The reason why walnut skin is black;
Walnut has three skins, one is green husk, the other is shell, the other is seed coat of walnut kernel, and there is actually a split wood. Walnuts on the market, the shell you see should be the shell of the finished product. There are two possibilities for the shell to turn black:
The first one is that when the walnut is picked, the shell is wet, or the green husk is not cleaned, or the walnut is not properly baked, resulting in local humidity, which will leave a black block on the shell mountain, but the inside is white. ?
The second type is: because the inside is black, the outside is black, because the goods are old or wet, or there is mildew and other deterioration inside. Your condition belongs to the first kind, so you can eat it normally. And it can prove that the walnut you bought (at least this walnut) has not been bleached by sulfuric acid, hydrochloric acid, hydrogen peroxide and so on.
Extended data:
According to the quality of walnut kernel, it is divided into four grades: the first grade requires walnut kernel to be kernel, and the kernel color is light yellow or amber; The second-class product requires that the walnut kernel is a quarter kernel, and the kernel color is the same as that of the first-class product; The three goods are broken kernels, and the kernel color can be as deep as amber; Other minced meat is four-way goods. All goods should be packed separately and marked.
Walnut kernels are plump in appearance, yellow and white in color, clean and tender in meat, and large and complete in slices. This is the best quality, you must pay attention to buying walnuts!
People's Network-How to identify the quality of walnuts? You are optimistic about these details.