What are the origins of the names “chitin” and “chitosan”? To answer this question, we need to take a look at their chemical structural formulas.
The structural formulas of chitin and chitosan are almost the same. The only difference is their terminal, where chitin has -NH(COCH3) and chitosan has -NH2.
Chitosan rarely exist in nature. They are present mostly in the form of chitin. For example, the much-hyped mushroom chitosan is a product of chemical processing of chitin. Crab chitosan is also derived in the same manner.
However, 2 - 3% of naturally occurring chitin has -NH2 at its terminal instead of -NH(COCH3) in its structural formula above. This means that chitin contains 2- 3% chitosan by nature. Therefore, it is not entirely wrong to call “chitin/chitosan.”
That was a little technical talk. I hope you understand. Next, we will talk about the quality of chitosan.