Do your green vegetables lose their vibrant colour when you cook them? Follow the golden rule of cooking them for 7 minutes or less and they will retain that fresh colour, says the American Chemical Society.
Here's the science behind it: Magnesium in the vegetable is responsible for the fresh green colour. When heated, the cells break down and magnesium is replaced by hydrogen, which changes the colour. The 7-minute rule limits the amount of cell damage, thus preserving the more appetising colour.
The Splendid Table adds that it also affects the flavour, too:
Members of the genus brassica (cabbage, cauliflower, broccoli, Brussels sprouts, kale, mustard, rutabagas, collards, turnips, etc.) become stronger and more unpleasant the longer you cook them. Even 2 to 3 minutes additional cooking time matters. The amount of strong-smelling (the smell of rotten eggs) hydrogen sulfide gas that comes off of cabbage doubles when you cook it 7 minutes instead of 5. Cabbage that is slivered fine (as for slaw) can be cooked in a few minutes. Serve with buttered bread crumbs or herbs, it is sweet and mild. You will notice a major change in sweetness and mildness of these vegetables if you come up with creative ways to cut them into small pieces that will cook in a short time.
Check out the full video by Reactions for more chemistry-based hacks to make your life easier, including putting old eggs in water to see if they have gone bad.
4 Chemistry Life Hacks for Everyday Problems [Reactions]
Do you like your vegetables green? Keep their cooking time under 7 minutes [The Splendid Table]