Process optimization for ultrasonic-assisted extraction of anthocyanins from Lycium ruthenicum Murray

The ultrasonic-assisted extraction process of anthocyanins from Lycium ruthenicum Murray was optimized by response surface methodology in this paper. Total anthocyanins content as index, the liquid to solid ratio, extraction temperature, extraction time and ethanol concentration were selected as the main factors through the single factor experiment.Thus the BoxBehnken experimental design was carried out with four factors and three levels and the response surface methodology was applied to optimize the extraction conditions.The results indicated that the optimal extraction conditions were determined as follows: the liquid to solid ratio of 20.4 ∶ 1 ( m L/g) , extraction temperature of 48 ℃, extraction time of 24.8 min and ethanol concentration of 79%.Under the above conditions, the extraction content of anthocyanins could reach ( 14.999 ± 0.014) mg/g. The primary and secondary order of the factors affecting the extraction content of anthocyanins was extraction temperature, alcohol concentration, extraction time, and liquid to solid ratio.