超声辅助酶法提取薰衣草花色苷及其热降解动力学

Ultrasonic-assisted Enzymatic Extraction and Thermal Degradation Kinetics of Anthocyanins from Lavender

以新疆伊犁熏衣草为研究对象,通过单因素实验和响应面试验研究超声辅助酶法提取薰衣草花色苷,确定最佳工艺条件为:在果胶酶质量分数为0.10%、pH3、乙醇浓度50%、酶解温度50℃、酶解时间62 min、超声时间25 min,该条件下薰衣草花色苷得率为6.22%,较单一超声提取法相比,超声辅助酶法具有明显的优势。通过对不同pH和温度下薰衣草花色苷稳定性的研究发现,不同pH下薰衣草花色苷热降解符合一级动力学方程;在相同p H下,花色苷降解所需要的能量势垒大小与温度无关;薰衣草花色苷热稳定性较差,当p H6.0时,其对热最为敏感,pH1.0时,其热稳定性最强。

The ultrasonic-assisted enzymatic extraction of lavender anthocyanin fromYili,Xinjiang was studied through singlefactor experiments and response surface methodology.The optimum conditions were determined as follows:Pectinase dosage0.10%,enzymatic hydrolysis pH3,ethanol concentration 50%,enzymatic hydrolysis temperature 50℃,enzymatic hydrolysis time 62 min,ultrasonic time 25 min.Under the best condition,the extraction rate of lavender anthocyanin was 6.22%,this method has obvious advantages compared with single ultrasonic extraction method.The study on the stability of lavender anthocyanins at different pH values and temperatures showed that the thermal degradation of lavender anthocyanins at different p H values accorded with the first-order kinetic equation.At the same pH value,the energy barrier required for anthocyanin degradation was independent of temperature.Lavender anthocyanin had poor thermal stability.When pH was 6.0,it was most sensitive to heat.At pH1.0,its thermal stability was the strongest.