But you should know that this standard does not apply to all foods. Among the soft drinks and candy snacks we often drink, there is an invisible bomb fructose syrup, whose sugar index is lower than that of white sugar, but its harm is greater than that of white sugar.
What is fructose corn syrup?
Although there is? Fruit Portuguese? Two words, but fructose corn syrup has nothing to do with grapes or any fruit! Its raw materials are corns, potatoes, sweet potatoes, rice and other starchy foods.
Starch in these foods will be converted into glucose by amylase and glucoamylase, and high fructose corn syrup will be produced after adding isomerase. So high fructose corn syrup is also called starch sugar.
Then if it's made of starch, why is it called it? Fructose syrup? ? Because? Fruit Portuguese? Actually, it is a biological concept, referring to fructose and glucose.
These two sugars are the most basic molecules of saccharides in nature, so they are also collectively referred to as monosaccharides, which are abundant in fruits and honey. The fructose syrup produced by starch contains both fructose and glucose molecules, so it is called fructose syrup.
According to the ratio of fructose to glucose, there are about three kinds of fructose syrup: F42 containing 42% fructose, F55 containing 55% fructose and F90 containing 90% fructose. F42 and F90 are commonly used to prepare F55.
F55 is widely used in food industry because of its best sweetness and taste, and is often seen in beverages, sweets, ice cream, bread, cakes and quick-frozen foods. The fructose syrup added to cola is F55.
High fructose syrup has a high sweetness because of its high proportion of fructose, but its GI value is not high because of the different metabolic modes of glucose and fructose.
All cells in the human body can metabolize glucose, which will quickly enter the blood after eating, quickly raise blood sugar and provide energy for the human body. But the main metabolic site of fructose is the liver, because there is no rate-limiting enzyme in the liver to limit the reaction speed, so basically, the liver can absorb as much fructose as you eat and store it as fat.
Therefore, glucose has the greatest influence on blood sugar, and the GI value is as high as 100, which will strongly stimulate insulin secretion. However, the GI value of fructose is only about 25, which has little effect on blood sugar.
Compared with sugar, the GI of high fructose corn syrup is much lower, because more than half of it is fructose. According to the different fructose content, the GI value of high fructose syrup is between 55 and 75, which seems to be better for health.
However, more and more medical studies have found that the reason of low GI value of high fructose corn syrup, that is, its special metabolic mode, is endangering people's health more and more seriously.