What is the white frost on the grape skin

The nutritional value of grapes is very high. For the human body, it can enhance nutrition and prevent diseases. It has high content of vitamins and trace elements. Every time we buy grapes, there is always white frost on them. Many people don’t know what this is. In fact, the so-called white frost is a type of sugar alcohol secreted by grapes, which is harmless to the human body. The white frost is actually a sign that the grapes are fresh enough, so there is no need to worry.

The white frost on the grapes is a type of sugar alcohol secreted by the fruits and vegetables themselves, also known as fruit powder. They are natural substances synthesized by biosynthesis and are completely harmless to the human body. This type of compound is insoluble in water but soluble in organic solvents such as chloroform. Therefore, no matter whether it is soaked in water, washed or rubbed, this layer of white frost cannot be completely removed from the peel. It is said that flour can be used to wash off the hoarfrost. In fact, it does not really wash off the hoarfrost, but only changes the structure of the hoarfrost or blocks the gaps between the hoarfrost crystals.

The white frost on the grapes is harmless to the human body. This layer of fruit powder has a protective effect on the fruit. For example, the layer of fruit powder on the surface of grapes can reduce water evaporation, thereby preventing the fruit from losing water and shrinking quickly after picking, and plays a positive role in adapting to arid environments. The water-insoluble property of fruit powder can prevent the formation of a moist environment on the surface of the grapes, thereby reducing the infection of pathogenic bacteria. The white frost on the surface of grapes also contains yeast, so homemade wine does not need to add yeast during fermentation. It needs to be explained that grapes are a kind of fruit that is not easy to be infested with insects, and most of the current planting methods adopt the bagging method, so the chance of using high-concentration pesticides is very small. Therefore, if it is determined that it is the white frost on the grapes themselves, there is no need to wash it off.

To a certain extent, white frost is a sign of fresh grapes, but it cannot be avoided that some merchants spray low-concentration fungicides on the grapes. The specific method of distinction is that the normal "white frost" is distributed naturally and evenly and does not cover the color of the grape skin itself, making the grapes look more beautiful. If it is the medicine "white frost", the appearance will be unevenly distributed, and there will be traces of dark blue in it.

It is normal for grapes to have white frost. It is harmless and is just a substance secreted by grapes. In addition, buying grapes with white frost means that the grapes are very fresh. Another thing to note is that there is a method to washing grapes. When washing, do not separate them into grains and then wash them. Wash them in bunches. This can prevent water from entering the grapes after they are separated.