摘要：Extraction of phytochemical compounds (such as β-carotene, linoleic acids, carrageenan, and polyphenols) from algaeEucheuma cottoniiandGracilaria spwith supercritical CO2followed by subcritical water has been investigated. Supercritical CO2extraction was carried out at pressure of 25 MPa, temperature of 60°C, CO2flowrate of 15 ml/min, and ethanol flowrate of 0.25 ml/min. To determine the content of carotenoids and linoleic acids, the extracted compounds were analyzed using a spectrophotometer UV-Vis. The residue of algae starting material was subsequently extracted by subcritical water at pressures of 3, 5, and 7 MPa, and temperatures of 120, 140, 160, and 180 °C. Carrageenan extracted by subcritical water was analyzed using Fourier Transform Infra Red (FTIR), while the total phenolic compound was analyzed with UV-vis spectrophotometer. Moreover, the antioxidant efficiency of extract was also examined by DPPH assay method. Based on the analytical result, β-carotene and linoleic acid content inEucheuma cottoniiwere 209.91 and 321.025 μg/g sample, respectively. While β-carotene and linoleic acid content inGracilaria spwere 219.99 and 286.52 μg/g sample, respectively. The optimum condition of subcritical water extraction was at 180°C and 7 MPa. At this condition, the highest TPC content in the extract fromEucheuma cottoniiandGracilaria spwere 18.51 mg GAE/g sample and 22.47 mg GAE/g sample, respectively; while the highest yield of carrageenan extracted fromEucheuma cottoniiandGracilaria spwere 61.33 and 65.54 g/100 g dried algae, respectively. At the same condition, the antioxidant efficiency was 0.513 min-1forEucheuma cottoniiand 0,277 min-1forGracilaria sp. Based on the results the extraction method effectively separated non-polar and polar compounds, then increased the antioxidant efficiency of extract.
