What is α-(alpha)-chitin?
Chitin can form long and strong fibers when chitin molecules align and crystallize. These chitin crystals can form in different ways. In α-chitin, the chitin chains are aligned in an anti-parallel way, i.e. the reducing ends of neighboring chitin chains point into opposite directions. This allows more hydrogen bonds to form between the two chains than in a parallel orientation, so that α-chitin crystals are denser, and α-chitin fibers are stronger than crystals and fibers formed from β-chitin. Most naturally occurring chitin is in the form of α-chitin, e.g. the chitin present in insect and crab shells as well as in fungal cell walls. Thus, almost all commercially available chitin is α-chitin.