Recovery of antioxidant and antiproliferative compounds from watercress using pressurized fluid extraction. Issue 37 (24th March 2016)

• Record Type: Journal Article
• Authors: Rodrigues, Liliana; Silva, Inês; Poejo, Joana; Serra, Ana Teresa; Matias, Ana A.; Simplício, Ana Luísa; Bronze, Maria R.; Duarte, Catarina M. M.
• Is Part Of: RSC advances. Volume 6:Issue 37(2016)
• Page Start: 30905
• Page End: 30918
• Publication Date: 2016-03-24
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra28068k
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : The potential of pressurized fluid technology to isolate bioactive antioxidant and antiproliferative compounds from watercress was studied. Abstract : In this work, pressurized fluid extraction was explored to recover isothiocyanates (ITCs) and phenolic compounds from watercress. Pretreatment of the raw material was studied, using different conditions of temperature (25 °C; 35 °C), pressure ( P atm ; 25 MPa), incubation time (0; 30; 60; 120 min) and moisture content (125; 250; 900% of water, dry basis), aiming at promoting the enzymatic hydrolysis of glucosinolates in ITCs. Extractions of ITCs were performed with supercritical CO2, and different mixtures of CO2 : ethanol (0–50, % w/w) were applied to obtain phenolic-enriched ITCs extracts. Extractions were performed at 35 °C and 25 MPa for 2 h and extracts analyzed concerning total ITCs, phenethyl isothiocyanate (PEITC) content, phenolic composition, antioxidant capacity (using ORAC, HORAC and HOSC assays) and antiproliferative effect in a human colorectal cancer cell line (HT-29). Results showed that supercritical CO2 was highly selective in isolating ITCs from watercress (up to 31.7 ± 1.6 μmol ITC per g). When mixtures of CO2 : ethanol were used, extraction of phenolics (up to 10.1 ± 0.8 mg GAE per g) and antioxidants (up to 204.4 ± 21.5 μmol TE per g concerning ORAC, 70.8 ± 10.7 μmol CAE per g for HORAC and 189.5 ± 22.9 μmol TE per g for HOSC), was promoted. PEITC was the main compound responsible for the inhibition of cancer cell growth of all extracts (EC5024 h = 27.8 ± 1.9 μM PEITC). However, extracts obtained by supercritical CO2 extraction after a 30 minute incubation period with CO2 and with CO2 : ethanol mixtures (80 : 20 and 60 : 40, % w/w) were revealed to be effective in isolating other bioactive compounds that enhanced the antiproliferative response of extracts (EC5024 h values of 23.1 ± 0.9; 20.7 ± 1.9 and 19.8 ± 0.7 μM PEITC, respectively).