Color

Many plant pigments are altered by cooking, which is why we can often judge by their color how carefully vegetables have been prepared. The one partial exception to this rule is the yellow-orange-red carotenoid group, which is more soluble in fat than in water, so the colors don’t readily leak out of the tissue, and are fairly stable. However, even carotenoids are changed by cooking. When we heat carrots, their beta-carotene shifts structure and hue, from red-orange toward the yellow. Apricots and tomato paste dried in the sun lose much of their intact carotenoids unless they’re treated with antioxidant sulfur dioxide. But compared to the green chlorophylls and multihued anthocyanins, the carotenoids are the model of steadfastness.