調理操作による野菜中無機8元素含有量の変化

抄録

The contents of nutritionally important mineral elements in vegetables were determined. The samples used in the present paper were five vegetables such as egg-plant, rape (flower), chinese cabbage, cauliflower and broccoli. Raw and cooked vegetables were homogenized and extracted with 2% hydrochloric acid.
The contents of eight minerals such as Na, K, Ca, Mg, Cu, Mn, Fe, Zn in the extracts were determined by Atomic Absorption Spectrometry method. When the vegetables were cooked in boiling water, the contents of eight minerals remaining in the tissues decreased drastically for 2minutes and gradually thereafter.
The contents of eight minerals remained in the vegetables cooked by micro-wave irradiation were higher than those cooked in the boiling water. Minerals remaining in the lowest values in the tissue after boiling for 10 minutes were Na and K, and the remaining percent was from 14 to 19%in chinese cabbage, egg-plant and repe (flower).
The remaining amounts of the other trace elements after cooking were higher than those of the above major elements. Elements in egg-plant, rape (flower) and chinese cabbage were easily lost in the water during cooking process, on the other hand, those in cauliflower and broccli remained in the tissue. This difference among these vegetables may be due to the difference of the size, shape and area of the cutting surface of the samples used.