加熱方式對綠色蔬菜色素崩解的影響

Effect of Heating Pattern on Pigment Degradation of Green Vegetable Leaf

本文探討急速加熱和漸進加熱對三種綠色蔬菜的葉綠素、類胡蘿蔔素及葉綠素的三種前驅物質原卟啉IX（PPIX）、原卟啉鎂IX（MGPP）及原脫植醇葉綠素（Pchlide）之相對崩解速度的影響。資料顯示：（1）不論何種加熱方式，急速加熟的相對崩解速度都比漸進加熱快；（2）所有被檢測的色素之崩解速度是兩階段反應；（3）葉綠素的相對崩解速度比類胡蘿蔔素慢；（4）葉綠素a的相對崩解速度比葉綠素b快；（5）卟啉的相對崩解速度分別是原卟啉IX＞原卟啉鎂IX＞原脫植醇葉綠素。顯然的，自然界色素的崩解速度過程和水煮法造成的崩解不同。

We investigate the effect of two heating patterns, quick and gradual, on the relative degradation rate of chlorophyll, carotenoid, and the three intermediates, protoporphyrin IX (PPIX), magnesium protoporphyrin IX (MGPP) and protochlorophyllide (Pchlide), of chlorophyll biosynthetic pathway in three vegetable leaves. The data showed that (1) all pigments declined under both patterns of heating, however, the relative degradation rate of quick heating is greater than that of gradual heating; (2) The mechanism of all investigated pigments is a two-step reaction; (3) the relative degradation rate of chlorophyll is slower than that of carotenoid; (4) the relative degradation rate of chlorophyll a is faster than of that of chlorophyll b; (5) the relative degradation rate of protochlorophyllide is slower than that of magnesium protoporphyrin IX, which is slower than that of protoporphyrin IX; (6) nutrient content after gradual heating within 30 min is better than quick heating within the same period. We concluded that the degradation of leaf in nature is different from that in the heating condition of water.