaten, but currently japonica rice is the main type consumed domestically. Wang Chiang-sheng said with a smile that they first wanted to make rice that meets the needs of domestic people, so they first screened rice meeting the requirements from the Tainung 67 mutant library he had established, and in the future they will develop low-glycemic rice varieties of indica rice as well.

The Tainung 67 mutant library Wang Chiang-sheng spoke of was exactly the result of his past research at the Agricultural Research Institute, and it contains more than 3,000 pure rice lines. He said with a bitter smile that this was a result piled up through blood and sweat, because rice is inherently a high-glycemic food, and screening low-glycemic rice is actually very difficult. It was only because there were so many pure rice lines that a lot of rice could be produced for analysis.

The research team screened more than 2,000 kinds of rice in total before finding a small number of low-glycemic rice types. Wang Chiang-sheng said the preliminary screening trials alone took 3 years. Through biochemical techniques, enzymes were used to simulate the digestion pattern after a person chews rice, such as gastric digestion and intestinal absorption, in order to measure the ability of starch to be broken down by enzymes. The part that cannot be broken down is resistant starch, and only high resistance makes a low-glycemic rice variety. Each type of rice underwent more than 3 experiments. Based on mouse trial results, a conservative estimate is that the glycemic situation after eating can be significantly reduced.

Even the number of chews is analyzed

The research team finally managed to screen out several low-glycemic rice types, but the key experiments were only just beginning. Wang Chiang-sheng said that rice with high resistant starch means the rice has relatively poor digestibility after entering the esophagus, tastes somewhat hard, and has worse flavor than ordinary rice. Therefore, palatability must be taken into account in the experiments, selecting varieties that everyone can accept; otherwise, even if low-glycemic rice is developed, it still has no commercial value if it tastes bad.

In addition to screening varieties and choosing taste, Wang Chiang-sheng stressed that even the number of chews must be analyzed in detail. "Chew the rice a few more times, and the situation is different." Because food digestion is related to the chewing situation in the human mouth, it was necessary to find an instrument that simulates mouth chewing and repeatedly analyze the number of chews before finally presenting the experimental results.

At present, the research team has already identified several low-glycemic rice varieties and completed related animal experiments, confirming that these lines have low-glycemic potential. The next step will be to begin human trials to observe blood sugar conditions after people eat them.

Variety rights application may be filed as early as this year No obstacles for farmers to grow it

Wang Chiang-sheng said that the low-glycemic rice varieties in this study took market acceptance into account, and of course farmers' growing conditions were also taken into account. Whether in soil, fertilization management or temperature, there is no difference from the current cultivation method for Tainung 67. The experiments did not specifically measure whether the low-glycemic rice has particularly outstanding resistance to pests and diseases, but based on growing experience in recent years, there is no particular difference.

"It is expected that the plant variety rights application for the low-glycemic rice can be filed this year, and if approved it can quickly go on the market," Wang Chiang-sheng said. At present, small-scale mass production is underway, and many farmers are interested in cooperating. However, because the variety rights have not yet been applied for and approved, cooperation with farmers is temporarily impossible. Still, the future business model has already been planned, starting with seedling management and contract farming to control the source of the variety and maintain good production quality for farmers.

Related information

To learn more about the details of this project's research and development results, please contact Mr. He at the Agricultural Technology Research Institute, telephone: 03-5185049, email: [email protected]