Extração supercrítica do óleo de linhaça: construção do extrator, estudo de parâmetros de processo, avaliação química e antioxidante do produto

The aim of the present study was to extract vegetable oil from brown linseed (Linum usitatissimum L.), determine fatty acid levels, the antioxidant capacity of the extracted oil and perform a rapid economic assessment of the SFE process in the manufacture of oil. The experiments were conducted in a test bench extractor capable of operating with carbon dioxide and co-solvents, obeying 23 factorial planning with central point in triplicate, and having process yield as response variable and pressure, temperature and percentage of cosolvent as independent variables. The yield (mass of extracted oil/mass of raw material used) ranged from 2.2% to 28.8%, with the best results obtained at 250 bar and 50ºC, using 5% (v/v) ethanol co-solvent. The influence of the variables on extraction kinetics and on the composition of the linseed oil obtained was investigated. The extraction kinetic curves obtained were based on different mathematical models available in the literature. The Martínez et al. (2003) model and the Simple Single Plate (SSP) model discussed by Gaspar et al. (2003) represented the experimental data with the lowest mean square errors (MSE). A manufacturing cost of US$17.85/kgoil was estimated for the production of linseed oil using TECANALYSIS software and the Rosa and Meireles method (2005). To establish comparisons with SFE, conventional extraction tests were conducted with a Soxhlet device using petroleum ether. These tests obtained mean yields of 35.2% for an extraction time of 5h. All the oil samples were sterilized and characterized in terms of their composition in fatty acids (FA) using gas chromatography. The main fatty acids detected were: palmitic (C16:0), stearic (C18:0), oleic (C18:1), linoleic (C18:2n-6) and α-linolenic (C18:3n-3). The FA contents obtained with Soxhlet dif ered from those obtained with SFE, with higher percentages of saturated and monounsaturated FA with the Soxhlet technique using petroleum ether. With respect to α-linolenic content (main component of linseed oil) in the samples, SFE performed better than Soxhlet extraction, obtaining percentages between 51.18% and 52.71%, whereas with Soxhlet extraction it was 47.84%. The antioxidant activity of the oil was assessed in the β-carotene/linoleic acid system. The percentages of inhibition of the oxidative process reached 22.11% for the SFE oil, but only 6.09% for commercial oil (cold pressing), suggesting that the SFE technique better preserves the phenolic compounds present in the seed, which are likely responsible for the antioxidant nature of the oil. In vitro tests with the sample displaying the best antioxidant response were conducted in rat liver homogenate to investigate the inhibition of spontaneous lipid peroxidation or autooxidation of biological tissue. Linseed oil proved to be more efficient than fish oil (used as standard) in decreasing lipid peroxidation in the liver tissue of Wistar rats, yielding similar results to those obtained with the use of BHT (synthetic antioxidant). Inhibitory capacity may be explained by the presence of phenolic compounds with antioxidant activity in the linseed oil. The results obtained indicate the need for more detailed studies, given the importance of linseed oil as one of the greatest sources of ω3 among vegetable oils

Incisive Canal Deflation for Correct Implant Placement: Case Report

Aim: This article is a case report of a patient in whom the prosthetic planning indicated the necessity of an incisive canal deflation for the correct installation of all implant that is to be osseointegrated.Case Report. In the reopening phase after the bone graft installation, the incisive canal deflation (biopsy of its content) was done and titanium implants were installed with one of them invading the anatomical space occupied previously by the incisive canal. The biopsy analysis showed fragments of the incisive artery and nerve., which are responsible for the anterior upper-tooth pulp, the periodontium vascularization. and the innervation. Front the anastomosis present along with other structures allied with the absence of teeth in the region, there was no detriment to the patient caused by the deflation.Conclusion: Incisive canal deflation is a viable technique in implantology. It can permit ideal prosthetic planning with no detriment to the patient. (Implant Dent 2009;18:473-479)

Conceitos atuais sobre o crescimento e desenvolvimento transversal dos maxilares e oportunidade de expansão mandibular

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Foraging activity of Protopolybia exigua (Hymenoptera, Vespidae) in different phases of the colony cycle, at an area in the region of the Médio São Francisco River, Bahia, Brazil

In this work, the foraging activity of Protopolybia exigua (de Saussure) was studied, aiming to verify the amplitude of the foraging time, the relation between the physical factors of weather (temperature, relative air humidity, luminosity and wind speed) and the daily activity of searching for resources, as well as to analyze the influence of the colony development phases and the number of individuals (adults and immatures) engaged in such activity. The study was carried out in two areas of the city of Bom Jesus da Lapa, Bahia, Brazil, during the period from January to June 2006, when the observation of 12 colonies of P. exigua was performed. The results revealed this species presented an amplitude of activity of almost 13 hours. There was an average of 44.4 nest exits and 37.6 returns a day by the nest workers and the Returns with Resources Index for this species was 93.5%. The foraging activity increased as of 10:01, and became more intense, with the peak from 1:01 p.m. to 4:00 p.m., when the highest temperatures (°C) and the lowest values of relative air humidity (%) were observed. The colonies that had a larger number of larvae presented a higher average number of trips to the field per hour (10.94) and the number of females in the colony tends to induce foraging activity. There were no differences between the numbers of nest exits by the workers regarding the three phases of colony development.

Olhares que pensam e sentem: arte e mediação cultural na aula de geometria

Pós-graduação em Artes - IA

Planejamento ambiental da bacia hidrográfica do Córrego do Cedro - Presidente Prudente/SP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bancada multifuncional para simulação de mecanismos de falhas em máquinas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A regional reserve fund for Latin America

Includes bibliography.

Análise crítica dos planos e ações de controle e combate a erosões: Estudo de caso da bacia hidrográfica do TURVO/GRANDE

Pós-graduação em Engenharia Civil - FEIS

Horários de atividade forrageadora e itens coletados por Protopolybia exigua (de Saussure) (Hymenoptera, Vespidae) na região do médio São Francisco, Bahia

Pós-graduação em Ciências Biológicas (Zoologia) - IBRC

Estudos bioquímicos de tegumento de soja brasileira: isolamento, purificação e caracterização de peroxidase com guaiacol como substrato

Pós-graduação em Biotecnologia - IQ

Rodas compactadoras e aterradoras na qualidade de acabamento de semeadura direta

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Proposta metodológica para ocupação urbana em áreas de mananciais hídricos: o caso de uma área da bacia hidrográfica do Guarapiranga

Pós-graduação em Geociências e Meio Ambiente - IGCE