Garlic, onion, chicory, cauliflower, potato, turnip…: why are these vegetables standing out compared to their multicoloured cousins?
Because it is their original colour
In the vegetable world, colours come from natural molecules called pigments. Chlorophyll is of course associated with green (oh, the pretty spinach!). As for tomatoes, they owe their intense red to the abundant presence of lycopene.
The white tint – or light beige or yellowish – of vegetables does not actually mean they have no pigments: cauliflower, turnip, garlic, salsifies or parsnip owe their light colour to pigments called anthoxanthins. In the vegetable world, white is therefore... a real colour!
Because we “force” them to be white
In other cases, white is the result of a gardener manipulation. For instance, asparagus’ colour does not come from their kind but from specific way of cultivating them: white ones grow under the ground without seeing the light of day. The green one grow outside where the “chlorophyll synthesis” happens, and the purple ones are lightly exposed to the light their tip comes out of the ground. The more they enjoy the sun, the more colourful they are!
Other example: chicory does not exist naturally. It is “forced” according to a technique created in the 19th century: the roots are removed and pricked out in darkness to prevent photosynthesis and obtain truly white leaves.
To know before starting to cook
To avoid white vegetables going yellow while cooking, you just need to add a bit of lemon juice or white vinegar to the cooking water. And the green in the white vegetables? We do not throw it away! Fresh tops - for example those of turnips - are lovely sautéed or in a gratin. As for cauliflower, its line, leaves and core transform into a delicious creamy soup.