Desarrollo económico y cambio demográfico: El caso de Chile

La transición demográfica chilena se produjo en menos de 60 años, casi triplicando su población desde 1950 a 2014. En 50 años se produjo un gran descenso de la fecundidad, con gran influencia en la caída del crecimiento de la población del país. Tiene mucha importancia la reducción de las tasas de la mortalidad, aunque se ha visto modificada su tendencia debido al envejecimiento poblacional. Chile se encuentra en una etapa de la transición avanzada y está inmerso en un proceso de envejecimiento. Las tendencias en Chile en el período comprendido entre 2000-2050, hacen prever que los cambios por llegar serán mucho menores que los ocurridos en los cincuenta años previos. La población aumentará con ritmos de crecimiento menores, la fecundidad en el país continuará en descenso. Respecto a la mortalidad, ésta seguirá reduciéndose, aumentando consigo la esperanza de vida al nacer debido al proceso de envejecimientoDepartamento de Sociología y Trabajo SocialGrado en Economí

Microencapsulation by spray drying of omega-3 lipids extracted from oilseeds and microalgae: Effect on polyunsaturated fatty acid composition

In this work, microencapsulation of omega-3 lipids from sustainable sources, including oilseeds such as Salvia hispanica L., Echium plantagineum L. and Camelina sativa L., microalgal lipids (from Nannochloropsis gaditana) and enzymatically produced fatty acid ethyl esters (FAEEs), was successfully done by spray drying and their outcomes studied. Previous to microencapsulation process, lipid extracts from new omega-3 sources (chia, camelina and echium oilseeds and wet microalgal biomass of Nannochloropsis) were produced using Pressurized Liquid Extraction. The best microencapsulation efficiency was achieved for chia FAEEs (76.9%), while the lowest was obtained for camelina oil (58.8%) and Nannochloropsis gaditana lipids (57.0%) microcapsules, which also showed low emulsion stability. Analysis by GC-MS showed that microencapsulation process did not negatively affect omega-3 fatty acid profile of microencapsulated extracts. The percentage of omega-3 in each used lipid was similar before and after spray drying (no significant differences at 5% level). Under the optimal conditions, produced microcapsules ranged from 1.5 to 30 μm and showed spherical shape and smooth surface without cracks. Thus, the proposed method provides an original approach to produce omega-3 microencapsulated lipid extracts from different nature, with high microencapsulation efficiency and payload, for potential applications in the development of foods enriched in omega-3 fatty acidsAuthors thank the Spanish Ministry of Education, Culture and Sport for the pre-doctoral contract (FPU 2013–01796) granted to Natalia Castejón. The authors gratefully acknowledge the financial support from Comunidad de Madrid provided through project ALGATEC-CM (P2018/BAA-4532), co-financed by the European Social Fund. Authors thank Camelina Company (Spain) for kindly provide camelina seeds, Technology Crops Int. (UK) for providing echium seeds and Novozymes (Denmark) for donating commercial lipases. The assistance of Javier Agundez (ICP–CSIC, Spain) for getting SEM images is also acknowledged. Authors also thank AlgaEnergy S.A. (Spain) and Dr. Federico Witt for kindly provide Nannochloropsis gaditana biomas

Kinetic study of pilot-scale supercritical CO2 extraction of rosemary (Rosmarinus officinalis) leaves

NOTICE: This is the author’s version of a work that was accepted for publication in Journal of Supercritical Fluids. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Supercritical Fluids, 55 (2011). http://dx.doi.org/10.1016/j.supflu.2010.09.030Rosmarinus officinalis (rosemary) extracts were obtained in a supercritical pilot-scale plant. Based on experimental information available in the literature for analytical or low-scale processes, extraction temperature and pressure were selected to be 313 K and 30 MPa. At these extraction conditions, the kinetic behavior of the pilot-scale overall extraction curve were determined with respect to yield, antioxidant activity and carnosic acid content. The overall extraction curve was represented using Sovova’s model; the average deviation between measured and calculated yields was lower than 2%. Mass transfer coefficients in the fluid and solid phases were determined and were compared with previous data reported in the literature for low-scale rosemary supercritical extraction. A two-stage depressurization procedure was accomplished and the effect of both on-line fractionation and extraction time on the antioxidant activity of the samples collected was studied. The antioxidant activity of the different fractions could be straight correlated with the carnosic acid content with a regression coefficient of 0.92This work has been financed by Universidad Autónoma de Madrid and Comunidad Autónoma de Madrid (ALIBIRD-S2009/AGR-1469) and project FUN-C-FOOD, CSD2007-00063 (CONSOLIDER-INGENIO) from Ministerio de Ciencia e Innovación, Spain

Optimization of Countercurrent Supercritical Fluid Extraction of Minor Components from Olive Oil

A process based on the use of a semi-continuous countercurrent supercritical fluid extraction (CC-SFE) has been optimized to concentrate minor components, with functional properties, from olive oil. The optimization of the main variables involved in the supercritical extraction process (extraction pressure, temperature and sample flow rate) was performed using a surface response methodology (RSM). A central composite circumscribed design (CCCD) was employed to study the responses selected to describe the process, such as the extraction yield, the concentration of the different minor compounds (squalene, sterols and tocopherols) in the CO2-rich upper current stream, and the recovery of these compounds from the olive oil. Parameters of the model, for each response variable, were simultaneously estimated by Partial Least Squares (PLS) regression. The statistical analysis of the results allowed obtaining mathematical models able to predict the behavior of the different responses selected as a function of the main variables involved in the process. The optimum conditions obtained, that maximized all the responses as a whole, were: extraction pressure, 234 bar; extraction temperature, 35°C and sample flow rate, 82 mL/h, working with a solvent flow rate equal to 2000 mL/h (S/F equal to 28.4 kg CO2/kg oil). The optimum of the model was experimentally confirmed allowing around 90% recovery of squalene without significant changes on the nutritional and physicochemical properties of the oil

Pressurized Liquid Extraction for the Recovery of Carotenoids and Functional Compounds from Green and Orange Dunaliella salina Biomasses

In recent years, intensive research has been conducted on natural carotenoids extraction using several processes. Conventional extraction methods require high amounts of solvents and a long extraction time. However, pressurized liquid extraction demonstrated to be an interesting method. The extraction efficiencies of pressurized liquid for the recovery of carotenoids, from the green and the orange biomasses of the microalga Dunaliella salina DunaDZ1, are described. Organic solvents were tested including ethanol, n-hexane, ethyl acetate and a mixture of n-hexane:ethanol (3:4). Moreover, three extraction temperatures were used (90, 120 and 150 °C) at constant pressure. Extraction efficiency and extracts characterization were conducted. Results have shown that temperature has a positive effect on extraction yield. HPLC characterization showed that β-carotene is the main carotenoid in the orange biomass, and lutein in the green biomass, with the presence of other minor carotenoids in both biomasses. The highest carotenoid amounts were found in the n-hexane orange biomass extract, with β-carotene isomers as the main carotenoid (138.54 and 357.10 mg/g of dry extract, for cis and trans isomers, respectively). Otherwise, extracts obtained at the lowest tested temperature provided the best carotenoid yields. The best results for the antioxidant activity were obtained at 120 °C for orange biomass ethyl acetate extract

Modelización de motores moleculares: modelo de helicasa

Los motores moleculares son las proteínas encargadas de realizar trabajo mecánico en las escalas típicas de la biología celular; las singularidades de este medio han convertido su modelización en un reto para la física durante los últimos veinte años. En este trabajo se revisan algunos de los modelos utilizados, y se proponen modelos adaptados a la biología de las proteínas helicasa y ARN-polimerasa. Dichos modelos están basados en una aproximación mesoscópica a la dinámica del ADN, y a la interacción proteína-ADN

A kinetic study of the lipase-catalyzed ethanolysis of two short-chain triradylglycerols: Alkylglycerols vs. triacylglycerols

This is the author’s version of a work that was accepted for publication in Journal of Molecular Catalysis B: Enzymatic. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Molecular Catalysis B: Enzymatic, 64, (2010) DOI 10.1016/j.molcatb.2010.02.010Lipase-catalyzed ethanolysis of two short-chain triradylglycerols, namely tributyrin and 2,3-dibutyroil- 1-O-alkylglycerols, have been studied. Much faster rate of reaction for the ethanolysis of tributyrin than that of 2,3-dibutyroil-1-O-alkylglycerols was attained. A kinetic model for the rate of release of ethyl butyrate and for the inactivation of the lipase has been also studied. The parameter corresponding to the release of ethyl butyrate was one order of magnitude higher for ethanolysis of tributyrin than the corresponding of 2,3-dibutyroil-1-O-alkylglycerols. On the contrary, the stability of Novozym 435 during ethanolysis of 2,3-dibutyroil-1-O-alkylglycerols was higher than the corresponding of tributyrin. At the reaction conditions under study, both ethanolysis reactions take place with high selectivity and yield monoesterified alkylglycerols and sn-2 monobutyrin as the main acylglycerols in the reaction mixtures.This work was supported by the projects AGL2006-02031/ALI and AGL2008-05655 by Ministerio de Ciencia (Spain) and also by Comunidad Autonoma de Madrid (ALIBIRD, project number S-505/AGR-0153) and Consolider-Ingenio FUN-C-FOOD (CSD2007- 00063)

Anti-proliferative effect of Rosmarinus officinalis L. extract on human melanoma A375 cells

Rosemary (Rosmarinus officinalis L.) has been used since ancient times in traditional medicine, while nowadays various rosemary formulations are increasingly exploited by alternative medicine to cure or prevent a wide range of health disorders. Rosemary's bioproperties have prompted scientific investigation, which allowed us to ascertain antioxidant, anti-inflammatory, cytostatic, and cytotoxic activities of crude extracts or of pure components. Although there is a growing body of experimental work, information about rosemary's anticancer properties, such as chemoprotective or anti-proliferative effects on cancer cells, is very poor, especially concerning the mechanism of action. Melanoma is a skin tumor whose diffusion is rapidly increasing in the world and whose malignancy is reinforced by its high resistance to cytotoxic agents; hence the availability of new cytotoxic drugs would be very helpful to improve melanoma prognosis. Here we report on the effect of a rosemary hydroalcoholic extract on the viability of the human melanoma A375 cell line. Main components of rosemary extract were identified by liquid chromatography coupled to tandem mass spectrometry (LC/ESI-MS/MS) and the effect of the crude extract or of pure components on the proliferation of cancer cells was tested by MTT and Trypan blue assays. The effect on cell cycle was investigated by using flow cytometry, and the alteration of the cellular redox state was evaluated by intracellular ROS levels and protein carbonylation analysis. Furthermore, in order to get information about the molecular mechanisms of cytotoxicity, a comparative proteomic investigation was performed