In the season when the grapes were on the market, I watched the grapes in the fruit shop, and the saliva was DC. But what is the layer of hoarfrost on the grapes? It is very troublesome to clean. If you use a little force, it will poke the grapes. Does the white frost on the grapes hurt the human body? Need to be cleaned?
We often find a layer of hoarfrost on the surface of the grapes, and it is generally difficult to wash away with water. Many people are worried, what is this? Will it be something dirty? In fact, in addition to grapes, plum, blueberry, prunes and other fruits have similar hoarfrost on the surface.
In fact, this layer of hoarfrost is a sugar alcohol substance secreted by the grape itself, and its scientific name is fruit powder. Fruit powder is not only harmless to the human body, but also fruit powder indicates that the grapes are fresh!
To a certain extent, hoarfrost is a sign of fresh grapes, but it is also impossible to prevent some merchants from spraying low concentrations of bactericidal pesticides. The specific method of differentiation is that the normal “white frost” distribution is naturally uniform and does not cover the color of the grape skin itself, making the grapes look more beautiful. If it is a medicinal “white frost”, the appearance is unevenly distributed, and there will be dark blue marks.
The best way to clean the fruit is to rinse it with clean tap water, as many pesticides are readily soluble in water. The tap water contains about 0.2 ppm to 0.5 ppm of residual chlorine, which has the effect of sterilizing and oxidizing residual pesticides.