Vegetables come in n rainbow of colors, from beautiful white to vibrant green, bright orange and deep red. This is due to the presence of certain pigments in their cells.

These pigments can be classified under 3 main categories:

  1. Chlorophyll (green vegetables)
  2. Carotene (orange-yellow vegetables)
  3. Flavonoids (white and red vegetables)

To maintain their vibrant, natural color and flavor during cooking, it is important to understand that each category should be treated differently.

  1. Chlorophyll (green vegetables)

Green vegetables, such as broccoli, asparagus or green beans contain the pigment: chlorophyll

It is very sensitive to heat and acid. If thrown briefly into boiling water, it will become vibrant and bright. However with prolonged cooking, it will suffer major color lose. Also if green vegetables are cooked in a liquid with an acid, such as lemon juice or vinegar, they will quickly turn from bright, green color to dull, olive green color as shown here:

Green vegetable do contain small amount of natural acid, which will leak out during cooking, so cooking greens in plenty of water will help them to preserve vibrant, green color.

It is also important to cook vegetables without a lid, so the acids do not condensate on the lid and fall back into the cooking liquid. Adding baking soda to neutralize the acidity it is not recommended as it can make vegetables bland, mushy and soapy taste.If you are serving your greens with sauce or vinaigrette it is best to do it just prior to serving to prevent the color from changing.

  1. Carotene (orange-yellow vegetables)

Orange and yellow vegetables, such as carrots, sweet potatoes, and squash contain the pigment carotene. This pigment is very stable, and can generally tolerate any method of cooking, whether with an acid, or without, or with a lid or without.  If adding an acid, it is recommended to ad it half way through, as acids tend to keep vegetables firm. Adding it half way through will allow the vegetables to become tender and preserve their natural color.

  1. Flavonoids (white and red vegetables)

Red and white vegetables and fruits contain various flavonoids pigments. These range from red and purple fruits and vegetables, such as:  blue berries, red cabbage, red onions, and red beets to white fruits and vegetables, such as: parsnips, mushrooms and cauliflower. These pigments generally require the presence of an acid, in order to preserve their color, approx. 1 to 2 Tbs of acid per liter or quarter is sufficient. For example, add a bit of red wine to red cabbage to preserve it is vibrant color, same with blueberries, add them fresh to a bit acidic batter so they stay vibrant purple, even after frying.

Also, when cooking different colored vegetables that leach color, such as red or gold beets, it is important to cook them separately in order to maintain their individual colors.

For white pigmented vegetables, such as: parsnips, mushrooms and cauliflower, adding acid, such as lemon juice will help them to keep white during cooking.  On the picture below, the bright white cauliflower was cooked with an acid.

As those vegetables benefit from acid, they do not mind being cooked with lid on.


This text is part of educational materials given by ROUXBE: