Optimization of Extraction Technology of Anthocyanidins from Daucus carota L. by Aqueous Two-phase System Based on Response Surface Methodology

In this study, the anthocyanins in Daucus carota L. were extracted and purified by PEG/ammonium sulfate aqueous two-phase system. The mass content of ammonium sulfate, the mass content of PEG6000, and the mass content of crude extract were optimized by single factor experiment according to the selectivity coefficient and extraction ratio of anthocyanins. Based on the response surface experiment, with the extraction ratio of anthocyanins as the response value, the extraction process was optimized. The results showed that the influence order of various factors on anthocyanins extraction effect was as follows: the ammonium sulfate content>the crude extract content>the PEG6000 content. Based on the total mass of the aqueous two-phase system, the optimal extraction condition was as follows: the mass content of ammonium sulfate, crude extract and PEG6000 was 20.0%, 12.0% and 14.0%, respectively, and the average extraction ratio of black carrot red color was 94.17%. The black carrot red color extracted by this method had certain antioxidant activity, and the IC₅₀ value of the DPPH free radical scavenging ability was 30.51 mg/L.