Abstract This study evaluated the oil content obtained from andiroba seeds by pressurized n-propane at different conditions of temperature (25, 35, and 45 °C) and pressure (40, 60, and 80 bar), and conventional extraction technique using n-hexane as the solvent. Kinetic extraction curves were fitted using Sovová’s mathematical model. The chemical characterization of the oil was reported as well as the protein content in the extraction by-product. Pressurized extractions conducted at 25 °C provided the highest oil recovery (~45 wt%) from the seeds. The increase in pressure at 25 ºC favored obtaining oil with higher Stigmasterol contents, however, the Squalene content was higher in the oil obtained at 40 bar. The oils with the highest concentration phenolic compounds and antioxidant activity were obtained at 80 bar. Extraction with n-propane provided oils with higher levels of phenolic compounds, however, with antioxidant activity similar to conventional extraction. For all evaluated extractions, the product showed a predominance of oleic and palmitic acids, with similar values of oxidative stability. The extraction of the by-product with the highest soluble protein content was obtained under mild processing conditions (25 °C and 40 bar) with n-propane. npropane n propane 25, 35 4 C 40, (40 60 8 bar, bar , nhexane hexane solvent Sovovás Sovová s model byproduct. byproduct product. 2 ~45 (~4 wt% wt contents however acids stability (2 npropane. propane. 3 (4 6 ~4 (~ ( ~

Existem fatores nutricionais e dietéticos, como a ligação comprovada entre o excesso do colesterol no sangue e doenças cardíacas e alguns tipos de câncer, que justificam as pesquisas de desenvolvimento de tecnologias que reduzam o teor de colesterol dos alimentos. Estudos anteriores demonstraram a viabilidade da utilização de CO2 e etano na remoção do colesterol do óleo de manteiga. O colesterol apresenta maior solubilidade no etano que no CO2; porém, o etano é de maior custo. A utilização de misturas CO2/etano, portanto, apresenta-se como uma alternativa atraente, devido à redução dos custos energéticos e econômicos. Utilizando um aparelho experimental de extração a altas pressões, que permite um controle independente de temperatura e pressão, foram determinadas as solubilidades do colesterol em misturas de CO2/etano supercríticos com 8%, 16%, 34%, 76%, 88% e 96,5% de etano, a 328,1 K e pressões de 120 a 190 bar. Os resultados experimentais mostram um aumento da solubilidade com a pressão e a composição de etano na mistura. Para correlacionar os dados experimentais foi usado um modelo termodinâmico que utiliza a equação de Peng-Robinson com as regras de mistura de van der Waals e a regra que considera o parâmetro de interação dependente da densidade, resultando numa equação de quarta ordem. A regra de mistura dependente da densidade se mostrou eficaz na correlação dos dados experimentais.

There are nutritional and dietary factors, such as those linking excess blood cholesterol to heart diseases and cancer, that justify the development of a technology for the reduction of cholesterol levels in consumed meals. Previous studies have demonstrated the viability of using CO2 for the removal of cholesterol from butter oil. Cholesterol has higher solubility in ethane than in CO2. The use of CO2/ethane mixtures, therefore, presents as an attractive alternative, as a compromise between the higher ethane cost better cholesterol removal efficiency obtained and envolved. Using a high pressure experimental extraction apparatus that allows the independent control of temperature and pressure, cholesterol solubilities in supercritical CO2/ethane mixtures with 8%, 16%, 34%, 76%, 88% e 96,5% of ethane were determined at 328,1 K and pressures from 120 to 190 bar. Experimental results show an increase in solubility with pressure and a composition of ethane in the mixture. Experimental data were correlated with a thermodynamics model that uses Peng-Robinson equation with two different mixing rules: the normally used van der Waals and a rule that considers the interaction parameter density dependent resulting in a quartic equation of state. The density dependent mixing rule reveal more successful in the correlation of experimental data.

A descafeinação do café canephora é vantajosa tanto para a obtenção da cafeína quanto para valorização desta espécie. A cafeína, subproduto da descafeinação, atua como estimulante e diurético no organismo e é usado pelas indústrias de bebidas de refrigerante e farmacêutica. Existem patentes industriais aplicando CO2 supercrítico na extração da cafeína do café. Porém pouco é divulgado sobre a extração da trigonelina (alcalóide importante na formação da vitamina‘ niacina’), que atua no sistema nervoso central, na secreção da bile e no intestino. O objetivo deste trabalho foi levantar subsídios experimentais e teóricos para a extração de alcalóides dos grãos de café canephora, variedade robusta, usando CO2 supercrítico. Os dados foram obtidos num aparelho de extração a altas pressões onde as variáveis termodinâmicas são independentemente controladas. Os alcalóides foram analisados por Cromatografia Liquida de Alta Eficiência (CLAE). As solubilidades da cafeína pura e a obtida dos grãos de café no CO2 supercrítico foram determinadas a 313, 323 e 343 K, de 9,5 a 23,5 MPa. Os resultados revelam a existência de um comportamento retrógrado para a solubilidade da cafeína pura e a obtida dos grãos de café; também mostram a seletividade do CO2 supercrítico pela cafeína quando comparada a trigonelina. A modelagem termodinâmica do equilíbrio sólido-fluido usando uma equação de estado de quarta ordem correlacionou satisfatoriamente as solubilidades da cafeína pura no solvente supercrítico.

Caffeine, aby-product of coffee decaffeination by-product, acts as a stimulant and diuretic in the human organism. Most of the caffeine is used in the cola soft drink and pharmaceutical industries. Supercritical CO2 has long been used to decaffeinate coffee beans. However, little is known about the extraction of other alkaloids such as trigonelline. This alkaloid and the products generated by its thermal degradation (nicotinic acid - the vitamin niacin) have received a lot of attention because of their nutritional importance. Trigonelline acts mainly on the nervous central system, the secretion bile and the intestine. The main objective of this work was to obtain experimental data on the extraction of the alkaloids caffeine and trigonelline from canephora (Robusta) coffee beans using supercritical CO2. The decaffeination of this coffee can be economically attractive to obtain caffeine and to upgrade the value of this variety of coffee. New data on the continuouos fractionation of Brazilian Robusta coffee beans using supercritical CO2 at 313, 323 and 343 K and pressures ranging from 9,5 to 23,5 MPa for the extraction and separation of caffeine and trigonelline are presented. Caffeine and trigonelline in the extracted mixture were analyzed using HPLC. A thermodynamic model that uses a quartic equation of state was successfully employed to correlate the solubility behavior of pure caffeine in supercritical CO2.