A. Monteiro

Determination of the solubility of extracts from vegetable raw material in pressurized CO2: a pseudo-ternary mixture formed by cellulosic structure+solute+solvent

This paper discusses the application of the dynamic method to measure the solubility in pseudo-ternary systems formed by vegetable raw materials (cellulosic structure+solute) and CO2. For aromatic, medicinal, and spice plants, the soluble portion of the solid is formed of essential oils, oleoresins, pigments, and various substances from several other classes of organic compounds. The experimental data were measured in two independent laboratories, using three experimental set-ups, and three vegetable species: clove buds, eucalyptus, and ginger. The solubility for the system clove buds/CO2 varied from 0.220 to 0.277 kg-extract/kg-CO2 for the isotherm of 288.15 K. The ginger extract solubility varied from 2.01×10−3 to 7.20×10−3 kg-extract/kg-CO2 for pressures of 100–300 bar, and temperatures of 298.15–313.15 K. The eucalyptus solubility for the isobar of 66.7 bar varied from 3.95×10−3 to 4.07×10−3 kg-extract/kg-CO2.

Extraction of the soluble material from the shells of the bacuri fruit (Platonia insignis Mart) with pressurized CO2 and other solvents

The extraction of soluble material from bacuri shells has been studied. The effects of pressure, temperature, particle size, static period and flow time were investigated for extraction with liquid carbon dioxide (LCO2). The yield and the composition of the extracts obtained with LCO2 were compared with those for extracts obtained with other techniques, such as LCO2 plus ethanol (LCO2-EtOH), supercritical CO2 (SCO2), steam distillation (SD), cold ethanol (C-EtOH), and Soxhlet extraction with ethanol (EtOH-So). The LCO2 and LCO2-EtOH extractions were performed at pressures of 63–70 bar, and temperatures of 16–21°C. The constituents isolated from the bacuri shell extracts were predominantly free fatty acids: palmitic, oleic, linoleic, α-linolenic, and stearic acids. In addition to these fatty acids, the LCO2-EtOH extracts contained caprylic and myristic acids, alcohols (linalool and 3,7-dimethyl oct-1-en-3,7-diol), and the phenol ether eugenol. The SCO2 extraction was performed at 200 bar and 50°C. The SCO2 extract had a composition similar to the LCO2 extract, but the α-linolenic acid was not present, although hydrocarbons such as β-bisabolene, and alcohols such as 3,7-dimethyl-1-octen-3,7-diol, linalool, and α-terpineol were identified. In the extract obtained by SD, only hydrocarbons (methyl benzene and 2-methyl heptane), alcohols (linalool and α-terpineol), and oxides (cis-linalool oxide and trans-linalool oxide) were identified. In the C-EtOH and EtOH-So extracts only trimethyl citrate was identified.

COMPARISON OF GINGER (Zingiber officiale Roscoe) OLEORESIN OBTAINED WITH ETHANOL AND ISOPROPANOL WITH THAT OBTAINED WITH PRESSURIZED CO2

O gengibre (Zingiber officinale Roscoe) pertence a familia Zingiberacea. E uma especiaria de grande importância comercial. Neste trabalho realizou-se extracoes da oleoresina de gengibre com etanol, isopropanol e dioxido de carbono liquido e comparou-se a composicao quimica de cada um dos extratos. A oleoresina obtida tem componentes das classes dos monoterpenos e sesquiterpenos em todas as amostras. Acidos carboxilicos foram encontrados nos extratos obtidos com solvente orgânico, quando o tempo de extracao foi de 2 horas. Os componentes que dao a caracteristica pungente a oleoresina, os gingerois, foram detectados nas amostras obtidas com solvente orgânico, quando o tempo de extracao foi de 6 horas e, nas amostras obtidas com CO2 liquido, com 2 horas de extracao.