@article{oai:soar-ir.repo.nii.ac.jp:00017770, author = {Osada, Mitsumasa and MIURA, Chika and NAKAGAWA, Yuko S. and KAIHARA, Mikio and NIKAIDO, Mitsuru and TOTANI, Kazuhide}, journal = {Carbohydrate Polymers}, month = {Dec}, note = {This study examined the effects of sub- and supercritical water pretreatments on the physicochemical properties of crab shell α-chitin and its enzymatic degradation to obtain N,N′-diacetylchitobiose (GlcNAc)2. Following sub- and supercritical water pretreatments, the protein in the crab shell was removed and the residue of crab shell contained α-chitin and CaCO3. Prolonged pretreatment led to α-chitin decomposition. The reaction of pure α-chitin in sub- and supercritical water pretreatments was investigated separately; we observed lower mean molecular weight and weaker hydrogen bonds compared with untreated α-chitin. (GlcNAc)2 yields from enzymatic degradation of subcritical (350 °C, 7 min) and supercritical water (400 °C, 2.5 min) pretreated crab shell were 8% and 6%, compared with 0% without any pretreatment. This study shows that sub- and supercritical water pretreatments of crab shell provide to an alternative method to the use of acid and base for decalcification and deproteinization of crab shell required for (GlcNAc)2 production., Article, Carbohydrate Polymers. 134:718-725 (2015)}, pages = {718--725}, title = {Effect of sub- and supercritical water treatments on the physicochemical properties of crab shell chitin and its enzymatic degradation}, volume = {134}, year = {2015} }