Abstract
At present, the methods of stabilization of chlorophyll in green leaves during their heating are still not completely established. In this work we studied the difference of heat stability of chlorophyll in spinach and persimmon leaves under various conditions.
The results obtained were as follows:
1) The extent of heat decomposition of chlorophyll in persimmon leaves (cutted leaves) was much greater than that in spinach leaves (cutted leaves) when they were heated in distilled water.
2) This phenomenon was also appeared when they were heated in buffer of the neutral or weak alkali area.
3) Chlorophyll in the powdered persimmon leaves, which were prepared from lyophilized leaves, was remarkably stable for heating as compared with them in the whole or cutted leaves. This may be that the increase of surface area on leaves facilitates the elution of substances such as acids which contained in persimmon leaves and have effect for chlorophyll.
4) When the chloroplasts prepared from spinach and persimmon leaves were heated in the various pH buffers, the heat decomposition of chlorophyll was similar to each other. That is, chlorophyll in both chloroplasts was rapidly decomposed at acidic area but was stable at neutral and weak alkali area.
5) The heat decomposition of chlorophyll depended on concentration of tannic acid, but reduced ascorbic acid had little effect.
