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.

Background: From January 2000 to June 2002, the first Chilean registry of unstable angina was carried out, with the participation of 15 hospitals. Aim: To report the clinical and demographic features of 600 patients with unstable angina, their risk profile and prognosis. Material and methods: The inclusion criteria for this prospective registry were a history of recent onset of chest pain (<48 hours) or a change in the character of previous angina, associated to ischemic electrocardiographic changes and/or positive markers of myocardial damage. Results: Mean age of the patients was 65 years and 37% were women. Among coronary risk factors, 63% had hypertension, 27% had diabetes, 52% had dyslipidemia, 31% smoked and 21% had a family history of atherosclerosis. On admission 94% of patients had chest pain, associated to ST segment depression in 44%, negative T waves in 28% and positive markers of myocardial damage in 30%. Fifty seven percent received intravenous nitroglycerin, 47% received oral nitrates, 69% beta blockers and 15%, calcium antagonists. Antithrombotic therapy included aspirin in 96%, heparin in 74%, ticlodipine or clopidogrel in 19% and IIb/IIIa inhibitors in 12%. A coronary angiogram was performed in 52%, angioplasty in 25% and coronary bypass surgery in 13%. Hospital mortality was 2.6%. The incidence of new ischemic events was: myocardial infarction in 2.8% recurrent ischemia in 9.5% and refractory ischemia in 2%. The incidence of adverse events increased according to a higher risk profile. Conclusions: The demographic and clinical features, treatment and mortality of these patients are similar to those reported in international registries, with a low mortality rate (Rev Méd Chile 2004; 132: 135-43)

The goal of this work was to find a process to extract and separate carotene from natural sources using supercritical carbon dioxide. A high pressure extraction process was compared with a combined extraction-adsorption process. The experiments were performed with a pilot plant which can be operated up to 50 MPa and 100ºC. A technique using an on-line photometer, was used to estimate the concentration of carotenoids in the fluid phase, to monitor the different steps of the process. During the extraction of paprika powder, a time fractionation of pigments was observed: a low concentration fraction of free carotenoids at the beginning of the process and an enriched esterified carotenoid fraction at the end. With the combined extraction-adsorption process, using silica gel as adsorbent, a selective adsorption occurred. Red pigments (mainly esterified carotenoid) were adsorbed but the yellow ones (mainly free carotenoid) remained in supercritical phase which were collected in a separation step at lower pressure.

Supercritical CO2 extraction has shown great potential in separating vegetable oils as well as removing undesirable oil residuals from natural products. The influence of process parameters, such as pressure, temperature, mass flow and particle size, on the mass transfer kinetics of different natural products has been studied by many authors. However, few publications have focused on specific features of the raw material (moisture, mechanical pretreatment, bed compressibility, etc.), which could play an important role, particularly in the scale-up of extraction processes. A review of the influence of both process parameters and specific features of the material on oilseed extraction is given in Eggers (1996). Mechanical pretreatment has been commonly used in order to facilitate mass transfer from the material into the supercritical fluid. However, small particle sizes, especially when combined with high moisture contents, may lead to inefficient extraction results. This paper focuses on the problems that appear during scale-up in processes on a lab to pilot or industrial plant scale related to the pretreatment of material, the control of initial water content and vessel shape. Two applications were studied: deoiling of wheat gluten with supercritical carbon dioxide to produce a totally oil-free (< 0.1 % oil) powder (wheat gluten) and the extraction of oil from rose hip seeds. Different ways of pretreating the feed material were successfully tested in order to develop an industrial-scale gluten deoiling process. The influence of shape and size of the fixed bed on the extraction results was also studied. In the case of rose hip seeds, the present work discusses the influence of pretreatment of the seeds prior to the extraction process on extraction kinetics.