title: Subcritical water extraction and antioxidant activity evaluation with on-line HPLC-ABTS(·+) assay of phenolic compounds from marigold (Tagetes erecta L.) flower residues.
abstract: Subcritical water extraction (SWE) of phenolics was investigated from marigold (Tagetes erecta L.) flower residues. The total phenolics content (TPC), total flavonoids content (TFC) and antioxidant capacities of extracts were determined, furthermore, antioxidant activities of individual compounds were evaluated with on-line HPLC-ABTS(•+) system. The optimum SWE time was 45 min, solid-to-liquid ratio was 1:50, and the highest TPC and TFC were obtained at 220 °C respectively. The effect of SWE temperature on TPC and TFC was significant (p < 0.05), and TPC was ranged from 28.42 ± 0.94 to 124.27 ± 1.94 (mg GAE/g), and TFC ranged from 34.21 ± 0.36 to 133.22 ± 1.57 (mg GAE/g) between 80 and 220 °C. On-line HPLC-ABTS(•+) profiles revealed that quercetagetin from SWE at 200 °C had nearly twofold radical scavenging activities than that by leaching extraction.
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, , Haidian District, Beijing, 100083 China.
authors.forename: Honggao
authors.initials: H
authors.lastname: Xu
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, , Haidian District, Beijing, 100083 China.
authors.forename: Weiyou
authors.initials: W
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, , Haidian District, Beijing, 100083 China.
authors.forename: Junping
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, , Haidian District, Beijing, 100083 China.
authors.forename: Fang
authors.initials: F
authors.lastname: Yuan
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, , Haidian District, Beijing, 100083 China.
authors.forename: Yanxiang
authors.initials: Y
authors.lastname: Gao
keywords: Antioxidant activity; Marigold flower residues; On-line HPLC-ABTS·+; Phenolic compounds; Subcritical water extraction (SWE)