找到了一个说法，看来最好是粉碎了

来源: dudaan 于 2016-03-02 18:42:20 [档案] [博客] [旧帖] [给我悄悄话] 本文已被阅读：次 (1520 bytes)

回答: 不懂为什么要静置由 dudaan 于 2016-03-02 18:18:23

Did you know that cutting the florets into smaller pieces and the stems into thin slices and letting them sit for 5 to 6 minutes before cooking will enhance their cancer protective properties? Cutting broccoli into smaller pieces breaks the cells and activates an enzyme called myrosinase. The myrosinase converts some of the sulfur-containing chemicals found in broccoli (call glucosinolates) into other sulfur containing chemicals (called isothiocyanates) which research has shown to contain cancer preventive properties not found in the glucosinolates . Studies have actually pinpointed specific mechanisms, like changes in cellular genetic processes, which are involved in increasing cancer protection.

Since myrosinase is specifically activated by ascorbic acid (vitamin C), sprinkling your sliced broccoli with a little lemon juice, an excellent source of vitamin C, before letting it sit may also help increase myrosinase activity. Once broccoli is heated, even if it is just lightly steamed, the myrosinase enzyme will become inactivated. For this reason, the slicing of broccoli 5-6 minutes before steaming will enable the enzyme to go to work and convert some of the sulfur-containing compounds prior to steaming.