柑橘果胶磷酸化制备工艺优化及其改性品质分析

Optimized Preparation Process of Citrus Pectin Phosphorylation and It's Modified Quality Analysis

在单因素试验的基础上,以复合磷酸试剂浓度、反应温度、反应时间和pH值为变量,以产品中磷酸根含量为响应值,采用Box-Behnken Design中心组合法对柑橘果胶的磷酸化制备工艺进行研究,结果表明,影响磷酸化果胶中磷酸根含量的主次因素为反应温度>磷酸化试剂浓度>反应时间>pH值;所得模型呈高度显著性(P<0.0001),在93.1%的水平上能够拟合试验数据,可较好地阐明产品中磷酸根含量与反应条件的关系;模型经优化得到的最佳制备工艺条件是:磷酸化试剂质量浓度0.11 g/m L、反应温度78℃、反应时间4.2 h、pH=8。经试验验证,产品中磷酸根实际含量为(1.31±0.03)%(n=3),与预测值1.36%接近;同时,分析了改性产品的品质指标。本磷酸化果胶制备优化工艺,为柑橘果胶的产品多样化开发及其在功能性食品、药品等方面的应用提供了理论依据。

On the basis of the single factors, a phosphorylated modification of citrus pectin was researched by Box- Behnken Design with phosphate content of the product as the response value, the variable of composite phosphoric reagent concentration, temperature, time and pH. The experiment results indicated that the effects of phosphate content on phosphorylation of citrus pectin＇s primary and secondary factors were reaction temperature 〉 phosphorylation reagent concentration 〉 reaction time 〉 pH; Statistical analysis showed that the obtained model was highly significant （P〈0.0001）, and at the level of 93.1%, this model can fit the experimental data, it was able to clearer interpret the relationships of content of phosphate products and reaction conditions. After optimization, the optimal preparation conditions are the phos-phorylation reagent concentration 0.11 g/mL, the reaction temperature 78℃, reaction time 4.2 h, and pH 8. Under the optimized conditions, it can be included that the phosphate content （1.31 ± 0.03）% （n = 3）, which were close to the es- timated value （1.36%） attained by using optimized process. At the same time, conventional physical and chemical prop- erties of pectin were measured respectively before and after modification. Therefore, the preparation conditions by the Box-Behnken Design was true and reliable, and this condition was able to provide a theoretical basis and some reference significance to the diversification of pectin products and the applications in functional foods or medicines, etc.