Optimizing of ultrasonic wave-assisted extraction process of tea-polyphenols substance from green tea

【Objective】 The present study aimed to optimize ultrasonic wave-assisted extraction process of tea-polyphenols substance to provide theoretical parameters for its exploiture extraction and comprehensive utilization.【Method】 With Ziyang population variety as test material,quadratic orthogonal rotation combination design was used to optimize ultrasonic wave-assisted extraction process of tea-polyphenols substance.【Result】 A quadratic regression orthogonal model was established to express the relationship between total polyphenol yield and five factors including ratio of solid to liquid,ethanol concentration,ultrasonic time,ultrasonic temperature and ultrasonic Power;Equation fit test P0.000 1,coefficient of determination R2 = 0.926 0,loss of fit test P=0.223 40.05 not significant,the model was extremely significant,and there was no loss of fit factors,regression models with the measured values can be well fitted.The factor order on extraction yield from strong to weak was ratio of solid to liquidethanol concentrationultrasonic temperatureultrasonic timeultrasonic Power.According to this model,the best extraction technology is based on ultrasonic extraction at 72.1 ℃,248.4 W for 37.6 min using 77.6% ethanol and 1∶35.8(g/mL) of green tea and liquid.【Conclusion】 The optimal ultrasonic wave-assisted extraction conditions were determined.On the conditions the highest yield of tea-polyphenols was 21.78%.Compared to the traditional organic solvent extraction method at the same condition,the yield of TP was enhanced by 8.56% and the extraction time was reduced.