When people eat grapes, they often eat seedless white grapes with their skins. When they eat other grapes, they have to spit out the skins because they are astringent. But from a nutritional point of view, don't spit the skin when eating grapes.
Grape skin is rich in resveratrol, a polyhydroxyphenol compound, which has the functions of reducing blood lipid, antithrombotic, preventing arteriosclerosis and enhancing immunity.
Tannin, another important substance in grape skin, has the functions of antiallergic, delaying aging, enhancing immunity and preventing cardiovascular and cerebrovascular diseases.
Anthocyanins contained in grape skin have strong anti-oxidation, anti-mutation, relieving liver dysfunction and protecting cardiovascular system.
Grape skin also has anti-cancer effect. Researchers at Illinois Pharmaceutical University found that this substance exists in more than 70 kinds of plants such as peanuts and grapes, especially grape skins and red wine.
Because most of the grapes on the market now have pesticide residues, they must be cleaned before eating them with skins. It is best to rinse with clean water first, and use cleaning products that can effectively remove pesticide components, and clean for more than two minutes. However, it is not suitable to soak in water or salt water, because water soaking is easy to promote the penetration of pesticide residues on the surface of grapes into the pulp.