Different extraction processes were employed to extract the polyphenolic compounds from pitanga (Eugenia uniflora L.) leaves: a one-step process using water, ethanol or supercritical CO2 as solvents, and a two-step process using supercritical CO2 followed by either water or ethanol. The total polyphenolic compounds, total flavonoids and antioxidant activity were determined in all the extracts obtained. The process performance was evaluated with respect to three variables: global extraction yield, concentration and yield of both polyphenols and flavonoids in the extracts. For the one-step extraction, the results showed that the extraction yield increased with solvent polarity. For the two-step process, the results suggested that water was more efficient in extracting the phenolic compounds from E. uniflora when the matrix was previously extracted with scCO2. With respect to the antioxidant activity, the ethanolic extracts obtained from both processes, using either the DPPH radical scavenging method or the β-carotene bleaching method, presented high antioxidant activities. © 2010 Elsevier B.V. All rights reserved.5539981006Auricchio, M.T., Bacchi, E.M., Folhas de Eugenia uniflora L. (pitanga): Revisão (2003) Revista Instituto Adolfo Lutz, 62, pp. 55-61Peixoto, C.A., (2008) Supercritical Extraction of Eugenia Uniflora L. Leaves, , Ph.D. Thesis University of Campinas, Campinas, SP, BrazilConsolini, A.E., Sarubbio, M.G., Pharmacological effects of Eugenia uniflora (Myrtaceae) aqueous crude extract on rat's heart (2002) Journal of Ethnopharmacology, 81, pp. 57-63Díaz-Reinoso, B., Moure, A., Dominguez, H., Parajó, J.C., Supercritical CO2 extraction and purification of compounds with antioxidant activity (2006) Journal of Agricultural and Food Chemistry, 54, pp. 2441-2469Mukhopadhyay, M., (2000) Natural Extracts Using Supercritical Carbon Dioxide, , CRC Press Boca RatonMuchuweti, M., Mupure, L., Ndhlala, A., Murenje, T., Benhura, M.A.N., Screening of antioxidant and radical activity of Vigna ungiculata, Bidens pilosa and Cleome gynandra (2007) American Journal of Food Technology, 2, pp. 161-168Ribeiro, M.A., Bernardo-Gil, M.G., Esquível, M.M., Melissa officinalis, L.: Study of antioxidant activity in supercritical residues (2001) The Journal of Supercritical Fluids, 21, pp. 51-60Vatai, T., Škerget, M., Knez, Ž., Extraction of phenolic compounds from elder berry and different grape marc varieties using organic solvents and/or supercritical carbon dioxide (2009) Journal of Food Engineering, 90, pp. 246-254A, E.A.S., (1997) Standards, Method of Determining and Expressing Fineness of Feed Materials by Sieving, , ASAE S319.3Uquiche, E., Del Valle, J.M., Ortiz, J., Supercritical carbon dioxide extraction of red pepper (Capsicum annuum L.) oleoresin (2004) Journal of Food Engineering, 65, pp. 55-66Rahman, M.S., Perera, C.O., Dong Chen, X., Driscoll, R.H., Lal Potluri, P., Density, shrinkage and porosity of calamari mantle meat during air drying in a cabinet dryer as a function of water content (1996) Journal of Food Engineering, 30, pp. 135-145Cseke, L.J., Setzer, W.N., Vogler, B., Kirakosyan, A., Kaufman, P.B., Traditional, analytical and preparative separations of natural products (2006) Natural Products from Plants, pp. 263-318Singleton, V.L., Orthofer, R., Lamuela-Raventos, R.M., Analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent (1999) Methods in Enzymology, 299, pp. 152-178Zhishen, J., Mengcheng, T., Jianming, W., The determination of flavonoids contents in mulberry and their scavenging effects on superoxide radicals (1999) Food Chemistry, 64, pp. 555-559Adams, R.P., (1995) Identification of Essential Oil Components by Gas Chromatography/Mass Spectrometry, , Allured Publishing CorporationMensor, L.L., Menezes, F.S., Leitão, G.G., Reis, A.S., Dos Santos, T.C., Coube, C.S., Leitão, S.G., Screening of Brazilian plant extracts for antioxidant activity by the use of DPPH free radical method (2001) Phytotherapy Research, 15, pp. 127-130Marco, J.G., A rapid determination for evaluation of antioxidants (1968) Journal of the American Oil Chemists' Society, 45, pp. 594-598Miller, H.E., A simplified method for the evaluation of antioxidant (1971) Journal of the [X] American Oil Chemists Society, 48, p. 91Tan, C.S., Liou, D.C., Modeling of desorption at supercritical conditions (1989) AIChE Journal, 35, pp. 1029-1031Naik, S.N., Lentz, H., Maheshawari, R.C., Extraction of perfumes and flavors from plant materials with liquid carbon dioxide under liquid-vapor equilibrium conditions (1989) Fluid Phase Equilibria, 49, pp. 115-126Sovová, H., Aleksovski, S.A., Bocevska, M., Stateva, R.P., Supercritical fluid extraction of essential oils results of joint research (2006) Chemical Industry & Chemical Engineering Quarterly, 12, pp. 168-174Silva, D.C.M.N., Bresciani, L.F.V., Dalagnol, R.L., Danielski, L., Yunes, R.A., Ferreira, S.R.S., Supercritical fluid extraction of carqueja (Baccharis trimera) oil: Process parameters and composition profiles (2009) Food and Bioproducts Processing, 87, pp. 317-326Sousa, E.M.B.D., Martinez, J., Chiavone-Filho, O., Rosa, P.T.V., Domingos, T., Meireles, M.A.A., Extraction of volatile oil from Croton zehntneri Pax et Hoff with pressurized CO2: Solubility, composition and kinetics (2005) Journal of Food Engineering, 69, pp. 325-333Aleksovski, S.A., Sovova, H., Supercritical CO2 extraction of Salvia officinalis L. (2007) The Journal of Supercritical Fluids, 40, pp. 239-245Peixoto, C.A., Oliveira, A.L., Cabral, F.A., Composition of supercritical carbon dioxide extracts of pitanga (Eugenia Uniflora L.) leaves (2010) Journal of Food Process Engineering, 33, pp. 848-860Melo, R.M., Corrêa, V.F.S., Amorim, A.C., Miranda, A.L., Rezende, C., Identification of impact aroma compounds in Eugenia uniflora L. (Brazilian Pitanga) leaf essential oil (2007) Journal of Brazilian Chemical Society, 18, pp. 179-183Galhiane, M.S., Rissato, S.R., Chierice, G.O., Almeida, M.V., Silva, L.C., Influence of different extraction methods on the yield and linalool content of the extracts of Eugenia uniflora L. (2006) Talanta, 70, pp. 286-292Costa, D.P., Santos, S.C., Seraphin, J.C., Ferri, P.H., Seasonal variability of essential oils of Eugenia uniflora Leaves (2009) Journal of the Brazilian Chemical Society, 20, pp. 1287-1293Weyerstahl, P., Marschall-Weyerstahl, H., Christiansen, C., Oguntimein, B.O., Adeoye, A.O., Volatile constituents of Eugenia uniflora leaf oil (1988) Planta Medica, 54, pp. 546-549Morais, S.M., Craveiro, A.A., MacHado, M.I.L., Alencar, J.W., Matos, J.A., Volatiles constituents of Eugenia uniflora leaf oil from northeastern Brazil (1996) Journal of Essential Oil Research, 8, pp. 449-451Ogunwande, I.A., Olawore, N.O., Ekundayo, O., Walker, T.M., Schmidt, J.M., Setzer, W.N., Studies on the essential oils composition, antibacterial and cytotoxicity of Eugenia uniflora L (2005) The International Journal of Aromatherapy, 1, pp. 147-152Benner, B.A., Summarizing the effectiveness of supercritical fluid extraction of polycyclic aromatic hydrocarbons from natural matrix environmental samples (1998) Analytical Chemistry, 70, pp. 4594-4601Grigonis, D., Venskutonis, P.R., Sivik, B., Sandahl, M., Eskilsson, C.S., Comparison of different extraction techniques for isolation of antioxidants from sweet grass (Hierochloë odorata) (2005) The Journal of Supercritical Fluids, 33, pp. 223-233Stamenic, M., Zizovic, I., Eggers, R., Jaeger, P., Heinrich, H., Roj, E., Ivanovic, J., Skala, D., Swelling of plant material in supercritical carbon dioxide (2010) The Journal of Supercritical Fluids, 52, pp. 125-133Turkmen, N., Sari, F., Velioglu, Y.S., Effects of extraction solvents on concentration and antioxidant activity of black and black mate tea polyphenols determined by ferrous tartrate and Folin-Ciocalteu methods (2006) Food Chemistry, 99, pp. 835-841Moon, J.K., Shibamoto, T., Antioxidant assays for plant and food components (2009) Journal of Agricultural and Food Chemistry, 57, pp. 1655-1666Velázquez, E., Tournier, H.A., Mordujovich De Buschiazzo, P., Saavedra, G., Schinella, G.R., Antioxidant activity of Paraguayan plant extracts (2003) Fitoterapia, 74, pp. 91-97Zarena, A.S., Sankar, K.U., A study of antioxidant properties from Garcinia mangostana L. pericarp extract (2009) ACTA Scientiarum Polonorum, Technologia Alimentaria, 8, pp. 23-34De Campos, L.M.A.S., Leimann, F.V., Pedrosa, R.C., Ferreira, S.R.S., Free radical scavenging of grape pomace extracts from cabernet sauvingnon (Vitis vinifera) (2008) Bioresource Technology, 99, pp. 8413-8421Hinneburg, I., Dorman, H.J.D., Hiltunen, R., Antioxidant activities of extracts from selected culinary herbs and spices (2006) Food Chemistry, 97, pp. 122-129Nickavar, B., Kamalinejad, M., Izadpanah, H., In vitro free radical scavenging activity of five salvia species (2007) Pakistan Journal of Pharmaceutical Sciences, 20, pp. 291-294Kelen, M., Tepe, Z., Screening of antioxidative properties and total phenolic compounds (2007) Pakistan Journal of Biological Sciences, 10, pp. 403-408Wu, N., Fu, K., Fu, Y.J., Zu, Y.G., Chang, F.R., Chen, Y.H., Liu, X.L., Gu, C.B., Antioxidant activities of extracts and main components of pigeonpea [Cajanus cajan (L.) Millsp.] leaves (2009) Molecules, 14, pp. 1032-1043Cavar, S., Maksimovic, M., Solic, M.E., Jerkovic-Mujkic, A., Besta, R., Chemical composition and antioxidant and antimicrobial activity of two Satureja essential oils (2008) Food Chemistry, 111, pp. 648-653Porter, W., Black, E.D., Drolet, A.M., Use of polyamide oxidative fluorescence test on lipid emulsions: Contrast on relative effectiveness of antioxidants in bulk versus dispersed systems (1989) Journal of Agricultural and Food Chemistry, 37, pp. 615-624Frankel, E.N., Huang, S.W., Kanner, J., German, J.B., Interfacial phenomena in the evaluation of antioxidants: Bulk oils vs. emulsions (1994) Journal of Agricultural and Food Chemistry, 42, pp. 1054-1059Eklund, P.C., Lngvik, O.K., Wärn, J.P., Salmi, T.O., Willför, S.M., Sjöholm, R.E., Chemical studies on antioxidant mechanisms and free radical scavenging properties of lignans (2005) Organic and Biomolecular Chemistry, 3, pp. 3336-3347Koleva, I.I., Niederländer, H.A.G., Van Beek, T.A., An on-line HPLC method for detection of radical scavenging compounds in complex mixtures (2000) Analytical Chemistry, 7, pp. 2323-2328Pouvreau, J.B., Moranais, M., Taran, F., Rosa, P., Dufossé, L., Guérard, F., Pin, S., Pondaven, P., Antioxidant and free radical scavenging properties of Marennine, a blue-green polyphenolic pigment from the Diatom Haslea ostrearia (Gaillon/Bory) Simonsen responsible for the natural greening of cultured oysters (2008) Journal of Agricultural and Food Chemistry, 56, pp. 6278-6286