Optimization of extraction technology of proanthocyanidins from the larch bark by supercritical CO2 assisted and the ultrasonic enhanced

This thesis combined supercritical fluid extraction and Ultrasonic technology, studied on the extraction technology of procyanidins in the larch bark.Firstly, lipophilic component was extracted through using supercritical CO2, and then procyanidins was extracted from the raffinate with the ultrasonic wave.The 5 influence factors of procyanidins was examined:ultrasonic digestion rate, raw material particle size, solid-liquid ratio, ultrasonic time, ultrasonic number.On the basis of a single factor experiment and orthogonal experiment, the optimum process conditions of ultrasonic assisted extraction of the Larch bark procyanidinsin was selected :60% ethanol solution as the solvent, the raw material particle size of 80¹00 mesh, solid-liquid ratio 1 ∶12 (g/mL) , using ultrasonic of 320W for 20min, two times, the extraction ratio of procyanidins was achieved 10.44%, solid content digestion rate was 22.85%, the procyanidins content was 44.29%.The surface morphology analysis of the bark before and after the extraction with ultrasonic wave methods by SEM showed that the fiber structure of bark had been damaged with different degrees.Hence promoting extraction efficiency has an effect on the procyanidins in the larch bark for future.