An innovative method for preparation of acid-free-water-soluble low-molecular-weight chitosan (AFWSLMWC)

The ozone generated from compressed oxygen by a laboratory-scale corona discharge generator was used for the preparation of acidfree-water-soluble low-molecular-weight chitosan (AFWSLMWC). Factors affecting the percent yield of AFWSLMWC were studied in batch experiments. AFWSLMWC with a molecular weight of 4.3-13.1 kDa was obtained. IR spectra demonstrated that the chemical structures of AFWSLMWC were not modified during the depolymerisation process. There was no significant change of the total degree of deacetylation (DD) of AFWSLMWC, compared with the initial chitosan. The method is promisingly suitable for scale-up manufacture of acid-free-water-soluble low-molecular-weight chitosan. (C) 2007 Elsevier Ltd. All rights reserved.