改性黄原胶酯化条件的优化及结构的表征

为了提高黄原胶的速溶性和粘度,将黄原胶进行改性处理。将黄原胶与马来酸酐进行酯化反应,探讨了黄原胶与马来酸酐摩尔比、反应时间和反应温度等因素的影响,以取代度为指标,利用响应面方法确定,该酯化反应的最优条件为:黄原胶与马来酸酐摩尔比1∶11.5、反应时间24.4 h、反应温度66℃。对改性黄原胶进行红外光谱、光散射和X-射线衍射等结构表征,表明酯化改性成功,且进一步解释了速溶性和粘度提高的原因。改性黄原胶细胞毒性实验,显示无毒性。结果表明,改性黄原胶的速溶性和粘度有很大提高,0.2%改性黄原胶的速溶性和粘度较对照提高了近3倍,在食品、药品等领域具有潜在的应用价值。

Optimization for esterification conditions and structure characterization of modified xanthan gum

In order to improve the instant solubility and viscosity of xanthan gum,xanthan gum was modified.Xanthan gum was esterified with maleic anhydride,and the effects of molar ratio of xanthan gum to maleic anhydride,reaction time and reaction temperature were investigated.Taking the degree of substitution as the index,the optimum conditions of the esterification were determined by response surface method as follows:the molar ratio of xanthan gum to maleic anhydride was 1∶11.5,reaction time was 24.4 h and reaction temperature was 66℃.The structure of modified xanthan gum was characterized by infrared spectroscopy,light scattering and X-ray diffraction.The results showed that the esterification was successful and the reasons for the increase of instant solubility and viscosity were further explained.The modified xanthan gum cytotoxicity test revealed no toxicity.The results indicated that the solubility and viscosity of 0.2%modified xanthan gum increased by nearly three times compared with those of the control.It had the potential application value in food,medicine and other fields.