Carotene is an orange dye that is found in many yellow, orange and red vegetables. It causes the color change in leaves when it comes fall and during the ripening of fruit. Carotene is important for photosynthesis, which takes place in the leaf under the influence of light. Carotene passes on the collected energy to the chlorophyll.
The color
Carotene is an orange colorant found in many vegetables. It’s an antioxidant. Vegetables with a lot of carotene are for example carrots, mangoes and tangerines. Leaves also contain carotene. Normally leaves are green. This is because the green parts of plants contain a light-absorbing pigment called chlorophyll. This absorbs red and blue light. Only green light bounces it back, making leaves green. Chlorophyll is in the chloroplasts, also called leaf green granules. When it is autumn and the temperature drops, the chlorophyll is broken down. The carotene in the leaves then remains. The leaves then change color and turn yellow or orange, for example. The same happens with the ripening of fruit: the green color of tomatoes or bananas, for example, disappears and then the orange, red or yellow color of carotene comes to the fore.
Photosynthesis
Carotene also has a very important role in photosynthesis. Photosynthesis is a process that uses energy from light to convert carbon dioxide into glucose and oxygen. Carotene passes on the energy collected to the chlorophyll in the leaf green granules. It also protects chlorophyll molecules against the harmful effects of sunlight, especially UV rays.
Carotenoids
The substance carotene is classified under the carotenoids, a large group of yellow to reddish dyes. Carotenoids are mainly found in the chromoplasts of plants. Chromoplasts are altered chloroplasts and add color to many plant parts. Carotenoids are divided into two groups: on the one hand, the xanthophyll group consisting of, among others, lutein and zeaxanthin. These contain oxygen atoms. On the other hand, you have the carotenes such as alpha carotene and beta carotene, which are made up of only carbon and hydrogen atoms. This makes carotenes soluble in fat but not in water.
Carotenoids are part of a larger group of plant compounds called terpenes. These compounds contain 10, 15, 20, 25, 30 and 40 carbon atoms. This suggests that they consist of “building blocks”. of five carbon atoms. The structure suggests that they are made by connecting isoprene units on a head to tail. way. Isoprene is the common name for 2-methyl-1,3-butadiene, the branched end of which is the ?? head ?? and the unbranched end is the “tail”, Carotenoids are tetraterpenes (eight isoprene units).
Plants only contain alpha and beta-carotene. The difference is in the position of the double bonds in the cyclic group at the end of the molecule. Beta carotene is more common than alpha carotene. The rule of thumb is: the more intense the orange color of the fruit or vegetable, the more Beta Carotene it contains. Alpha carotene is mainly found in roots. Taking too much carotene can lead to Carotenodermia, which turns the skin orange-yellow.