Optimization of Lutein Enrichment from Calendula by Subcritical Fluid Extraction

In this paper,Calendula particles were used as the research object. Based on the single-factor test and Plackett-Burman test design,the effects of Calendula particle size,extraction time,extraction pressure,extraction temperature and number of extractions on lutein extraction process were explored,the Box-Behnken central test design was used to optimize the subsurface fluid(R134a)extraction and enrichment of lutein. The results showed,under single factor conditions,the size of Calendula,extraction time,extraction pressure,extraction temperature and extraction times all had an certain effect on the enrichment of lutein content. The Plackett-Burman test was used to screen out the three factors which had significant effects on the enrichment of lutein content,including extraction time,extraction temperature and extraction times. The selected three factors were optimized for subcritical fluid extraction and enrichment of the xanthophyll response surface in marigold flowers. The optimal process was:Calendula particle size 10 mm,extraction time 44 min,extraction pressure 1.2 MPa,extraction temperature 39 ℃,extraction times 4 times. Under this condition,the concentration of lutein in the subcritical extract reached 32.28%,which was 0.44% different from the predicted value. At the same time,the effect of subcritical fluid extraction of lutein was significantly higher than that of organic solvent extraction and supercritical CO₂ extraction. This study can provide a theoretical reference for the industrialization of lutein in Calendula.