Take a look at a dish with green vegetables. If they are bright green, we are more likely to think it is a delicious dish.
But when we cook green vegetables, they can turn dull green and look unappetizing (maybe that’s why kids don’t like greens?). How can we make them bright green instead? We can do so by salting the greens!
The science behind the color change has to do with chlorophyll and the organic acids found in plant cells. Chlorophyll is found in the chloroplasts of plant cells. They are the main green pigment found in green vegetables. When green vegetables are heated, the cells in them start to denature i.e. lose their structure, and the organic acids in the cells leak out.
These organic acids then react with the chlorophyll. The magnesium atoms in the chlorophyll are replaced by hydrogen atoms, which causes the vegetables to look dull green. As the original bright green fades, the orange and yellow pigments in the plant become more visible, combining to give the greens a brownish dirty look.
The dull and dirty appearance can be avoided by salting the greens with sodium bicarbonate (NaHCO3, also more commonly known as baking soda). The Na ions replace the methyl alcohol (CH3-OH) and phytyl alcohol (C20H40O) groups, forming chlorophyllin.
Chlorophyllin is a bright green pigment, thus turning your cooked vegetables into an appetizing green. When paired with other ingredients and foods, the greens help to make the dishes mouth-wateringly colorful.
Adding sodium bicarbonate to water however makes it alkaline. Many vitamins are not stable in an alkaline solution. Hence the trick is to use just a little – literally to take all this with a pinch of salt (of sodium bicarbonate); after all, salting the greens does not mean we assault them with lots of salt!
photos: in order - istockphoto/showcake; depositphotos/thiroil; roxanabalint; Photon; jordache; gnohz