Ultrasonic-assisted Pectinase Extraction and Identification of Anthocyanins from Rubus idaeus L.

In this study,pectinase assisted by ultrasonic method was used to extract anthocyanins from Rubus idaeus L.. The effects of pectinase dosage,ratio of material to liquid,enzymatic hydrolysis pH,enzymatic hydrolysis temperature,ultrasonic time and ultrasonic power on extraction were discussed through single factor test. The optimization of the extraction process was researched through the response surface test. The content of the three methods(ultrasonic assisted pectinase extraction,pectinase extraction and ultrasonic extraction)were compared. Also,the structure of anthocyanins from Rubus idaeus L. was identificated by ultra-high performance liquid chromatography in quadrupole/time-of-flight mass spectrometry(UPLC-Q/TOF). The results showed that,the optimized conditions were:pectinase dosage 5 mg/g,ratio of material to liquid 1:15 (g/mL),enzymatic hydrolysis pH3,enzymatic hydrolysis temperature 50℃,enzymatic hydrolysis time 60 min,ultrasonic time 20 min and ultrasonic power 450 W. Under the best condition,the anthocyanin content from Rubus idaeus L. was 127.51 mg/100 g and the identified anthocyanins were paeoniflorin-3-glucoside,cyaniding-3-glucoside,cyaniding-3-arabinosideand cyaniding-3-rutanose by UPLC-Q/TOF.