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Carotenóides e composição centesimal de ervilhas (Pisum sativum L.) cruas e processadas / Carotenoids and centesimal composition of raw and cooked peas (Pisum sativum L.)Carvalho, Otilia Teixeira de 10 September 2007 (has links)
A ervilha é um dos alimentos mais produzidos no mundo e, conseqüentemente, tem uma grande importância para a nutrição humana, sendo comercializada sob várias formas: fresca, seca, congelada e enlatada, necessitando de cozimento antes de ser consumida. Sendo assim, podem ocorrer alterações em sua composição durante esses processamentos. O presente trabalho teve como objetivos avaliar as mudanças ocorridas devido ao processamento na composição centesimal e no perfil de carotenóides em ervilhas frescas (tortas - com vagem comestível - e em grão), secas e enlatadas e relacionar esses dados com sua origem e safra. Foram analisados seis lotes de ervilhas tortas provenientes de duas regiões produtoras (cruas e cozidas por 5 minutos), três lotes de ervilhas frescas (cruas e cozidas por 7 minutos), dois lotes de ervilhas enlatadas (processadas e sua matéria-prima) e três lotes de ervilhas secas (cruas e cozidas por 35 minutos). A umidade em ervilhas tortas diferiu entre safras e regiões produtoras e em ervilhas em grão, aumentou após o cozimento em duas amostras e variou entre safras. O cozimento ocasionou perdas nos teores de Resíduo Mineral Fixo (RMF) em ervilhas em grão e secas. Em ervilhas enlatadas, o processamento causou aumento da umidade e RMF, devido à incorporação de água e sais. Os carotenóides encontrados foram a luteína, o β-caroteno e traços de violaxantina. O perfil de carotenóides em ervilhas tortas, em grão e secas não se alterou após o cozimento, já o enlatamento revelou um aumento aparente no teor de luteína em apenas um dos lotes estudados. Os teores de luteína e β-caroteno variaram entre as diferentes épocas de coleta de ervilhas tortas, em grão e secas, porém não foi observada variação entre as duas regiões produtoras de ervilhas tortas. Os teores de luteína variaram entre as matérias-primas dos diferentes fornecedores de ervilhas enlatadas. Apenas o β-caroteno possui atividade pró-vitamínica A, porém está presente em quantidade insuficiente para fazer das ervilhas fontes desse nutriente. / Pea is one of the world\'s most produced foods and therefore has great importance for human nutrition, being commercialized under different conditions: fresh, dried, frozen and canned, and further cooking is needed before being consumed. As a result, processing can cause some changes in its composition. The aim of the present work was to evaluate the changes in the centesimal composition and carotenoids profile of garden peas, snow peas, dry peas and canned peas due to processing and to compare these data according to geographic origin and crop. Six batches of snow peas from two different regions (raw and cooked for 5 min), three batches of garden peas (raw and cooked for 7 min), two batches of canned peas (processed and raw material) and three batches of dry peas (raw and cooked for 35 min) were analyzed. Water content in snow peas differed between crops and region and, in garden peas, it increased after cooking and varied between crops. Cooking caused losses in the ash content of garden and dry peas. In canned peas, processing increased water and ash contents due to absorption of water and salt. Lutein, β-carotene and traces of violaxanthin were identified in all samples. Carotenoids profile of snow, garden and dry peas did not change after cooking while canning caused an apparent increase in lutein contents only in one batch. Snow, garden and dry peas showed differences in lutein and β-carotene amount due to crops, though different regions revealed not to influence snow peas carotenoids content. The raw material from two suppliers of canned peas differed in their content of lutein. Only β-carotene is a pro-vitamin A carotenoid, however it was found in such small quantities that peas can not be considered source of this nutrient.
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Synthesis, fractionation, characterisation and toxicity of naphthenic acids from complex mixturesJones, David January 2013 (has links)
Amongst the polar organic compounds occurring in unrefined and refined crude oils and the associated polluted production waters, complex mixtures of acids, known historically as naphthenic acids (NAs), have achieved prominence. This is particularly because NAs have been designated a toxicant class of concern in the oil sands process-affected water (OSPW) that has accumulated in vast quantities following exploitation of the oil sands of Northern Alberta, Canada in recent years. However, though there have been calls for NAs to be added to pollutant inventories, at the initiation of the current study, little knowledge existed of the exact composition of refined or unrefined NAs. The overall aim of the current study was therefore to identify individual NAs in refined (commercial) and unrefined (e.g. oil sands process-derived) complex mixtures of acids and then to assess the toxicity of any identified NAs. Individual NAs were tentatively identified by interpretation of the electron ionisation mass spectra of methyl ester derivatives, following comprehensive multidimensional gas chromatography-mass spectrometry (GCxGC-MS). Reference acids were then either purchased, or more commonly, where they were not commercially-available, synthesised, mainly by micro-hydrogenation methods, for co-chromatography and comparison of mass spectra of methyl esters with those of unknowns. The synthetic NAs, purified to >97% were then subjected to toxicological assessments using the Microtox™ assay. In all, 34 compounds were obtained pure enough for testing. Microtox results revealed that the toxicity endpoint (50% Inhibition Concentration, IC50) was between 0.004 and 0.7 mM. Exponential and other correlations were noted between carbon number and toxicity in several of the structural groups of acids assayed, which may be beneficial for predictions of toxicity of non-synthesised acids. Although n-hexanoic acid (IC50 0.7 mM) had the lowest toxicity, adamantane-type acids were the least toxic as a group overall. Conversely, the decahydronaphthalene (decalin)-type acids had the largest range of toxicities (IC50 0.004 to 0.3 mM) and the most toxic acid assayed was 3-decalin-1-yl-propanoic acid. According to USEPA guidelines many individual acids can be said to show low to medium toxicity. Since the acids in commercial and unrefined NAs occur in complex mixtures, an attempt was also made to assess mixture toxicity. Mixtures of individual structural groups of acids (e.g. acyclic isoprenoid acids, n-acids) and a mixture of all 34 acids were assessed. Apart from the adamantane sub-group of acids, all of the mixtures showed toxicities lower than the sum of the parts when calculated using equations for Concentration Addition and Model Deviation Ratios (simply the predicted IC50/Observed IC50). A hypothesis that achievement of a critical micelle concentration is required to produce toxicity was proposed to explain the lower than expected results. Some of the mass spectra of NA present in the commercial and unrefined mixtures were inconsistent with those of any of the alicyclic acids synthesised or purchased. These were hypothesised to be aromatic acids. Fractionation experiments of the NA mixtures using silver ion thin layer chromatography and solid phase extraction (Ag+TLC and Ag+SPE) were carried out in order to provide further evidence for aromatic acids. Ag+TLC allowed separation of a methylated NA mixture from OSPW into three distinct fractions; Ag+SPE resulted in eleven fractions, through the use of a wider range of solvents and differential solvent ratios. Analysis of the fractions by GC-MS revealed that each fraction was largely still made up of unresolved acids (as esters), although one or two fractions revealed some resolved acids. Use of averaged mass spectra and mass chromatography on each fraction revealed further resolved chromatographic peaks and associated interpretable mass spectra. Each of eight of the eleven sub-fractions were examined by GC-MS, in some cases by GCxGC-MS, and all by infrared spectroscopy, ultraviolet visible spectrophotometry and elemental analysis. A number of structures were proposed for the aromatic acids, including those with sulphur-containing moieties. It was noted that far from being minor components, aromatic acids comprised ca.25-40% of the OSPW acid extracts.
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Carotenóides e composição centesimal de ervilhas (Pisum sativum L.) cruas e processadas / Carotenoids and centesimal composition of raw and cooked peas (Pisum sativum L.)Otilia Teixeira de Carvalho 10 September 2007 (has links)
A ervilha é um dos alimentos mais produzidos no mundo e, conseqüentemente, tem uma grande importância para a nutrição humana, sendo comercializada sob várias formas: fresca, seca, congelada e enlatada, necessitando de cozimento antes de ser consumida. Sendo assim, podem ocorrer alterações em sua composição durante esses processamentos. O presente trabalho teve como objetivos avaliar as mudanças ocorridas devido ao processamento na composição centesimal e no perfil de carotenóides em ervilhas frescas (tortas - com vagem comestível - e em grão), secas e enlatadas e relacionar esses dados com sua origem e safra. Foram analisados seis lotes de ervilhas tortas provenientes de duas regiões produtoras (cruas e cozidas por 5 minutos), três lotes de ervilhas frescas (cruas e cozidas por 7 minutos), dois lotes de ervilhas enlatadas (processadas e sua matéria-prima) e três lotes de ervilhas secas (cruas e cozidas por 35 minutos). A umidade em ervilhas tortas diferiu entre safras e regiões produtoras e em ervilhas em grão, aumentou após o cozimento em duas amostras e variou entre safras. O cozimento ocasionou perdas nos teores de Resíduo Mineral Fixo (RMF) em ervilhas em grão e secas. Em ervilhas enlatadas, o processamento causou aumento da umidade e RMF, devido à incorporação de água e sais. Os carotenóides encontrados foram a luteína, o β-caroteno e traços de violaxantina. O perfil de carotenóides em ervilhas tortas, em grão e secas não se alterou após o cozimento, já o enlatamento revelou um aumento aparente no teor de luteína em apenas um dos lotes estudados. Os teores de luteína e β-caroteno variaram entre as diferentes épocas de coleta de ervilhas tortas, em grão e secas, porém não foi observada variação entre as duas regiões produtoras de ervilhas tortas. Os teores de luteína variaram entre as matérias-primas dos diferentes fornecedores de ervilhas enlatadas. Apenas o β-caroteno possui atividade pró-vitamínica A, porém está presente em quantidade insuficiente para fazer das ervilhas fontes desse nutriente. / Pea is one of the world\'s most produced foods and therefore has great importance for human nutrition, being commercialized under different conditions: fresh, dried, frozen and canned, and further cooking is needed before being consumed. As a result, processing can cause some changes in its composition. The aim of the present work was to evaluate the changes in the centesimal composition and carotenoids profile of garden peas, snow peas, dry peas and canned peas due to processing and to compare these data according to geographic origin and crop. Six batches of snow peas from two different regions (raw and cooked for 5 min), three batches of garden peas (raw and cooked for 7 min), two batches of canned peas (processed and raw material) and three batches of dry peas (raw and cooked for 35 min) were analyzed. Water content in snow peas differed between crops and region and, in garden peas, it increased after cooking and varied between crops. Cooking caused losses in the ash content of garden and dry peas. In canned peas, processing increased water and ash contents due to absorption of water and salt. Lutein, β-carotene and traces of violaxanthin were identified in all samples. Carotenoids profile of snow, garden and dry peas did not change after cooking while canning caused an apparent increase in lutein contents only in one batch. Snow, garden and dry peas showed differences in lutein and β-carotene amount due to crops, though different regions revealed not to influence snow peas carotenoids content. The raw material from two suppliers of canned peas differed in their content of lutein. Only β-carotene is a pro-vitamin A carotenoid, however it was found in such small quantities that peas can not be considered source of this nutrient.
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Misturas de ésteres produzidos a partir de fontes alternativas de triacilgliceróis : teor de ésteres e contaminantes / Mixtures of esters produced from alternative sources of triacylglycerols : content of esters and contaminantsMelo, Josué Alves 19 December 2016 (has links)
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / In this study we identified the contaminants present in mixtures of methyl
and ethyl esters of samples obtained from alternative sources of
triacylglycerols, such as: Frying oil (OF), Cottonseed oil (OSA), Scum sludge
(EE), Trap grease (GCG). The esters content (TE) of the samples were
determined by gas chromatography with flame ionization detector (GC-FID)
according to methodology NBR 15764. The samples presented TE below
96.5% (m/m), minimum percentage established by the National Agency of
Petroleum, Natural Gas and Biofuels (ANP) to characterize the mixtures as
Biodiesel. The identification of fatty acids methyl or ethyl esters (FAME or
FAEE) in the mixtures were performed by gas chromatography/mass
spectrometry (GC/MS), observing the presence of linear unsaturated esters with
eighteen carbon atoms. By thermogravimetric profile, it was observed that the
OF and OSA samples presented higher contamination by compounds of high
molecular mass, approximately 12.00% (m/m), corroborating TE results.
Reports in the literature indicate the processes of oxidative degradation or
hydrolysis as being responsible for the origin of contaminants in these types of
matrices, reinforced by the values of peroxide index obtained around 196.00
meq kg-1. By the easy ambiente sonic-spray ionization mass spectrometry
technique (EASI-MS), in positive mode, it was possible to attribute the presence
of dimers, confirmed by m/z 625, 673 and 689 ions, in addition to
diacylglycerols (DAG) and triacylglycerols (TAG). The EE and GCG samples
presented higher acid values around 28.00 mg KOH g-1 with higher
contamination by free fatty acids (FFA). The FFA profile was determined by
EASI-MS, in negative mode, and confirmed by derivatization of the samples
with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and posterior GC/MS
analysis. The identified FFAs comprised a range of six to eighteen carbon
atoms with the majority presence of palmitic, linoleic, oleic and stearic acid. In
the optimization of the open column chromatography method (CC) for the
gravimetric determination of ester and contaminant content in the esters
mixtures, the use of the chromatographic column with a 6 mm internal diameter
and the use of hexane:dichloromethane (7:3) to elute the esters, and the use of
ethyl ether:acetonitrile (8:2) to elute the contaminants were ideal conditions
obtained in the optimization of the CC method. The optimized method of CC was applied in all the samples of this work, and the apolar fraction obtained and
representative of the esters had esters contents above 96.5% (m/m). / Neste trabalho foram identificados os contaminantes presentes em
amostras de misturas de ésteres metílicos e etílicos obtidos a partir de fontes
alternativas de triacilgliceróis, tais como: óleo residual de fritura (OF), óleo da
semente de algodão (OSA), escuma de esgoto (EE), gordura da caixa de
gordura (GCG). O teor de ésteres (TE) das amostras foram determinados por
cromatografia gasosa com detector de ionização por chama (GC-FID) conforme
a metodologia NBR 15764. As amostras apresentaram TE abaixo de 96,5%
(m/m), percentual mínimo estabelecido pela Agência Nacional do Petróleo, Gás
Natural e Biocombustíveis (ANP) para se caracterizar as misturas como
Biodiesel. A identificação dos ésteres metílicos ou etílicos de ácidos graxos
(FAME ou FAEE) nas misturas foram realizadas por cromatografia em fase
gasosa/espectrometria de massas (GC/MS), observando a presença majoritária
de ésteres lineares insaturados com dezoito átomos de carbono. Pelo perfil
termogravimétrico, foi observado que as amostras OF e OSA apresentaram
maior contaminação por compostos de alta massa molecular,
aproximadamente 12,00% (m/m), corroborando o TE. Relatos na literatura
apontam os processos de degradação oxidativa ou de hidrólise como sendo os
responsáveis pela origem de contaminantes nestes tipos de matrizes,
reforçados pelos valores de índice de peróxidos obtidos em torno de 196,00
meq kg-1. Pela técnica de ionização ambiente por sonic-spray (EASI-MS), em
modo positivo, foi possível atribuir a presença majoritária de dímeros,
confirmados pelos íons de m/z 625, 673 e 689, além de diacilgliceróis (DAG) e
triacilgliceróis (TAG). As amostras EE e GCG apresentaram maiores índices
de acidez em torno de 28,00 mg KOH g-1 com maiores contaminações por
ácidos graxos livres (FFA). O perfil dos FFA foi determinado por EASI-MS, em
modo negativo, e confirmado por derivatização das amostras com N,Obis(
trimetilsilil)trifluoracetamida (BSTFA) e análise por GC/MS. Os FFA
identificados abrangeram uma faixa de seis a dezoito átomos de carbono com
a presença majoritária do ácido palmítico, linoleico, oleico e esteárico. Na
otimização do método de cromatografia em coluna aberta (CC) para
determinação do teor de ésteres e de contaminantes em amostras de misturas
de ésteres, o uso da coluna cromatográfica com diâmetro interno de 6 mm, e o
uso de hexano:diclorometrano (7:3) para eluição dos ésteres, e o uso de éter etílico:acetonitrila (8:2) para eluição dos contaminantes foram as condições
ideais obtidas na otimização do método de CC. O método otimizado de CC foi
aplicado em todas as amostras deste trabalho, e a fração apolar obtida e
representativa dos ésteres apresentaram teores de ésteres acima de 96,5%
(m/m).
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