Some guavas are white, but some are pink. Why?
The pink color comes from a specific type of molecule called the “Lycopene” molecule. It’s a long chain of 40 carbon atoms and 56 hydrogen molecules all strung together. When light falls on this molecule, it is able to absorb all parts of the light except the reddish part, which it reflects back. That’s why the molecule will appear red to our eyes.
Magic of nature
But where do these molecules come from?
By sheer magic of the plants. The guava plant is able to take the carbon and hydrogen atoms floating around them in the air, and “suck” them into the fruit, with the help of a little of energy from the sun(light). Inside the fruit, these molecules are “made” much like a factory.
When the factory produces a lot of lycopene, the guava appears pink. When there’s not much of it, the guava appears white.
Infact most fruits that appear reddish (hello tomato!) have Lycopene, or other similar molecules (for example Carotene) in them…all such molecules belong to the family of “carotenoids” (hello carrots!).
*Imagine that for a minute. Nature can take things that are invisible to your eyes, like the carbon and hydrogen atoms in the air, and turn them bright pink for you to see. *
Besides making the fruits look colorful, Lycopene molecules act as powerful antioxidants - they take out ‘loose cannon’ atoms in our bodies that can cause serious illnesses by damaging healthy cells in our body.
That’s one the reasons why the pink Guava is called a “super-fruit.”
Start with a slanted “D” shape and then fill out the shape of the skin. The interesting bit is the drawing the Lycopene molecule.
Observe that every Carbon atom has four “lines” going away from it. Each of those lines is a “electron bond”, an electron shared with a neighbouring atom. In nature, Carbon atoms desperately look for 4 bonds to be happy. Stop when you have drawn 40 of them.
Hydrogen atoms, on the other hand, wants one bond (one shared electron) to be happy. So you can see that every hydrogen atom has two lines going away from it. If you adhere to these two important rules of nature, for this molecule, you will notice that there will be exactly 56 hydrogen molecules.
Hence the formula for this molecule is C40H56.
Oh btw, give the background a nice pink will you?
More about carotenoids
Carotenoids - what they are, and where do they come from?
How about an interactive 3D model to the Lycopene molecule?