Does the white rice we eat every day really cause high blood sugar? What's the point of cooking?
In this issue, we invite Teacher Yang Yuexi from College of Food and Bioengineering, Zhejiang Gongshang University to explain rice and the science in rice.
A reasonable diet is more important than "lowering blood sugar"
So, for healthy people, does rice really cause hyperglycemia?
Teacher Yang believes that this is a misunderstanding.
Moreover, because the process of human digestion is not instantaneous, it takes some time for starch in rice to be digested into glucose or oligosaccharides. The rice consumed every day will not be fully digested and absorbed in the intestine. According to the data obtained from in vitro simulated digestion experiments, only about 60%~70% of starch will be converted into glucose and absorbed by human body. Eating vegetables and meat with rice at the same time will affect the digestion of rice, which will reduce its digestion speed and degree most of the time. Therefore, there is no need to worry too much about the hyperglycemia caused by eating rice. In fact, a reasonable diet is more important.
In addition, the varieties and cooking methods of rice will also have an impact on the digestion of rice. Its action mechanism is related to the water-absorbing gelatinization and aging degree of starch molecules.
For example, porridge is digested faster than dry rice, and fresh rice is digested faster than overnight rice.
For the recently popular "hypoglycemic rice cooker" on the e-commerce platform, Teacher Yang said frankly that her family also bought this kind of rice cooker because of false propaganda. "I advised her not to open it." Teacher Yang said, "The rice soup filtered by the hypoglycemic rice cooker contains a lot of water-soluble nutrients such as vitamins (especially B microorganisms), minerals and protein peptides. Most of the rice cooked by this rice cooker is starch. "
Why are rice balls and rice cakes resistant to hunger?
It is related to the digestion of starch.
Enzymes that can digest starch in human body come from pancreas and salivary glands and are mixed amylases, among which α -amylase is the most familiar.
At present, some weight-loss and sugar-control products have α -amylase blockers, most of which are extracted from white kidney beans, commonly known as "kidney beans". Therefore, white kidney bean extract is a very popular food ingredient in the field of weight loss. But can soy lose weight? Even if they can, they are talents with a certain molecular structure under certain extraction conditions. When the bean element has gone through the cooking process of roasting, grinding, boiling and frying, and then mixed with a bunch of other ingredients, whether it has the function of losing weight remains to be considered.
The release of enzyme water depends on the molecular structure and the degree of molecular crowding. The reason why the foods we eat, such as eight-treasure rice, black rice balls and green rice balls, are difficult to digest has little to do with which enzyme. Because of its high viscosity and insufficient chewing, it is a viscous substance in the stomach, and the amount of decomposition by gastric acid and gastric peristalsis is limited. After the digestive enzyme solution enters the intestine, it is difficult to enter the inside of this viscous substance, and it can only work slowly from the outside.
So foods with high viscosity are difficult to digest. In the form of rice balls and rice cakes, it is difficult for enzymes to enter starch molecules with high viscosity and crowded inside, so glutinous rice products are not easy to hydrolyze.
So, after eating a bowl of freshly cooked indica rice or glutinous rice, which one feels hungry fast? -Indica rice is hungry fast, and glutinous rice is more resistant to hunger.
In addition, starch is also divided into "amylose" and "amylopectin". There are more sites where amylopectin can be acted by amylase, so the final digestibility is higher. Amylose is easy to age and crystallize, and the taste after crystallization is rough and the digestion is slow. But the aging of starch (that is, the recrystallization of starch molecules) takes time and low temperature. Therefore, eating cold indica rice overnight will slow down digestion! But the overnight meal taken out of the refrigerator was hard and crisp, and the entrance felt gritty. There are some hypoglycemic rice on the Internet, and many consumers spit like eating sand. These rustling substances are actually indigestible amylose polymers.
hobby group
Why does the rice cooker cook so well?
Rice, also known as rice, is one of the staple foods of our people. According to the variety type, it can be divided into indica rice, japonica rice and glutinous rice.
There are not only white rice, but also Redmi, green rice, black rice and purple rice.
According to different producing areas, the quality of rice has different characteristics. Since 2005, China has implemented the Regulations on the Protection of Geographical Indications. The geographical indications of rice entering the national standard are Wuchang, Panjin, Fangzheng and Yuanyang. For example, local standard rice includes Ding 'an Fushou and Songjiang.
According to different processing methods, rice can also be divided into brown rice, white rice/germ rice, steamed rice, broken rice and so on.
The edible rice we usually eat is white rice, but brown rice is basically endosperm after continuous processing and grinding off the cortex and germ.
The starch content in rice is the highest, followed by protein.
How do ordinary consumers identify the quality of rice?
High-quality rice has luster, neat particles, uniform particle size, and a dry feeling. There are few broken rice, immature rice, damaged rice, moldy rice and impurities in high-quality rice. Old rice is dark. Compared with new rice, the overall color is yellow and sour and sweet. The fragrance of rice weakens or disappears. After cooking, the viscosity decreases, and the rice grains are loose and basically have no fragrance. However, old rice can still be eaten as long as it is not moldy.
Using different cooking methods, different rice flavor substances can be detected, among which rice cookers detect the most flavor substances.
When cooking in a microwave oven, due to the high pressure of internal and external steam during heating, more volatile substances will overflow with the steam, thus reducing the types and contents of flavor substances in rice.
The aroma of high-pressure cooking is seriously lost in the depressurization stage, resulting in less flavor substances in rice.
The intelligent rice cooker has an automatic temperature control device, which can better control and master the temperature and heating time in the pot, so that the rice can fully emit fragrance and the aroma substances are not easy to lose.
Test you
A classmate ate a bowl of rice and drank a bowl of water on the first day; I ate two bowls of porridge for the second time, and the amount of water and rice was equal to the intake of the previous day. Which time is A hungry faster? (provided that the meal time is the same and the activity is the same)
Answer: porridge is hungry fast. Compared with dried rice, the starch molecules which are cooked thinly swell more completely with water, have a higher degree of degradation and are easier to digest.
How to eat rice without raising blood sugar?
A: When cooking, you can add a small amount of miscellaneous grains, such as millet, which is very popular in Northeast China.