以黄芪甲苷为标准品,用香草醛-硫酸比色法于540 nm处测定黄芪总皂苷的含量.在单因素试验的基础上,应用Box-Behnken试验设计和响应面分析,探讨p H值、酶解时间、酶解温度和酶用量对黄芪总皂苷提取率的影响;对中心组合实验的结果进行方差分析,建立响应值与自变量的二次回归方程,并对模型方程进行验证.得到结果为模型极显著影响,且失拟不显著;得到纤维素酶辅助提取黄芪总皂苷的最佳工艺条件为p H值4.38,酶解时间132 min,酶解温度51℃,酶用量8.84 mg,预测提取率1.89%,实际提取率(1.87±0.03)%.建立的回归方程预测值与实际值吻合良好.
The optimal extracting processing for Astragalosides was investigated by response surface method. Astragaloside Ⅳ was used as the standard material,and vanillin-H2SO4 colorimetry method for the determination of Astragalosides in Astragalus. Based on the result of single factor experiments,the Box-Behnken design was used to investigate the effect of p H,reaction time,temperature and cellulase dose on the yield of Astragalosides. Analysis of variance showed that the model was significant while the lack of fit term was not significant. The optimum conditions for the yield of Astragalosides extracted from Astragalus were obtained through analyzing the experimental data by the Design Expert 8. 0 analysis software: p H 4. 38,reaction time132 min,temperature 51 ℃ and the cellulase dose 8. 84 mg. Experiments showed that the extraction rate was( 1. 87 ± 0. 03) % under this condition consistent with the theoretical prediction 1. 89%. Therefore,this model is useful to predict the yield of Astragalosides extracted from Astragalus.