title: Effect of degree of acetylation on gelation of konjac glucomannan.
abstract: Effect of the degree of acetylation (DA) on the gelation behaviors on addition of sodium carbonate for native and acetylated konjac glucomannan (KGM) samples with a DA range from 1.38 to 10.1 wt % synthesized using acetic anhydride in the presence of pyridine as catalyst was studied by dynamic viscoelastic measurements. At a fixed alkaline concentration (CNa), both the critical gelation times (tcr) and the plateau values of storage moduli (G'sat) of the KGM gels increased with increasing DA, while at a fixed ratio of alkaline concentrations to values of DA (CNa/DA), similar tcr and values independent of DA were observed. On the whole, increasing KGM concentration or temperature shortened the gelation time and enhanced the elastic modulus for KGM gel. The effect of deacetylation rate related to the CNa/DA on the gelation kinetics of the KGM samples was discussed.
authors.affiliation: Department of Food and Human Health Sciences, Graduate School of Human Life Science, Osaka City University, Sugimoto, Sumiyoshi, Osaka 558-8585, Japan. gaosjwhu@21cn.com
authors.forename: Shanjun
authors.initials: S
authors.lastname: Gao
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Nishinari
mesh_terms: D000107:Acetylation; D000468:Alkalies; D005782:Gels / Q000737:chemistry*; D008351:Mannans / Q000737:chemistry*; D044367:Phase Transition; D013696:Temperature; D014783:Viscosity
chemical_list: D000468:Alkalies; D005782:Gels; D008351:Mannans; C022901:(1-6)-alpha-glucomannan