Physicochemical characterization of chitin and chitosan from crab shells

摘要: Abstract Crab chitosan was prepared by alkaline N -deacetylation of crab chitin for 60, 90 and 120 min the yields were 30.0-32.2% with that C120 being highest. The degree chitosans (83.3–93.3%) increased but average molecular weight (483–526 kDa) decreased prolonged reaction time. showed lower lightness WI values than purified chitin, CC CS higher crude chitin. With time, nitrogen (8.9–9.5%), carbon (42.2–45.2%) hydrogen contents (7.9–8.6%) in consistently whereas N/C ratios remained same (0.21). a melting endothermic peak at 152.3–159.2 °C. Three similar microfibrillar crystalline structure two reflections 2 θ  = 8.8–9.0° 18.9–19.1°. Overall, characteristics three unique differed from those as evidenced element analysis, differential scanning calorimetry, electron microscopy X-ray diffraction patterns.