Simultaneous extraction and enrichment of polyphenol and lutein from marigold (Tagetes erecta L.) flower by an enzyme-assisted ethanol/ammonium sulfate system

Enzyme-assisted aqueous two-phase extraction (EA-ATPE) using ethanol/ammonium sulfate system was investigated for total polyphenol (TP) and lutein from marigold flowers. The important factors were investigated by single factor experiment and response surface methodology combined with Box–Behnken design to optimize the operating parameters of EA-ATPE. The maximum yields of TP and lutein were 83.56 ± 0.69 mg g−1 and 5.59 ± 0.13 mg g−1, respectively. Compared with aqueous two-phase extraction and Soxhlet extraction (SE), the extraction yield of TP by EA-ATPE is 64.91% higher and the extract of EA-ATPE has better antioxidant activity. The pretreatment effect was also researched by scanning electron microscopy. Thus, EA-ATPE is an efficient method for extracting bioactive components from plants.