Have you ever noticed that after eating spinach, a layer of rough grainy substance covers the teeth? The scientists have analyzed that this gritty layer is made with a chemical.
Often leafy vegetables contain a chemical called oxalic acid that is also found inside spinach in a higher amount as compared to other green plants. The research was led by Prof. Jim Correllfrom from University of Arkansas, US who compared the amount of oxalic acid between various green plants and spinach.
The study showed that spinach uses oxalic acid to protect itself from several creatures such as insects who tries to eat them.
The scientists have noticed that many other substances in spinach along with oxalic such as beta carotene, lutein, folate, vitamin C, iron, phosphorous, potassium and calcium, play an essential role.
Amalgamation of these compounds gives you a weird layer over the teeth. While explaining the process the scientists added that oxalic acid blends with calcium that makes calcium oxalate.
This combination creates a small crystal that does not blend in water and floast inside the mouth that gives you an unusual feeling and texture.