Supercritical CO2 extraction of fennel seeds has been performed in two steps; the first step was performed at 90 bar and 50 °C to obtain the selective extraction of essential oil. The second one was performed at 200 bar and 40 °C and allowed the extraction of vegetable oil. The experiments were performed using the fractional separation of the extracts using three different CO2 flow rates (0.5, 1.0, and 1.5 kg/h). On the basis of the extraction results and of the analysis of scanning electron microscopy (SEM) images of the vegetable matter, mathematical models of the two extraction processes have been proposed. The extraction of fennel vegetable oil has been modeled using a model based on differential mass balances and on the concept of broken and intact cells as evidenced by SEM. Only one adjustable parameter has been used:  the internal mass-transfer coefficient k t. A fairly good fitting of the experimental data was obtained by setting k t = 8 × 10-8 m/s. The fennel essential oil extraction process was modeled as desorption from the vegetable matter plus a small mass-transfer resistance. The same internal mass-transfer coefficient value used for vegetable oil extraction allowed a fairly good fitting of the essential oil extraction data.

Aims:  The antifungal effect of Pimpinella anisum (anise), Pëumus boldus (boldus), Mentha piperita (peppermint), Origanum vulgare (oregano) and Minthosthachys verticillata (peperina) essential oils against Aspergillus section Flavi (two isolates of Aspergillus parasiticus and two isolates of Aspergillus flavus) was evaluated in maize meal extract agar at 0·982 and 0·955 water activities, at 25°C. Methods and Results:  The percentage of germination, germ‐tube elongation rate, growth rate and aflatoxin B1 (AFB1) accumulation at different essential oils concentrations were evaluated. Anise and boldus essential oils were the most inhibitory at 500 mg kg−1 to all growth parameters of the fungus. These essential oils inhibited the percentage of germination, germ‐tube elongation rate and fungal growth. AFB1 accumulation was completely inhibited by anise, boldus and oregano essential oils. Peperina and peppermint essential oils inhibited AFB1 production by 85–90% in all concentrations assayed. Conclusions:  Anise and boldus essential oils could be considered as effective fungitoxicans for Aspergillus section flavi. Significance and Impact of the Study:  Our results suggest that these phytochemical compounds could be used alone or in conjunction with other substances to control the presence of aflatoxigenic fungi in stored maize.

-Wheat germ oil was obtained by mechanical pressing using a small-scale screw press and by supercritical extraction in a pilot plant. With this last method, different pressures and temperatures were tested and the tocopherol concentration in the extract was monitored during extraction. Then supercritical extracted oil as well as commercial pressed oil were deacidified in a countercurrent column using supercritical carbon dioxide as solvent under different operating conditions. Samples of extract, refined oil and feed oil were analyzed for free fatty acids (FFA) and tocopherol contents. The results show that oil with a higher tocopherol content can be obtained by supercritical extraction-fractionation and that FFA can be effectively removed by countercurrent rectification while the tocopherol content is only slightly reduced.

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