长链脂肪酸魔芋葡甘聚糖酯的制备及乳化性能研究

PREPARATION OF KNOJAC GLUCOMANNAN ESTERS OF LONG FATTY\=ACID AND STUDIES ON THE EMULSIFYING PROPERTIES

采用非均相酰化法制备了四个系列的长链脂肪酸魔芋葡甘聚糖酯（ＫＧＭＥ）．ＤＴＡ图显示了葡甘聚糖酯的晶态结构变化，Ｘ射线衍射分析表明了不同长度的酰链对葡甘聚糖酯晶态结构的影响．初步研究了葡甘聚糖酯在芳香烃及环烷烃两种水包油（Ｏ／Ｗ）乳液体系中其取代度与乳化力的关系．实验证明在水包油乳液体系中，取代度在某一范围的葡甘聚糖酯显示出较好的乳化能力，且在高盐浓度和酸性情况下，仍给出好的乳化作用．

Four series of konjac glucomannan esters (KGME) of long fatty acid are prepared by heterogeneous method.Differential thermal analysis (DTA) thermographs show the transitions of crystalline structure of KGME.With the increase of degree of substitution (DS) for palmitoylated konjac glucomannan (PKGM), the samples show new crystalline states at higher temperature and the former crystalline state of konjac glucomannan (KGM) disappears.X\|ray diffraction spectra indicate the effect of the length of acyl chain on the crystalline structure of KGME.At high DS of octanolylated KGM(OKGM), dodecanolylated KGM(DKGM), PKGM and octadecenoylated KGM(OLKGM) the intercrystalline distances are 210, 245,258 and 339nm,respectively,and the effect of DS of KGME on its emulsifying ability has been investigated in aromatic hydrocarbon in water and cycloalkane in water (O/W) emulsions.It is demonstrated that in the proper range of DS,KGME has good emulsifying ability in O/W emulsion,even in high salt concentration and in ac idic pH.Clove oil\|water (O/W) emulsion has good stability within four weeks at room temperature,and the breakage of emulsion was not brought about.\=