Optimization of ultrasound-assisted extraction conditions for extraction of bioactive compounds from purple carrot (Daucus carota L.) using response surface methodology

Abstract

Statically-based optimization was employed to maximize the total phenol content, total flavonoid content, and radical scavenging activity from purple carrot (Daucus carota L.) using ultrasound-assisted extraction. To enhance the extraction of bioactive components, key variables of ultrasound-assisted extraction including extraction time (5.0 ~ 55.0 min), extraction temperature (26.0 ~ 94.5 °C), and ethanol concentration (0.0 ~ 99.5%) were chosen as independent variables and optimized using Response surface methodology. The optimal extraction conditions were predicted as 41.9 °C, 46.1 min, and 26.0% ethanol, under these conditions, total phenol content, total flavonoid content, and radical scavenging activity were found to be 16.1 mg GAE/g DM, 0.86 QE/g DM, and 25.6%, respectively, similar to the experimental values of the validation experiment. When the purple carrot extract was analyzed using HPLC, chlorogenic acid was identified as a main substance. Therefore, ultrasound-assisted extraction can effectively increase the anti-oxidant production of purple carrot, and purple carrot extract has high potential as functional food and cosmetic raw material.

Keywords:
purple carrot; optimization; ultrasound-assisted extraction; central composite design; anti-oxidant