星点设计-效应面优化广西莪术挥发油的提取工艺

采用星点设计-效应面优化方法研究广西莪术（Curcuma kwangsiensis S．G．LeeetC．F．Liang）挥发油的提取工艺，星点设计中的考察因素为加水倍量和提取时间，用水蒸气蒸馏法提取挥发油，以总挥发油的体积作为评价指标，对各因素的各水平进行二项式拟合，按二项式描绘三维效应面，从三维效应面上选取对总挥发油的体积较佳的实验条件。结果二项式拟合复相关系数较好，r=0．98157，最佳提取工艺为：加水8倍，提取时间6．5h。依最佳条件提取的挥发油体积为0．742ml，与理论预测值的偏差为-1．45％。星点设计-效应面优化法对提取广西莪术挥发油的实验指标具有较好的优选性和预测性。

Central Composite Design-Response Surface Methoclology on the Extraction Process of Curcuma kwangsiensis

We obtain the optical volatile oil extraction of Curcurna kwangsiensis by Central Composite Design-Response Surface Methoclology. Independent variables of the experimental design were water volume and extraction time. The essential oil were obtained by steam distillation. The volumes of the volatile oil were used as estimation index, and linear or nonlinear mathematic models were used to estimate the relation between independent and dependent variables. The bulk of the volatile oil were fitted to a second-order Polynomial eqation, surface graghs were produced. Optimum experimental conditions were selected from the stationary point of the response surfaces. The coefficient of correlation of second-order quadratic model was high. It reached 0. 98157. The optimum condition was 8 times amount of water,and extraction time was 6.5 hours. The volumes of the volatile oil were 0. 742. Bias between observed and predicted values were -1.45 %. It shows that the optimum model is highly predictive.