In addition to attracting attention, the colors in fruits and vegetables also indicate nutrient content in it. For each color of food is formed from the dominant type of nutrition that is different.
Quoted from Canadianliving, Monday (06/09/2010), some colors that shows that it contains essential nutrients are as follows.
Red
The red color in tomatoes showed lycopene, an antioxidant compound that is capable of reducing the risk of cancer and heart disease. The same compound can also be obtained from watermelon fruit.
Activity of lycopene in tomatoes is not reduced when heated, such as when made into a sauce or tomato sauce. The addition of olive oil into it is not reducing benefits, because lycopene is an oil-soluble compounds.
Other Ingredients that gives red color to foods is anthocyanin, which is also an antioxidant compound. Anthocyanins can be found on strawberries, raspberries and cranberries.
Green
Not without reason that many health experts recommend to a lot of green vegetables. The green color is formed by chlorophyll, a compound that has proven effective against cancer.
Some vitamins and minerals can also be found in fruits and green vegetables. Green lettuce contains vitamin C six times more than white lettuce, and beta carotene 8 times more.
While the levels of nutrients contained in vegetables and fruits can be estimated from the intensity of green color. The more dense or dark green color, then the content of vitamins and minerals more and more.
Blue or gray
The blue color in blueberries and purple on the grapes, eggplant and blackberries pigment formed by the same, namely anthocyanins. These compounds are also commonly found in red wine fermented beverages (red wine) and is believed good for heart health.
Fresh blueberries contain more anthocyanins, although not decreased in the fruit that has been frozen. Eggplant can also be baked or roasted in advance without much loss of anthocyanin content.
Orange
Nutritional most dominant in the fruit and orange or orange-colored vegetables are beta and alpha carotene. Nutrition can be found in sweet potatoes, carrots, apricots, mango and orange melon is also known as anticancer compounds.
Because these compounds are soluble in oil, absorption in the body can be increased if consumed with fatty foods. Can also be cooked through, for heating for several minutes it breaks down the cell walls in vegetables and fruits and then frees bound form of the compound.
source: (http://www.detikhealth.com/read/2010/09/10/135658/1438826/766/kandungan-gizi-dalam-berbagai-warna-buah-dan-sayuran)