Optimization of microwave-ultrasonic-assisted extraction of chlorogenic acid from Flos Lonicerae using response surface methodology

The microwave-ultrasonic-assisted extraction of chlorogenic acid from Flos Lonicerae was optimized using response surface methodology. The extraction yield of chlorogenic acid was investigated with respect to six process parameters including ethanol concentration,temperature,ultrasonic treatment time,solvent-to-solid ratio,microwave power and microwave time. As a result,a quadratic polynomial mathematical model was built.The optimal extraction conditions of RSM were determined as follows:Flos Lonicerae were suspended in microwave power of 400 W,microwaves 94 s,70% ethanol concentration at solvent-to-solid ratio 42∶1mL/g and then subjected to ultrasonic treatment for 60 min at temperature of 60℃. Under the modified conditions,the extraction yield of polyphenols was 5.45%.