Abstract
Three Chinese vegetables; Taasai, Tingensai and stem of garlic, were either boiled, boiled with salt, pan-fried or microwave-heated. Then the level of content for nine minerals in both the raw and the cooked vegetables were determined by atomic absorption spectrophotometry.
When we examined the raw Taasai and Tingensai, the mineral contents of Mn, Zn, Cu and Fe in the leaves were 2.5-8.4 times greater than those in the stems. In the case of cooked Taasai, the loss of K in the leaves boiled and boiled with salt and the loss of Fe in stems boiled with salt were quite larger, with the residual rate of 33-47% compared to the raw sample. The mineral P showed the greatest loss among cooked Tingensai, with the residual rate of 55% for the pan-fried leaves. The mineral contents in a stem of garlic did not change remarkably after cooking, and each residual rate was more than 67%.
The loss of minerals in three Chinese vegetables with various cooking methods was smaller when compared with the reported data of other vegetables.
