Many people think that the white frost on the grapes is the pesticide residue sprayed and will be poisoned if eaten. The '3 & middot; 15' Party showed professional results: the white frost on grapes is not pesticide. So what is the white frost on grapes? Is the white frost on grapes pesticide residues or natural substances?
The main ingredients of this kind of white cream are actually non-toxic and harmless natural wax, and a small amount of organic matter such as sugar. The real pesticide residues are trace substances, which are rarely visible to the naked eye. In addition to grapes, white frost on the surface of many fruits and vegetables, such as winter melon, plum and blueberry, is also the same substance.
When buying grapes, we often find a layer of white frost on the surface of the grapes. Many people are worried about whether this is something dirty.
In fact, this layer of white frost is the sugar and alcohol substances secreted by grape itself, which is called 'fruit powder'. Fruit powder is not only harmless to human body, but also shows that grapes are very fresh!
To some extent, white frost is a sign of grape freshness, but it can not avoid some merchants spraying low concentration of fungicides. The specific distinguishing method is that the normal 'white frost' is naturally and evenly distributed and does not cover the color of the grape skin itself, making the grape look more beautiful. But if it's the "white frost", the appearance distribution is uneven, and there will be dark blue traces.
The effect of white frost on grape skin the white frost on grape skin is not only harmless to people, but also has a great effect.
1. Adapt it to the arid environment
This layer of fruit powder has a protective effect on fruit. For example, this layer of fruit powder on the surface of grape can reduce water evaporation, thus preventing rapid water loss and shrinkage after picking, and has a positive effect on adapting to the dry environment.
2. Reduce the infection of pathogenic bacteria
The water-insoluble property of this layer of fruit powder can avoid the formation of a humid environment on the surface of grapes, thus reducing the infection of pathogens.
3. No additional yeast is needed for wine making
This layer of white cream on the surface of grape also contains yeast, so the self-made wine can be fermented without additional yeast.