1, the nutritional value is good. Because of the hard geological porcelain, high viscosity and hard soil, the shape of the black-bone yam is crooked and twisted, which is not very good-looking, but it is indeed the best of the iron yam, which has high nutritional value for strengthening the spleen, invigorating the stomach, restoring physical strength and lowering blood sugar. The taste of black-bone chicken vomit is not as good as that of the black-bone yam, and its nutritional value is slightly lower.

2. Good taste, firm and sticky soil, rich in mucus, high density of iron stick yam, less water and more powdery than common yam. It tastes better. You can see fine sticky silk when you break the yam. Rich in mucin, amylase, polyphenol oxidase and other substances.