Mirian Feiten - Academia.edu (original) (raw)
Papers by Mirian Feiten
Anais Da Academia Brasileira De Ciencias, 2022
The main goal of the present work was to evaluate the application of ultrasound as a previous ste... more The main goal of the present work was to evaluate the application of ultrasound as a previous step to promote the substrates pre-emulsion in the hydrolysis reaction of macauba kernel oil (MKO). The ultrasound effect on the substrates pre-emulsion was evaluated on the free fatty acid (FFA) content, as well as the process variables (reaction time, percentage of catalyst Lipozyme® RM IM, and buffer solution). Reactions carried out with the substrates pre-emulsion presented higher FFA production, up to a 40 wt% increase in 1 hour of reaction, yielding 80 wt% of FFAs in 8 hours. The use of catalyst in the reaction medium, from 5 to 15 wt%, favored the FFAs production in 2 hours of reaction. Addition of 25 to 100 wt% of buffer solution led to 86 wt% of FFAs in 4 hours of reaction. Enzyme recycling resulted in a slight decrease in the FFA content, although the catalyst had maintained 85% of its initial activity after 30 h of use. Therefore, the ultrasound pre-emulsion previous step allowed a more effi cient hydrolysis reaction of MKO, leading to an increase of up to 40 wt% on the FFA content, when compared to the hydrolysis without such step.
Interfaces Científicas - Educação
Projetos escolares envolvem de maneira dinâmica professores e alunos. Assim, um projeto de interv... more Projetos escolares envolvem de maneira dinâmica professores e alunos. Assim, um projeto de intervenção pedagógica interdisciplinar foi planejado e desenvolvido como uma parceria entre docentes da disciplina de Química e de disciplinas específicas do Curso Técnico em Alimentos Integrado ao Ensino Médio. A experiência de aula intitulada Identificação e caracterização de grupos funcionais orgânicos em moléculas de uso/interesse na área de alimentos ministrada aos alunos do 3º ano, e as atividades de ensino remotas desenvolvidas são relatadas desde sua concepção, planejamento e implementação. Ao final, o impacto da relação teoria-prática no processo de ensino-aprendizagem, com visualização da Química na área de alimentos e no cotidiano em si, foi avaliado através de questionário específico aplicado aos alunos. Os resultados foram muito satisfatórios e fomentam o aprimoramento deste e o desenvolvimento de novos projetos interdisciplinares entre as equipes.
Livro de Memórias do IV SUSTENTARE e VII WIPIS: Workshop internancional de Sustentabilidade, Indicadores e Gestão de Recursos Hídricos
Revista Brasileira de Educação Ambiental (RevBEA)
O descarte de cascas, talos, folhas e sementes no processamento de frutas, hortaliças e cereais g... more O descarte de cascas, talos, folhas e sementes no processamento de frutas, hortaliças e cereais gera quantidades elevadas de resíduos orgânicos, chamando a atenção para o problema ambiental e socioeconômico. Assim, como forma de aproveitar o resíduo da produção de sucos de laranja e/ou limão tão rico em nutrientes, reduzir a produção de resíduos e ainda produzir uma iguaria deliciosa, um Plano de Aula Prática de produção de casquinhas de laranja cristalizadas foi desenvolvido visando à Educação Ambiental dos estudantes do 9º ano do Ensino Fundamental, passível de ser realizado, inclusive, de forma remota, caseira e intuitiva. Dessa forma, o Plano é compartilhado para que possa ser utilizado na condução de aulas práticas por professores da Educação Básica.
Cadernos de Ciência & Tecnologia
O objetivo deste trabalho foi desenvolver biscoitos tipo cookie com adição de farinha de ora-pro-... more O objetivo deste trabalho foi desenvolver biscoitos tipo cookie com adição de farinha de ora-pro-nobis (Pereskia aculeata Miller) (FOPN), seguindo-se três formulações: cookie controle com 0% de FOPN (F1), com 2% de FOPN (F2), e com 5% de FOPN (F3). A FOPN apresentou 6,04% de umidade, 14,56% de cinzas, 3,30% de lipídeos, 11,9% de proteína bruta, 31,37% de fibra bruta, 2,49% de acidez titulável total (ATT), e pH de 5,09. Para os biscoitos tipo cookie, os parâmetros umidade (F1: 4,97%, F2: 5,04%, F3: 5,06%), proteína (F1: 5,9%, F2: 6,2%, F3: 6,5%), fibra bruta (F1: 1,06%, F2: 5,19%, F3: 6,22%), cinzas (F1: 0,99%, F2: 1,37%, F3: 1,88%) e cor (F1: 50,07, F2: 61,42, F3: 69,01) mostraram aumento significativo com o aumento do teor de FOPN (p < 0,05), enquanto outros parâmetros, tais como lipídeos (F1: 14,02%, F2: 13,31%, F3: 13,30%), pH (F1: 7,10, F2: 6,95, F3: 6,92) e sólidos solúveis totais (F1: 34,4 ºBrix, F2: 33,2 ºBrix, F3: 33,1 ºBrix), mostraram redução significativa com o aumento...
Journal of the Brazilian Chemical Society
Fusel oil (FO) is one of the by-products of the sugar-alcohol industry, which has application as ... more Fusel oil (FO) is one of the by-products of the sugar-alcohol industry, which has application as an additional source of higher alcohols for production of esters with flavoring, fuels and lubricants properties, as well as additives in petroleum-based fuels and in pesticide formulations. Thus, this review is focused on the characteristics of FO and its applications as an acyl acceptor in transesterification and esterification reactions for esters production, its addition to fossil fuels, and the herbicidal and fungicidal potential of the compounds presented in its chemical composition. The operating conditions of the process, results obtained, and patented applications in the food, cosmetic, transportation and agricultural sectors are also reported and discussed. Furthermore, main trends, challenges and recommendations are proposed in order to overcome the disadvantages of applying FO in the reported sectors, as well as alternatives for the development of new lines of research are su...
Ultrasonics Sonochemistry, 2011
This work is focused on the optimization of reaction parameters for the synthesis of ascorbyl pal... more This work is focused on the optimization of reaction parameters for the synthesis of ascorbyl palmitate catalyzed by Candida antarctica lipase in different organic solvents under ultrasound irradiation. The sequential strategy of experimental design proved to be useful in determining the optimal conditions for reaction conversion in tert-butanol system using Novozym 435 as catalyst. The optimum production was achieved at 70°C, ascorbic acid to palmitic acid molar ratio of 1:9, enzyme concentration of 5 wt% at 3 h of reaction, resulting in an ascorbyl palmitate conversion of about 27%. Reaction kinetics for ascorbyl palmitate production in ultrasound device showed that satisfactory reaction conversions ($26%) could be achieved in short reaction times (2 h). The empirical kinetic model proposed is able to satisfactorily represent and predict the experimental data.
Anais da Academia Brasileira de Ciências
The main goal of the present work was to evaluate the application of ultrasound as a previous ste... more The main goal of the present work was to evaluate the application of ultrasound as a previous step to promote the substrates pre-emulsion in the hydrolysis reaction of macauba kernel oil (MKO). The ultrasound effect on the substrates pre-emulsion was evaluated on the free fatty acid (FFA) content, as well as the process variables (reaction time, percentage of catalyst Lipozyme® RM IM, and buffer solution). Reactions carried out with the substrates pre-emulsion presented higher FFA production, up to a 40 wt% increase in 1 hour of reaction, yielding 80 wt% of FFAs in 8 hours. The use of catalyst in the reaction medium, from 5 to 15 wt%, favored the FFAs production in 2 hours of reaction. Addition of 25 to 100 wt% of buffer solution led to 86 wt% of FFAs in 4 hours of reaction. Enzyme recycling resulted in a slight decrease in the FFA content, although the catalyst had maintained 85% of its initial activity after 30 h of use. Therefore, the ultrasound pre-emulsion previous step allowed a more effi cient hydrolysis reaction of MKO, leading to an increase of up to 40 wt% on the FFA content, when compared to the hydrolysis without such step.
Educação Contemporânea – Volume 35
Alimentos: Toxicologia e microbiologia & Química e bioquímica
Anais do XX Congresso Brasileiro de Engenharia Química, 2015
Tecnologia e Microbiologia Sob a Perspectiva da Segurança dos Alimentos - Volume 2
Tecnologia e Microbiologia Sob a Perspectiva da Segurança dos Alimentos
Applied Biochemistry and Biotechnology, 2016
The study of enzyme function often involves a multi-disciplinary approach. Several techniques are... more The study of enzyme function often involves a multi-disciplinary approach. Several techniques are documented in the literature towards determining secondary and tertiary structures of enzymes, and X-ray crystallography is the most explored technique for obtaining three-dimensional structures of proteins. Knowledge of three-dimensional structures is essential to understand reaction mechanisms at the atomic level. Additionally, structures can be used to modulate or improve functional activity of enzymes by the production of small molecules that act as substrates/cofactors or by engineering selected mutants with enhanced biological activity. This paper presentes a short overview on how to streamline sample preparation for crystallographic studies of treated enzymes. We additionally revise recent developments on the effects of pressurized fluid treatment on activity and stability of commercial enzymes. Future directions and perspectives on the the role of crystallography as a tool to access the molecular mechanisms underlying enzymatic activity modulation upon treatment in pressurized fluids are also addressed.
Biocatalysis and Agricultural Biotechnology, 2014
This work reports the hydrolysis of fatty acids from soybean oil using a commercial immobilized l... more This work reports the hydrolysis of fatty acids from soybean oil using a commercial immobilized lipase (Lipozyme TL IM) under the influence of ultrasound irradiation. Batch and fed-batch experiments were performed at 65 1C, 10 wt% of enzyme concentration, oil to water molar ratio of 1:9, output irradiation power of 132 W, and 600 rpm agitation. Results show that ultrasound-assisted lipase-catalyzed hydrolysis of oils system might be a potential alternative route to conventional methods, as almost complete reaction yield was achieved for the fed-batch system, with relatively good results for the batch mode at mild irradiation power supply and temperature in a relatively short reaction time, 120 min. Besides, it is shown that the initial reaction rates are of hydrolysis are increased when ultrasound irradiation was applied into the reaction system.
The Journal of Supercritical Fluids, 2008
The objective of this work was to investigate the application of the solution enhanced dispersion... more The objective of this work was to investigate the application of the solution enhanced dispersion by supercritical fluids (SEDS) technique for the precipitation of pure -carotene and copolymer poly(3hydroxybutirate-co-hydroxyvalerate) (PHBV), as well as some encapsulation tests of the solute in the biopolymer. The following parameters were investigated in the precipitation of pure -carotene: pressure (8.0 and 12.0 MPa), anti-solvent flow rate (20-40 mL/min) and concentration of -carotene in an organic dichloromethane solution (4 and 8 mg/mL). For pure -carotene, the results showed that the mean particle size varied from 3.8 to 246.8 m, depending on the processing conditions. The morphology of -carotene was modified from plate-like to leaf-like particles, as verified by micrographs of scanning electronic microscopy (SEM). For the PHBV precipitation, the SEM micrographs showed that for all experimental conditions the morphology of polymer was different from the unprocessed material. The precipitated polymer presented a quasi-spherical shape with interconnected particles in the sub-micrometric range (particle size in the range of 278-570 nm), while the unprocessed material was composed of films and large blocks. The co-precipitation tests showed that the best ratio of -carotene to PHBV in solution was 1:3 (w/w), which resulted in approximately 80% of encapsulation. Fluid phase behavior of the ternary systems CO 2 + dichloromethane + -carotene and CO 2 + dichloromethane + PHBV was also investigated with the aim of elucidating the region of the phase diagram in which the precipitation occurs. Phase equilibrium data were measured in the temperature range of 303-343 K, with CO 2 compositions ranging from 40 to 90 wt% for -carotene, and from 30 to 90 wt% for PHBV. Vapor-liquid and also solid-vapor-liquid phase transitions were observed in the phase equilibrium study. It was observed that the presence of -carotene or PHBV in the ternary mixture had a little influence on the fluid phase behavior of the systems.
![Research paper thumbnail of Precipitation of [beta]-carotene and PHBV and co-precipitation from SEDS technique using supercritical CO2](https://attachments.academia-assets.com/67898203/thumbnails/1.jpg)
](The Journal of …, 2008
The objective of this work was to investigate the application of the solution enhanced dispersion... more The objective of this work was to investigate the application of the solution enhanced dispersion by supercritical fluids (SEDS) technique for the precipitation of pure -carotene and copolymer poly(3hydroxybutirate-co-hydroxyvalerate) (PHBV), as well as some encapsulation tests of the solute in the biopolymer. The following parameters were investigated in the precipitation of pure -carotene: pressure (8.0 and 12.0 MPa), anti-solvent flow rate (20-40 mL/min) and concentration of -carotene in an organic dichloromethane solution (4 and 8 mg/mL). For pure -carotene, the results showed that the mean particle size varied from 3.8 to 246.8 m, depending on the processing conditions. The morphology of -carotene was modified from plate-like to leaf-like particles, as verified by micrographs of scanning electronic microscopy (SEM). For the PHBV precipitation, the SEM micrographs showed that for all experimental conditions the morphology of polymer was different from the unprocessed material. The precipitated polymer presented a quasi-spherical shape with interconnected particles in the sub-micrometric range (particle size in the range of 278-570 nm), while the unprocessed material was composed of films and large blocks. The co-precipitation tests showed that the best ratio of -carotene to PHBV in solution was 1:3 (w/w), which resulted in approximately 80% of encapsulation. Fluid phase behavior of the ternary systems CO 2 + dichloromethane + -carotene and CO 2 + dichloromethane + PHBV was also investigated with the aim of elucidating the region of the phase diagram in which the precipitation occurs. Phase equilibrium data were measured in the temperature range of 303-343 K, with CO 2 compositions ranging from 40 to 90 wt% for -carotene, and from 30 to 90 wt% for PHBV. Vapor-liquid and also solid-vapor-liquid phase transitions were observed in the phase equilibrium study. It was observed that the presence of -carotene or PHBV in the ternary mixture had a little influence on the fluid phase behavior of the systems.
![Research paper thumbnail of Precipitation of [beta]-carotene and PHBV and co-precipitation from SEDS technique using supercritical CO2](https://attachments.academia-assets.com/67898201/thumbnails/1.jpg)
](The Journal of …, 2008
The objective of this work was to investigate the application of the solution enhanced dispersion... more The objective of this work was to investigate the application of the solution enhanced dispersion by supercritical fluids (SEDS) technique for the precipitation of pure -carotene and copolymer poly(3hydroxybutirate-co-hydroxyvalerate) (PHBV), as well as some encapsulation tests of the solute in the biopolymer. The following parameters were investigated in the precipitation of pure -carotene: pressure (8.0 and 12.0 MPa), anti-solvent flow rate (20-40 mL/min) and concentration of -carotene in an organic dichloromethane solution (4 and 8 mg/mL). For pure -carotene, the results showed that the mean particle size varied from 3.8 to 246.8 m, depending on the processing conditions. The morphology of -carotene was modified from plate-like to leaf-like particles, as verified by micrographs of scanning electronic microscopy (SEM). For the PHBV precipitation, the SEM micrographs showed that for all experimental conditions the morphology of polymer was different from the unprocessed material. The precipitated polymer presented a quasi-spherical shape with interconnected particles in the sub-micrometric range (particle size in the range of 278-570 nm), while the unprocessed material was composed of films and large blocks. The co-precipitation tests showed that the best ratio of -carotene to PHBV in solution was 1:3 (w/w), which resulted in approximately 80% of encapsulation. Fluid phase behavior of the ternary systems CO 2 + dichloromethane + -carotene and CO 2 + dichloromethane + PHBV was also investigated with the aim of elucidating the region of the phase diagram in which the precipitation occurs. Phase equilibrium data were measured in the temperature range of 303-343 K, with CO 2 compositions ranging from 40 to 90 wt% for -carotene, and from 30 to 90 wt% for PHBV. Vapor-liquid and also solid-vapor-liquid phase transitions were observed in the phase equilibrium study. It was observed that the presence of -carotene or PHBV in the ternary mixture had a little influence on the fluid phase behavior of the systems.
Anais Da Academia Brasileira De Ciencias, 2022
The main goal of the present work was to evaluate the application of ultrasound as a previous ste... more The main goal of the present work was to evaluate the application of ultrasound as a previous step to promote the substrates pre-emulsion in the hydrolysis reaction of macauba kernel oil (MKO). The ultrasound effect on the substrates pre-emulsion was evaluated on the free fatty acid (FFA) content, as well as the process variables (reaction time, percentage of catalyst Lipozyme® RM IM, and buffer solution). Reactions carried out with the substrates pre-emulsion presented higher FFA production, up to a 40 wt% increase in 1 hour of reaction, yielding 80 wt% of FFAs in 8 hours. The use of catalyst in the reaction medium, from 5 to 15 wt%, favored the FFAs production in 2 hours of reaction. Addition of 25 to 100 wt% of buffer solution led to 86 wt% of FFAs in 4 hours of reaction. Enzyme recycling resulted in a slight decrease in the FFA content, although the catalyst had maintained 85% of its initial activity after 30 h of use. Therefore, the ultrasound pre-emulsion previous step allowed a more effi cient hydrolysis reaction of MKO, leading to an increase of up to 40 wt% on the FFA content, when compared to the hydrolysis without such step.
Interfaces Científicas - Educação
Projetos escolares envolvem de maneira dinâmica professores e alunos. Assim, um projeto de interv... more Projetos escolares envolvem de maneira dinâmica professores e alunos. Assim, um projeto de intervenção pedagógica interdisciplinar foi planejado e desenvolvido como uma parceria entre docentes da disciplina de Química e de disciplinas específicas do Curso Técnico em Alimentos Integrado ao Ensino Médio. A experiência de aula intitulada Identificação e caracterização de grupos funcionais orgânicos em moléculas de uso/interesse na área de alimentos ministrada aos alunos do 3º ano, e as atividades de ensino remotas desenvolvidas são relatadas desde sua concepção, planejamento e implementação. Ao final, o impacto da relação teoria-prática no processo de ensino-aprendizagem, com visualização da Química na área de alimentos e no cotidiano em si, foi avaliado através de questionário específico aplicado aos alunos. Os resultados foram muito satisfatórios e fomentam o aprimoramento deste e o desenvolvimento de novos projetos interdisciplinares entre as equipes.
Livro de Memórias do IV SUSTENTARE e VII WIPIS: Workshop internancional de Sustentabilidade, Indicadores e Gestão de Recursos Hídricos
Revista Brasileira de Educação Ambiental (RevBEA)
O descarte de cascas, talos, folhas e sementes no processamento de frutas, hortaliças e cereais g... more O descarte de cascas, talos, folhas e sementes no processamento de frutas, hortaliças e cereais gera quantidades elevadas de resíduos orgânicos, chamando a atenção para o problema ambiental e socioeconômico. Assim, como forma de aproveitar o resíduo da produção de sucos de laranja e/ou limão tão rico em nutrientes, reduzir a produção de resíduos e ainda produzir uma iguaria deliciosa, um Plano de Aula Prática de produção de casquinhas de laranja cristalizadas foi desenvolvido visando à Educação Ambiental dos estudantes do 9º ano do Ensino Fundamental, passível de ser realizado, inclusive, de forma remota, caseira e intuitiva. Dessa forma, o Plano é compartilhado para que possa ser utilizado na condução de aulas práticas por professores da Educação Básica.
Cadernos de Ciência & Tecnologia
O objetivo deste trabalho foi desenvolver biscoitos tipo cookie com adição de farinha de ora-pro-... more O objetivo deste trabalho foi desenvolver biscoitos tipo cookie com adição de farinha de ora-pro-nobis (Pereskia aculeata Miller) (FOPN), seguindo-se três formulações: cookie controle com 0% de FOPN (F1), com 2% de FOPN (F2), e com 5% de FOPN (F3). A FOPN apresentou 6,04% de umidade, 14,56% de cinzas, 3,30% de lipídeos, 11,9% de proteína bruta, 31,37% de fibra bruta, 2,49% de acidez titulável total (ATT), e pH de 5,09. Para os biscoitos tipo cookie, os parâmetros umidade (F1: 4,97%, F2: 5,04%, F3: 5,06%), proteína (F1: 5,9%, F2: 6,2%, F3: 6,5%), fibra bruta (F1: 1,06%, F2: 5,19%, F3: 6,22%), cinzas (F1: 0,99%, F2: 1,37%, F3: 1,88%) e cor (F1: 50,07, F2: 61,42, F3: 69,01) mostraram aumento significativo com o aumento do teor de FOPN (p < 0,05), enquanto outros parâmetros, tais como lipídeos (F1: 14,02%, F2: 13,31%, F3: 13,30%), pH (F1: 7,10, F2: 6,95, F3: 6,92) e sólidos solúveis totais (F1: 34,4 ºBrix, F2: 33,2 ºBrix, F3: 33,1 ºBrix), mostraram redução significativa com o aumento...
Journal of the Brazilian Chemical Society
Fusel oil (FO) is one of the by-products of the sugar-alcohol industry, which has application as ... more Fusel oil (FO) is one of the by-products of the sugar-alcohol industry, which has application as an additional source of higher alcohols for production of esters with flavoring, fuels and lubricants properties, as well as additives in petroleum-based fuels and in pesticide formulations. Thus, this review is focused on the characteristics of FO and its applications as an acyl acceptor in transesterification and esterification reactions for esters production, its addition to fossil fuels, and the herbicidal and fungicidal potential of the compounds presented in its chemical composition. The operating conditions of the process, results obtained, and patented applications in the food, cosmetic, transportation and agricultural sectors are also reported and discussed. Furthermore, main trends, challenges and recommendations are proposed in order to overcome the disadvantages of applying FO in the reported sectors, as well as alternatives for the development of new lines of research are su...
Ultrasonics Sonochemistry, 2011
This work is focused on the optimization of reaction parameters for the synthesis of ascorbyl pal... more This work is focused on the optimization of reaction parameters for the synthesis of ascorbyl palmitate catalyzed by Candida antarctica lipase in different organic solvents under ultrasound irradiation. The sequential strategy of experimental design proved to be useful in determining the optimal conditions for reaction conversion in tert-butanol system using Novozym 435 as catalyst. The optimum production was achieved at 70°C, ascorbic acid to palmitic acid molar ratio of 1:9, enzyme concentration of 5 wt% at 3 h of reaction, resulting in an ascorbyl palmitate conversion of about 27%. Reaction kinetics for ascorbyl palmitate production in ultrasound device showed that satisfactory reaction conversions ($26%) could be achieved in short reaction times (2 h). The empirical kinetic model proposed is able to satisfactorily represent and predict the experimental data.
Anais da Academia Brasileira de Ciências
The main goal of the present work was to evaluate the application of ultrasound as a previous ste... more The main goal of the present work was to evaluate the application of ultrasound as a previous step to promote the substrates pre-emulsion in the hydrolysis reaction of macauba kernel oil (MKO). The ultrasound effect on the substrates pre-emulsion was evaluated on the free fatty acid (FFA) content, as well as the process variables (reaction time, percentage of catalyst Lipozyme® RM IM, and buffer solution). Reactions carried out with the substrates pre-emulsion presented higher FFA production, up to a 40 wt% increase in 1 hour of reaction, yielding 80 wt% of FFAs in 8 hours. The use of catalyst in the reaction medium, from 5 to 15 wt%, favored the FFAs production in 2 hours of reaction. Addition of 25 to 100 wt% of buffer solution led to 86 wt% of FFAs in 4 hours of reaction. Enzyme recycling resulted in a slight decrease in the FFA content, although the catalyst had maintained 85% of its initial activity after 30 h of use. Therefore, the ultrasound pre-emulsion previous step allowed a more effi cient hydrolysis reaction of MKO, leading to an increase of up to 40 wt% on the FFA content, when compared to the hydrolysis without such step.
Educação Contemporânea – Volume 35
Alimentos: Toxicologia e microbiologia & Química e bioquímica
Anais do XX Congresso Brasileiro de Engenharia Química, 2015
Tecnologia e Microbiologia Sob a Perspectiva da Segurança dos Alimentos - Volume 2
Tecnologia e Microbiologia Sob a Perspectiva da Segurança dos Alimentos
Applied Biochemistry and Biotechnology, 2016
The study of enzyme function often involves a multi-disciplinary approach. Several techniques are... more The study of enzyme function often involves a multi-disciplinary approach. Several techniques are documented in the literature towards determining secondary and tertiary structures of enzymes, and X-ray crystallography is the most explored technique for obtaining three-dimensional structures of proteins. Knowledge of three-dimensional structures is essential to understand reaction mechanisms at the atomic level. Additionally, structures can be used to modulate or improve functional activity of enzymes by the production of small molecules that act as substrates/cofactors or by engineering selected mutants with enhanced biological activity. This paper presentes a short overview on how to streamline sample preparation for crystallographic studies of treated enzymes. We additionally revise recent developments on the effects of pressurized fluid treatment on activity and stability of commercial enzymes. Future directions and perspectives on the the role of crystallography as a tool to access the molecular mechanisms underlying enzymatic activity modulation upon treatment in pressurized fluids are also addressed.
Biocatalysis and Agricultural Biotechnology, 2014
This work reports the hydrolysis of fatty acids from soybean oil using a commercial immobilized l... more This work reports the hydrolysis of fatty acids from soybean oil using a commercial immobilized lipase (Lipozyme TL IM) under the influence of ultrasound irradiation. Batch and fed-batch experiments were performed at 65 1C, 10 wt% of enzyme concentration, oil to water molar ratio of 1:9, output irradiation power of 132 W, and 600 rpm agitation. Results show that ultrasound-assisted lipase-catalyzed hydrolysis of oils system might be a potential alternative route to conventional methods, as almost complete reaction yield was achieved for the fed-batch system, with relatively good results for the batch mode at mild irradiation power supply and temperature in a relatively short reaction time, 120 min. Besides, it is shown that the initial reaction rates are of hydrolysis are increased when ultrasound irradiation was applied into the reaction system.
The Journal of Supercritical Fluids, 2008
The objective of this work was to investigate the application of the solution enhanced dispersion... more The objective of this work was to investigate the application of the solution enhanced dispersion by supercritical fluids (SEDS) technique for the precipitation of pure -carotene and copolymer poly(3hydroxybutirate-co-hydroxyvalerate) (PHBV), as well as some encapsulation tests of the solute in the biopolymer. The following parameters were investigated in the precipitation of pure -carotene: pressure (8.0 and 12.0 MPa), anti-solvent flow rate (20-40 mL/min) and concentration of -carotene in an organic dichloromethane solution (4 and 8 mg/mL). For pure -carotene, the results showed that the mean particle size varied from 3.8 to 246.8 m, depending on the processing conditions. The morphology of -carotene was modified from plate-like to leaf-like particles, as verified by micrographs of scanning electronic microscopy (SEM). For the PHBV precipitation, the SEM micrographs showed that for all experimental conditions the morphology of polymer was different from the unprocessed material. The precipitated polymer presented a quasi-spherical shape with interconnected particles in the sub-micrometric range (particle size in the range of 278-570 nm), while the unprocessed material was composed of films and large blocks. The co-precipitation tests showed that the best ratio of -carotene to PHBV in solution was 1:3 (w/w), which resulted in approximately 80% of encapsulation. Fluid phase behavior of the ternary systems CO 2 + dichloromethane + -carotene and CO 2 + dichloromethane + PHBV was also investigated with the aim of elucidating the region of the phase diagram in which the precipitation occurs. Phase equilibrium data were measured in the temperature range of 303-343 K, with CO 2 compositions ranging from 40 to 90 wt% for -carotene, and from 30 to 90 wt% for PHBV. Vapor-liquid and also solid-vapor-liquid phase transitions were observed in the phase equilibrium study. It was observed that the presence of -carotene or PHBV in the ternary mixture had a little influence on the fluid phase behavior of the systems.
The Journal of …, 2008
The objective of this work was to investigate the application of the solution enhanced dispersion... more The objective of this work was to investigate the application of the solution enhanced dispersion by supercritical fluids (SEDS) technique for the precipitation of pure -carotene and copolymer poly(3hydroxybutirate-co-hydroxyvalerate) (PHBV), as well as some encapsulation tests of the solute in the biopolymer. The following parameters were investigated in the precipitation of pure -carotene: pressure (8.0 and 12.0 MPa), anti-solvent flow rate (20-40 mL/min) and concentration of -carotene in an organic dichloromethane solution (4 and 8 mg/mL). For pure -carotene, the results showed that the mean particle size varied from 3.8 to 246.8 m, depending on the processing conditions. The morphology of -carotene was modified from plate-like to leaf-like particles, as verified by micrographs of scanning electronic microscopy (SEM). For the PHBV precipitation, the SEM micrographs showed that for all experimental conditions the morphology of polymer was different from the unprocessed material. The precipitated polymer presented a quasi-spherical shape with interconnected particles in the sub-micrometric range (particle size in the range of 278-570 nm), while the unprocessed material was composed of films and large blocks. The co-precipitation tests showed that the best ratio of -carotene to PHBV in solution was 1:3 (w/w), which resulted in approximately 80% of encapsulation. Fluid phase behavior of the ternary systems CO 2 + dichloromethane + -carotene and CO 2 + dichloromethane + PHBV was also investigated with the aim of elucidating the region of the phase diagram in which the precipitation occurs. Phase equilibrium data were measured in the temperature range of 303-343 K, with CO 2 compositions ranging from 40 to 90 wt% for -carotene, and from 30 to 90 wt% for PHBV. Vapor-liquid and also solid-vapor-liquid phase transitions were observed in the phase equilibrium study. It was observed that the presence of -carotene or PHBV in the ternary mixture had a little influence on the fluid phase behavior of the systems.
The Journal of …, 2008
The objective of this work was to investigate the application of the solution enhanced dispersion... more The objective of this work was to investigate the application of the solution enhanced dispersion by supercritical fluids (SEDS) technique for the precipitation of pure -carotene and copolymer poly(3hydroxybutirate-co-hydroxyvalerate) (PHBV), as well as some encapsulation tests of the solute in the biopolymer. The following parameters were investigated in the precipitation of pure -carotene: pressure (8.0 and 12.0 MPa), anti-solvent flow rate (20-40 mL/min) and concentration of -carotene in an organic dichloromethane solution (4 and 8 mg/mL). For pure -carotene, the results showed that the mean particle size varied from 3.8 to 246.8 m, depending on the processing conditions. The morphology of -carotene was modified from plate-like to leaf-like particles, as verified by micrographs of scanning electronic microscopy (SEM). For the PHBV precipitation, the SEM micrographs showed that for all experimental conditions the morphology of polymer was different from the unprocessed material. The precipitated polymer presented a quasi-spherical shape with interconnected particles in the sub-micrometric range (particle size in the range of 278-570 nm), while the unprocessed material was composed of films and large blocks. The co-precipitation tests showed that the best ratio of -carotene to PHBV in solution was 1:3 (w/w), which resulted in approximately 80% of encapsulation. Fluid phase behavior of the ternary systems CO 2 + dichloromethane + -carotene and CO 2 + dichloromethane + PHBV was also investigated with the aim of elucidating the region of the phase diagram in which the precipitation occurs. Phase equilibrium data were measured in the temperature range of 303-343 K, with CO 2 compositions ranging from 40 to 90 wt% for -carotene, and from 30 to 90 wt% for PHBV. Vapor-liquid and also solid-vapor-liquid phase transitions were observed in the phase equilibrium study. It was observed that the presence of -carotene or PHBV in the ternary mixture had a little influence on the fluid phase behavior of the systems.