This article presents the experimental results on deacetylation of a konjac glucomannan (KGM) powder with alkali in mechanochemical (MC) treatment by a dry vibrating mill. It is indicated that the acetyl group of the KGM powder could be removed by means of the MC method. In addition, some characteristics, such as gel rheology, particle size/conformation, water absorbency, and thermal behavior, of the deacetylated KGM are analyzed. (c) 2008 Wiley Periodicals, Inc.