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

The ultrasonic-assisted enzymatic extraction of lavender anthocyanin fromYili,Xinjiang was studied through single-factor experiments and response surface methodology. The optimum conditions were determined as follows:Pectinase dosage 0.10%,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 pH 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.