Hello! According to relevant medical and agricultural data, the skin of walnut kernel is black, so don't eat it, so as not to be harmful to your health. The specific reason is that if chemical agents such as ethyl acetate are used to peel walnuts, even if the quality of nuts is not affected, toxic substances left on the shell of walnuts will inevitably be ingested when eating, so it will look like black and damage health. Suggestion: It is suggested that when buying walnuts, you should also choose walnuts with brighter skins, and don't buy walnuts with a gray-black appearance. I wish you good health