Methyl Esters
Mostrando 1-12 de 291 artigos, teses e dissertações.
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1. Catalysts Derived from Thermal Treatments of Hydrocalumite-Type Compounds: Synthesis and Application in Transesterification Reactions
Catalyst performance is a relevant factor in biodiesel production because it can affect the efficiency of the process. This work provides a study of the performance of heterogeneous catalysts for biodiesel production derived from thermal-treated hydrocalumite-type compounds. This work aimed to synthesize and characterize hydrocalumite-type compounds intercal
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Response Factor in GC-FID Methyl Ester Analysis in Several Biodiesels: A Comparative Study of the EN 14103:2011 and ABNT 15764:2015 Methods versus a Proposed GC-FID Procedure for Individual Ester Determination
A gas chromatography method with a flame ionization detector enabled by relative response factor was developed to determine the individual and the total content of esters in biodiesel. This method accounts for different response factors of the detector for a homologous series of esters that may be present in biodiesel. In this way, the determination of the t
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. The influence of cultivar and enzyme treatment on the aroma complex of apple juice
Abstract This paper aims to determine the influence of a cultivar (Golden delicious and Granny Smith) and enzyme treatments (hot and cold) on the aroma complex of clear apple juice. While the composition of aromatic components of the juice was determined by Gas Chromatography Mass Spectrometry (GC/MS) technique, a panel of 24 semi trained evaluators carried
Food Sci. Technol. Publicado em: 2021-06
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4. HSCCC Separations of Rutin Esters Obtained by Enzymatic Reaction Catalyzed by Lipase
The flavonoid rutin presents several pharmacological effects, despite this, its application in the pharmaceutical industry can be significantly limited by its low bioavailability. The development of lipophilic derivatives by esterification of hydroxyl groups with fatty acid chains may be an effective strategy to change their physicochemical properties. This
J. Braz. Chem. Soc.. Publicado em: 2021-03
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5. FATTY ACIDS ANALYSIS AND CHEMOTAXONOMIC CONSIDERATIONS OF MALVOIDEAE (MALVACEAE) SPECIES
Previous researches showed that fatty acids analysis might be a useful tool to support the taxonomic investigation. In this approach the fatty acids content of ten Malvoideae species was analyzed and its chemotaxonomic significance has been investigated. The aerial parts of the species were collected in the Northeast of Brazil and their fatty acid methyl est
Quím. Nova. Publicado em: 2021-02
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6. Optimization of the Reaction Conditions for the Synthesis of Dihydrobenzofuran Neolignans
We have optimized the experimental conditions for the silver(I)-promoted oxidative coupling of methyl p-coumarate (I) and methyl ferulate (II), which is the most frequently used methodology to synthesize the bioactive dihydrobenzofuran neolignans 1 ((±)-trans-dehydrodicoumarate dimethyl ester) and 2 ((±)-trans-dehydrodiferulate dimethyl ester). Most of the
J. Braz. Chem. Soc.. Publicado em: 2021-01
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7. Reusable Heterogeneous SnO2/ZnO Catalyst for Biodiesel Production from Acidified/Acid Oils
A catalyst comprised of SnO2 impregnated on ZnO nanowires, which presented remarkable ability to catalyze fatty acid esterification/transesterification reactions, is reported. For optimization of reaction conditions, artificially acidified soybean oil with 10 wt.% oleic acid was used as a model feed. The optimized conditions were: 150 °C, 6 h, 5 g of oil, c
J. Braz. Chem. Soc.. Publicado em: 2021-01
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8. VOLATILE COMPOUNDS IN CACHAÇAS OBTAINED FROM THREE SUGARCANE VARIETIES CULTIVATED UNDER THE MANAGEMENTS: ORGANIC, CONVENTIONAL AND WITHOUT FERTILIZATION
The volatile compounds present in cachaça can derive from the raw material used in the production of the beverage, from the fermentative process, from distillation or aging. The aim of the research was to evaluate the volatile compounds, in the cachaças from stills produced with different sugarcane varieties, under the organic and conventional managements.
Quím. Nova. Publicado em: 2020-09
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9. Consumo de Oxigênio e Aptidão Cardiorrespiratória | Diferença entre Idade Cronológica e Biológica
Biodiesel made from oils is rich in polyunsaturated fatty acids methyl esters, and, consequently, presents high tendency to oxidize. Biodiesel made from fats, on the other hand, is mainly comprised by saturated chains. Although it is highly stable, they easily crystalize at low temperatures. Blends from both can exhibit optimized properties. In this work, ox
Arq. Bras. Cardiol.. Publicado em: 2020-09
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10. EVALUATION OF THE RELATIVE PROTECTION FACTOR OF ROSEMARY EXTRACT IN BIODIESEL IN THE PRESENCE OF TRANSITION METAL IONS
Biodiesel contains unsaturated methyl esters making it susceptible to oxidation reaction. Among the factors that cause oxidative instability is the contamination by transition metal ions that in small quantities catalyze the oxidation reaction. The objective of this work was to evaluate the relative protection factor of rosemary extract, in biodiesel, in the
Quím. Nova. Publicado em: 2020-09
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11. OXIDATIVE STABILITY AND COLD FILTER PLUGGING POINT OF BIODIESEL BLENDS DERIVED FROM FATS AND SOY OIL
Biodiesel made from oils is rich in polyunsaturated fatty acids methyl esters, and, consequently, presents high tendency to oxidize. Biodiesel made from fats, on the other hand, is mainly comprised by saturated chains. Although it is highly stable, they easily crystalize at low temperatures. Blends from both can exhibit optimized properties. In this work, ox
Quím. Nova. Publicado em: 2020-09
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12. High Conversion of Palm Olein to Ethyl Esters Using a Strong Anion Exchange Resin: Study of the Operational Parameters
Biodiesel, known as a mixture of fatty acid ethyl/methyl esters, is seen as an alternative, ecofriendly, biodegradable and renewable non-fossil fuel. The use of heterogeneous catalysts for biodiesel synthesis can solve several problems associated with the homogeneous alkaline catalyzed-transesterification. Therefore, this work reports the evaluation of the c
J. Braz. Chem. Soc.. Publicado em: 2020-07