title: Central composite design for the optimization of supercritical carbon dioxide fluid extraction of fatty acids from Borago officinalis L. flower.
abstract: In the present study, fatty acids and essential oils of the flower of borage (Borago officinalis L.) were obtained by supercritical carbon dioxide fluid extraction under different conditions. The extracts obtained were compared to oils of borage flower oil isolated by hydrodistillation. The obtained oils were analyzed by gas chromatography mass spectrometry. The compounds were identified according to their retention indices and mass spectra. The experimental parameters of supercritical fluid extraction (SFE) were optimized using a central composite design after a full factorial experimental design. Extraction yields based on SFE varied in the range of 0.02% to 1.96% (w/w), and the oil yield based on the hydrodistillation was 0.05% (v/w). The optimum conditions of SFE were obtained at a pressure of 350 atm, a temperature of 65 °C, a methanol modifier volume of 100 μL, and static and dynamic extraction time of 10 min. Main components of the extracts under optimum SFE conditions were palmitic acid, linoleic acid, γ-linolenic acid, and oleic acid. The results indicated that by using the suitable extraction conditions, SFE is more effective than the conventional hydrodistillation method in the extraction of fatty acids and the preservation of its quality.
  
  
  CONCLUSIONS
  SFE is a good technique for the extraction of oils from plants. The extraction yields by SFE are more than the conventional method. SFE is used on a large scale for production of essential oils and pharmaceutical products from plants.
authors.affiliation: Dept. of Chemistry, Faculty of Science, Shahid Beheshti Univ., GC, Tehran, Iran.
authors.forename: Negin Fasih
authors.initials: NF
authors.lastname: Ramandi
authors.forename: Nahid Mashkouri
authors.initials: NM
authors.lastname: Najafi
authors.forename: Farhad
authors.initials: F
authors.lastname: Raofie
authors.forename: Ensieh
authors.initials: E
authors.lastname: Ghasemi
mesh_terms: D029683:Borago / Q000737:chemistry*; D002245:Carbon Dioxide / Q000378:metabolism; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D005227:Fatty Acids / Q000032:analysis / Q000302:isolation & purification*; D035264:Flowers / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D019787:Linoleic Acid / Q000032:analysis; D008962:Models, Theoretical; D009822:Oils, Volatile / Q000032:analysis*; D019301:Oleic Acid / Q000032:analysis; D019308:Palmitic Acid / Q000032:analysis; D010936:Plant Extracts / Q000032:analysis*; D011312:Pressure; D013696:Temperature; D017965:gamma-Linolenic Acid / Q000032:analysis
chemical_list: D005227:Fatty Acids; D009822:Oils, Volatile; D010936:Plant Extracts; D002245:Carbon Dioxide; D019301:Oleic Acid; D019308:Palmitic Acid; D017965:gamma-Linolenic Acid; D019787:Linoleic Acid