people like sweetness, which is associated with sugar. Sucrose, glucose and maltose are familiar sugars. They are not only sweet in taste, but also substances that supply human energy. Honey contains fructose and glucose. Fructose is the sweetest sugar. The ratio of the sweetness of fructose, sucrose and glucose is 9: 5: 4 according to the experimental determination.

do all sugars have a sweet taste? No. For example, there is 4% lactose in milk, which is a sweet sugar. On the other hand, are all sweet things sugar? You can't say that either. For example, although ethylene glycol and glycerol are sweet, they are not sugar.

so, how should sugar be defined? Generally speaking, polyhydroxyaldehydes or polyhydroxyketones or organic compounds that can become one of the above two after hydrolysis are called sugars in chemistry, and this definition is not necessarily related to sweetness.

As a sweet substance, people often eat white sugar, brown sugar and rock sugar. The sugar-making method is not complicated. Squeeze the juice from sugarcane or beet, filter out impurities, then add a proper amount of lime water to the filtrate to neutralize the acid contained in it, then filter and remove the precipitation, introduce carbon dioxide into the filtrate to precipitate the lime water into calcium carbonate, and then filter repeatedly to obtain the filtrate, which is the aqueous solution of sucrose. When the sucrose aqueous solution is evaporated, concentrated and cooled under reduced pressure in a vacuum, a reddish-brown slightly sticky crystal is precipitated, which is brown sugar. To make white sugar, it is necessary to dissolve brown sugar in water, add appropriate amount of bone carbon or activated carbon, adsorb colored substances in brown sugar water, filter, heat, concentrate and cool the filtrate, and a white crystal-white sugar appears. White sugar is much purer than brown sugar, but it still contains some water. Then, the white sugar is heated to a proper temperature to remove the water, and a colorless and transparent massive crystal-rock sugar is obtained. It can be seen that the purity of rock sugar is the highest and the sweetest.

When it comes to sweet substances, people naturally think of saccharin. Saccharin is not the essence of sugar. It is not extracted from sugar, but made from black and smelly coal tar. Saccharin has no nutritional value. A small amount of saccharin is harmless to human body, but excessive consumption of saccharin is harmful to human body. Therefore, saccharin can be eaten, but it should not be used more.

Sucrose is a carbohydrate with the highest caloric value. Excessive intake will cause obesity, arteriosclerosis, hypertension, diabetes and dental caries.