It's week two of my colorful foods project: Orange foods. Where red foods can get their pigment from many different types of molecules, orange foods primarily get their pigment from carotenoids. Carotenoids can make red, yellow or orange pigments in plants. For animals they can satisfy several essential nutritional functions, notably vision. Part of the light receptor molecules at the back of your eye come from vitamin A molecules. And during digestion orange beta carotene is converted to vitamin A. The little light receptor molecules at the back of your eye that are allowing your eye to read this all originally came from some colorful (and likely orange or yellow) plant. We do ingest some vitamin A through animal foods, like butter and egg yolks (also orange/yellow), but those animals got their vitamin A from a plant with carotenoids. So carotenoids, I think, deserve a special nod in this homage to food color.
Bright, stable dependable carotenoids also present the home cook a number of opportunities for cooking. Carotenoids are the most stable of the four types of molecules that create plant pigments- acid and heat (which can send anthocyanins and chlorophylls all over the spectrum) will barely affect carotenoids. So roast your sweet potatoes, grill your peppers - they'll happily stay bright orange. Of course when you concentrate the color (by, say, removing some moisture) the orange hue will appear darker and more red. The one disadvantage of carotenoid's stability is that it is a little tricky to find natural orange food dyes. Carrot juice works well if you want to color a liquid orange, but for water soluble dyes you'll have to get a little more creative. Most orange food dyes are made by combining red and yellow pigments (water soluble red and yellow pigments are easier to come by than orange). A mix of red and golden beet juice can make a brilliant orange food dye.
Carrots - The namesake of the carotenoid family, carrots typically have a brilliant orange color (though heirloom varieties can have purple or yellow flesh). Try adding carrot juice to sauces or vinaigrettes in place of water, for a brilliant orange color.
Sweet Potatoes - Take a peek in just about any nutritionists recipe book, and you'll find recipes with sweet potatoes. Compared to their paler cousins, sweet potatoes are packed with vitamins. Sweet potatoes cook similarly to other types of potatoes, so you can experiment with swapping sweet potatoes if you want a little extra orange in your life. Among the many sweet potato varieties, the color is a good indicator of how a sweet potato will taste. Red or purplish varieties will have a delicate flavor while the more intensely orange sweet potatoes have a big, earthy, pumpkin flavor. Longer, slower cooking will give you sweeter sweet potatoes.
Curry - Curry powder appears orange, but it's kind of a trick. Turmeric (a powerful yellow coloring) is one of the main ingredients in curry powders. Mixed with other brown and reddish spices, the overall effect is often orange. (For more on turmeric, stay tuned for next week's post on yellow...) Still, when you're working with curry powders or pastes, the prevailing color of the sauce or meet tends to be orange.
Stone Fruits - The flesh of peaches, nectarines and apricots can range from pale yellow to vivid orange. Once cut, the fruit quickly begins to oxidize, and the color will be muddied by a brown tint on the surface of the fruit. Squeeze an acidic citrus juice over the surface of cut fruit to keep your fruit bright and colorful. When they are dried, apricots and peaches are typically treated with sulfur dioxide to help preserve their vivid color and tangy, fresh flavor.
Mangoes -The orange color of mangoes is particularly stable and vivid. Add some chopped mango to your salsa to give it a colorful, sweet twist. Or, really, add mangoes to just about anything.
Melons- Many winter melons have pale orange flesh (cantaloupe, muskmelon). The orange color in these fruits is very stable, and holds up well when exposed to air. No wonder melons are a favorite staple for fruit salads. Dehydrated melon has a very sweet, intense flavor. if you cut melons into slices and dry them, you'll get a translucent shards-- perfect for a striking accent to a dessert or fruit dish.
Oranges - Oranges as well as much of the citrus fruit family are proudly orange. Strips of orange zest can make a pretty (and edible) garnish or colorful accent to a dish.
Squash - While summer squash may have brilliant green and yellow skin, the interior flesh is very pale. The inside of hard, winter squash is almost always orange, though the color intensity can vary. Winter squash typically have a lot of water and air in their flesh. To get the best flavor, pick a cooking technique that will remove moisture and concentrate both flavor and color (slow roasting works well).
Peppers & Tomatoes - Certain varieties of peppers and tomatoes have great orange pigments. Fiery little habaneros have a beautiful creamsicle-orange hue, but you probably don't want to use enough of them to add color to a plate. When they are in season look for orange colored peppers and tomatoes. Again, that orange color is hard to mess up, so try any cooking technique on these babies, and you'll get a bright, colorful result.