Abstract:In order to improve the comprehensive utilization rate of Rubus idaeus pmace and extract the hypoglycemic components of Rubus idaeus pmace efficiently, in this study, flavonoid extraction and inhibition rate of α-glucosidase were used as indexes to optimize the extraction technology of hypoglycemic components in Rubus idaeus pmace assisted by high speed shear ultrasonography. The response surface method was used to optimize the main process parameters. The results of ANOVA showed that the regression model reflected the relationship between flavonoid extraction amount and ethanol concentration ratio, extraction temperature and ultrasonic treatment time. The best process conditions: high-speed shear emulsifying machine speed of 14000 r/min, extracting temperature of 55 ℃, ultrasonic time of 26 min, shear time of 40 s, ultrasonic power of 210 w. Under this condition, the inhibition rate of α-glucosidase was (65.56±0.11)%; the content of flavonoids in Rubus idaeus pmace was (39.11±0.16) mg/g. The method has an advantage in extracting efficiency and activity retention. Comparing to the use of the ultrasound process and the high shear technique, this method increased by 117.45% and 112.17% of the flavonoids contents in Rubus idaeus pmace, respectively; and increased by 47.85% and 43.79% of α-glucosidase inhibition, respectively. The efficient extraction of flavonoids from Rubus idaeus pmace also provided a new way for the extraction of hypoglycemic substances.
