Extraction and fractionation of anthocyanins from red cabbage: ultrasonic-assisted extraction and conventional percolation method

We extracted the anthocyanins from red cabbage through ultrasonic-assisted extraction and conventional percolation method. The effect of ultrasonic output power, ultrasonic operation time and temperature, as well as ultrasonic pulse duration on the extraction efficiency was investigated. As a conventional method, red cabbage leaves were percolated in water to obtain the crude extract. We showed that ultrasonic irradiations enhanced the extraction of anthocyanins significantly in comparison to the conventional percolation method. The optimum extraction efficiency was obtained at ultrasonic output power of 100W, pulse mode of 30s ON: 30s OFF, at 15 degrees C for 90min. Fractionation of crude extract was further carried out using three different concentration of ethanol in ion-exchange column chromatography HP20. We demonstrated that the fraction obtained through the fractionation with ethanol/water (1:1) showed the highest antioxidant activity, anthocyanin content and phenolic compounds. [GRAPHICS] .