Organic and mineral acid demineralizations: effects on crangon and Liocarcinus vernalis – sourced biopolymer yield and properties

Chitin is chemically extracted from crustacean shells whose composition and structure differ from one another. It is reported that mineral acids distort chitin's physiochemical properties compared to organic acids. Investigations on the effectiveness of these acids on chitin isolation from crab and shrimp exoskeleton are carried out. Shell particles were demineralized using acetic acid (CH3COOH) and HCl while NaOH was used for deproteinization. Acetic acid possesses low potency for complete CaCO3 removal from crab shell while it fully demineralizes shrimp shell. With the use of CH3COOH, the biopolymer extracted shows characteristics of chitin but with lower content and physicochemical properties compared to chitin isolated from the shells using HCl. Mineral acid (HCl) will thus isolate chitin from exoskeletons of marine invertebrates irrespective of their shell nature while organic acid (CH3COOH) will be effective for soft shells whose embedded chitin content is more than the mineral content such as shrimp shells