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Elenilson Alves G Filho - One of the best experts on this subject based on the ideXlab platform.
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evaluation of thermal and non thermal processing effect on non prebiotic and prebiotic acerola juices using 1h qnmr and gc ms coupled to Chemometrics
Food Chemistry, 2018Co-Authors: Elenilson Alves G Filho, Edy Sousa De Brito, Fabiano A N Fernandes, Lorena Mara A Silva, Nedio Jair Wurlitzer, Maria Cristiane Rabelo, Thatyane Vidal Fonteles, Sueli RodriguesAbstract:Abstract The effects of thermal (pasteurization and sterilization) and non-thermal (ultrasound and plasma) processing on the composition of prebiotic and non-prebiotic acerola juices were evaluated using NMR and GC–MS coupled to Chemometrics. The increase in the amount of Vitamin C was the main feature observed after thermal processing, followed by malic acid, choline, trigonelline, and acetaldehyde. On the other hand, thermal processing increased the amount of 2-furoic acid, a degradation product from ascorbic acid, as well as influenced the decrease in the amount of esters and alcohols. In general, the non-thermal processing did not present relevant effect on juices composition. The addition of prebiotics (inulin and gluco-oligosaccharides) decreased the effect of processing on juices composition, which suggested a protective effect by microencapsulation. Therefore, chemometric evaluation of the 1H qNMR and GC–MS dataset was suitable to follow changes in acerola juice under different processing.
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chemometric analysis of nmr and gc datasets for chemotype characterization of essential oils from different species of ocimum
Talanta, 2018Co-Authors: Joao Vito B De Freitas, Elenilson Alves G Filho, Edy Sousa De Brito, Lorena Mara A Silva, Guilherme Juliao Zocolo, Nilce V GramosaAbstract:Abstract The genus Ocimum (Labiatae) comprises 30 species found in tropical and subtropical regions of the planet, of which species O. basilicum L. and O. gratissimum are widely used in food and traditional medicine. Phytochemical studies on Ocimum have revealed a number of essential oil chemotypes, for example, eugenol, methyl chavicol, linalool, and methyl cinnamate. Since essential oils are commercially assessed according to their content, the aim of this study was to develop a simple and precise method for their qualitative and quantitative analysis using NMR spectroscopy combined with Chemometrics. Seven essential oils from different species of Ocimum, an unknown sample, and a commercial sample were evaluated and the results compared to those from established and precise GC-MS and GC-FID methods. Chemometric evaluation from both 1H NMR and GC-MS data revealed three chemotypes: eugenol for O. gratissimum, O. micranthum, and O. tenuiflorum; estragole for O. basilicum, O. basilicum var. purpuracens, and O. selloi; and methyl cinnamate for O. americanum. The unknown and commercial species were classified as cinnamate and eugenol chemotypes, respectively. Despite the corroborating results, the chemometric analysis revealed the higher robustness (better adjustment) of the 1H NMR model compared to the GC-MS method in terms of certain statistical parameters. The 1H NMR method allows for the detection and quantification of organic compounds in a complex mixture without the need for certified standard compounds. Although GC-MS and GC-FID were able to detect five compounds not observed by NMR spectroscopy, the four most important metabolites (eugenol, estragole, methyl cinnamate, and eucalyptol) were more readily detected and quantified by 1H NMR.
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1h nmr spectroscopy and Chemometrics evaluation of non thermal processing of orange juice
Food Chemistry, 2016Co-Authors: Elenilson Alves G Filho, Francisca Diva Lima Almeida, Rosane S Cavalcante, Edy Sousa De Brito, P J Cullen, Jesus M Frias, Paula Bourke, Fabiano A N FernandesAbstract:This study evaluated the effect of atmospheric cold plasma and ozone treatments on the key compounds (sugars, amino acids and short chain organic acids) in orange juice by NMR and chemometric analysis. The juice was directly and indirectly exposed to atmospheric cold plasma field at 70kV for different treatment time (15, 30, 45 and 60sec). For ozone processing different loads were evaluated. The Principal Component Analysis shown that the groups of compounds are affected differently depending on the processing. The ozone was the processing that more affected the aromatic compounds and atmospheric cold plasma processing affected more the aliphatic compounds. However, these variations did not result in significant changes in orange juice composition as a whole. Thus, NMR data and Chemometrics were suitable to follow quality changes in orange juice processing by atmospheric cold plasma and ozone.
Sandra Kraljevic Pavelic - One of the best experts on this subject based on the ideXlab platform.
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comparison of triacylglycerol analysis by maldi tof ms fatty acid analysis by gc ms and non selective analysis by nirs in combination with Chemometrics for determination of extra virgin olive oil geographical origin a case study
Lwt - Food Science and Technology, 2018Co-Authors: željka Persuric, Lara Saftic, Tomislav Masek, Sandra Kraljevic PavelicAbstract:Abstract Synergy of analytical methods based on chromatography, mass spectrometry and spectroscopy combined with Chemometrics was tested in the herein presented pilot authentication study of Croatian extra virgin olive oils (EVOOs). Fatty acid (FA) composition was determined by gas chromatography-mass spectrometry (GC-MS), triacylglycerol (TAG) composition by matrix-assisted laser desorption ionization time-of-flight/mass spectrometry (MALDI-TOF/MS), and non-selective analysis was done by near-infrared spectroscopy (NIRS). Chemometric methods were applied on measured data where TAG and NIR spectra showed the highest potential for geographical origin discrimination. TAG profiling data had the best classification power for EVOOs in the PCA, whereas PLS-DA models with high classification accuracy were based on NIRS significant variables or TAG data. Furthermore, NIRS data proved valuable in prediction of quality parameters. Therefore, we presented NIRS as quick, cheap and reliable technique for authenticity study of EVOOs, but for complete characterization of olive oils MALDI-TOF/MS was indispensable.
Robert E. Synovec - One of the best experts on this subject based on the ideXlab platform.
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development of gas chromatographic pattern recognition and classification tools for compliance and forensic analyses of fuels a review
Analytica Chimica Acta, 2020Co-Authors: Paige E Sudol, Karisa M Pierce, Sarah E Prebihalo, Kristen J Skogerboe, Bob W Wright, Robert E. SynovecAbstract:Abstract Gas chromatography (GC) is undoubtedly the analytical technique of choice for compositional analysis of petroleum-based fuels. Over the past twenty years, as comprehensive two-dimensional gas chromatography (GC × GC) has evolved, fuel analysis has often been highlighted in scientific reports, since the complexity of fuel analysis allows for illustration of the impressive peak capacity gains afforded by GC × GC. Indeed, several research groups in recent years have applied GC × GC and chemometric data analysis to demonstrate the potential of these analytical tools to address important compliance (tax evasion, tax credits, physical quality standards) and forensic (arson investigations, oil spills) applications involving fuels. None the less, routine use of GC × GC in forensic laboratories has been limited largely by (1) legal and regulatory guidelines, (2) lack of Chemometrics training, and (3) concerns about the reproducibility of GC × GC. The goal of this review is to highlight recent advances in one-dimensional GC (1D-GC) and GC × GC analyses of fuels for compliance and forensic applications, to assist scientists in overcoming the aforementioned hindrances. An introduction to 1D-GC principles, GC × GC technology (column stationary phases and modulators) and several chemometric methods is provided. More specifically, chemometric methods will be broken down into (1) signal preprocessing, (2) peak decomposition, identification and quantification, and (3) classification and pattern recognition. Examples of compliance and forensic applications will be discussed with particular emphasis on the demonstrated success of the employed chemometric methods. This review will hopefully make 1D-GC and GC × GC coupled with chemometric data analysis tools more accessible to the larger scientific community, and aid in eventual widespread standardization.
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review of chemometric analysis techniques for comprehensive two dimensional separations data
Journal of Chromatography A, 2012Co-Authors: Karisa M Pierce, Benjamin Kehimkar, Luke C Marney, Jamin C Hoggard, Robert E. SynovecAbstract:Abstract Comprehensive two-dimensional (2D) separations, such as comprehensive 2D gas chromatography (GC × GC), liquid chromatography (LC × LC), and related instrumental techniques, provide very large and complex data sets. It is often up to the software to assist the analyst in transforming these complex data sets into useful information, and that is precisely where the field of chemometric data analysis plays a pivotal role. Chemometric tools for comprehensive 2D separations are continually being developed and applied as researchers make significant advances in novel state-of-the-art algorithms and software, and as the commercial sector continues to provide user friendly chemometric software. In this review, we build upon previous reviews of this topic, by focusing primarily on advances that have been reported in the past five years. Most of the reports focus on instrumental platforms using GC × GC with either flame ionization detection (FID) or time-of-flight mass spectrometry (TOFMS) detection, or LC × LC with diode array absorbance detection (DAD). The review covers the following general topics: data preprocessing techniques, target analyte techniques, comprehensive nontarget analysis techniques, and software for Chemometrics in multidimensional separations.
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Comprehensive two-dimensional gas chromatography and Chemometrics for the high-speed quantitative analysis of aromatic isomers in a jet fuel using the standard addition method and an objective retention time alignment algorithm
Analytical Chemistry, 2000Co-Authors: Carlos G. Fraga, Bryan J. Prazen, Robert E. SynovecAbstract:A high-speed quantitative analysis of aromatic isomers in a jet fuel sample is performed using comprehensive two-dimensional gas chromatography (GC × GC) and Chemometrics. A GC × GC separation time of 2.8 min is achieved for three aromatic isomers in jet fuel, which is 5 times faster than a reference method in which a single-column separation resolves two of the three isomers of interest. The high-speed GC × GC separation is more than 10 times faster than a recent GC × GC separation that fully resolves the three components of interest in gasoline. The high-speed GC × GC analysis of jet fuel is accomplished through short GC columns, high gas velocities, and partial chromatographic peak resolution followed by chemometric resolution of overlapped peaks. The standard addition method and an objective retention time alignment algorithm are used to correct for retention time variations prior to the chemometric data analysis. The standard addition method corrects for chemical matrix effects that cause analytes in...
Edy Sousa De Brito - One of the best experts on this subject based on the ideXlab platform.
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evaluation of thermal and non thermal processing effect on non prebiotic and prebiotic acerola juices using 1h qnmr and gc ms coupled to Chemometrics
Food Chemistry, 2018Co-Authors: Elenilson Alves G Filho, Edy Sousa De Brito, Fabiano A N Fernandes, Lorena Mara A Silva, Nedio Jair Wurlitzer, Maria Cristiane Rabelo, Thatyane Vidal Fonteles, Sueli RodriguesAbstract:Abstract The effects of thermal (pasteurization and sterilization) and non-thermal (ultrasound and plasma) processing on the composition of prebiotic and non-prebiotic acerola juices were evaluated using NMR and GC–MS coupled to Chemometrics. The increase in the amount of Vitamin C was the main feature observed after thermal processing, followed by malic acid, choline, trigonelline, and acetaldehyde. On the other hand, thermal processing increased the amount of 2-furoic acid, a degradation product from ascorbic acid, as well as influenced the decrease in the amount of esters and alcohols. In general, the non-thermal processing did not present relevant effect on juices composition. The addition of prebiotics (inulin and gluco-oligosaccharides) decreased the effect of processing on juices composition, which suggested a protective effect by microencapsulation. Therefore, chemometric evaluation of the 1H qNMR and GC–MS dataset was suitable to follow changes in acerola juice under different processing.
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chemometric analysis of nmr and gc datasets for chemotype characterization of essential oils from different species of ocimum
Talanta, 2018Co-Authors: Joao Vito B De Freitas, Elenilson Alves G Filho, Edy Sousa De Brito, Lorena Mara A Silva, Guilherme Juliao Zocolo, Nilce V GramosaAbstract:Abstract The genus Ocimum (Labiatae) comprises 30 species found in tropical and subtropical regions of the planet, of which species O. basilicum L. and O. gratissimum are widely used in food and traditional medicine. Phytochemical studies on Ocimum have revealed a number of essential oil chemotypes, for example, eugenol, methyl chavicol, linalool, and methyl cinnamate. Since essential oils are commercially assessed according to their content, the aim of this study was to develop a simple and precise method for their qualitative and quantitative analysis using NMR spectroscopy combined with Chemometrics. Seven essential oils from different species of Ocimum, an unknown sample, and a commercial sample were evaluated and the results compared to those from established and precise GC-MS and GC-FID methods. Chemometric evaluation from both 1H NMR and GC-MS data revealed three chemotypes: eugenol for O. gratissimum, O. micranthum, and O. tenuiflorum; estragole for O. basilicum, O. basilicum var. purpuracens, and O. selloi; and methyl cinnamate for O. americanum. The unknown and commercial species were classified as cinnamate and eugenol chemotypes, respectively. Despite the corroborating results, the chemometric analysis revealed the higher robustness (better adjustment) of the 1H NMR model compared to the GC-MS method in terms of certain statistical parameters. The 1H NMR method allows for the detection and quantification of organic compounds in a complex mixture without the need for certified standard compounds. Although GC-MS and GC-FID were able to detect five compounds not observed by NMR spectroscopy, the four most important metabolites (eugenol, estragole, methyl cinnamate, and eucalyptol) were more readily detected and quantified by 1H NMR.
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1h nmr spectroscopy and Chemometrics evaluation of non thermal processing of orange juice
Food Chemistry, 2016Co-Authors: Elenilson Alves G Filho, Francisca Diva Lima Almeida, Rosane S Cavalcante, Edy Sousa De Brito, P J Cullen, Jesus M Frias, Paula Bourke, Fabiano A N FernandesAbstract:This study evaluated the effect of atmospheric cold plasma and ozone treatments on the key compounds (sugars, amino acids and short chain organic acids) in orange juice by NMR and chemometric analysis. The juice was directly and indirectly exposed to atmospheric cold plasma field at 70kV for different treatment time (15, 30, 45 and 60sec). For ozone processing different loads were evaluated. The Principal Component Analysis shown that the groups of compounds are affected differently depending on the processing. The ozone was the processing that more affected the aromatic compounds and atmospheric cold plasma processing affected more the aliphatic compounds. However, these variations did not result in significant changes in orange juice composition as a whole. Thus, NMR data and Chemometrics were suitable to follow quality changes in orange juice processing by atmospheric cold plasma and ozone.
Soren Balling Engelsen - One of the best experts on this subject based on the ideXlab platform.
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quantitative analysis of nmr spectra with Chemometrics
Journal of Magnetic Resonance, 2008Co-Authors: Hanne Winning, Flemming H Larsen, Soren Balling EngelsenAbstract:Abstract The number of applications of Chemometrics to series of NMR spectra is rapidly increasing due to an emerging interest for quantitative NMR spectroscopy e.g. in the pharmaceutical and food industries. This paper gives an analysis of advantages and limitations of applying the two most common chemometric procedures, Principal Component Analysis (PCA) and Multivariate Curve Resolution (MCR), to a designed set of 231 simple alcohol mixture (propanol, butanol and pentanol) 1 H 400 MHz spectra. The study clearly demonstrates that the major advantage of Chemometrics is the visualisation of larger data structures which adds a new exploratory dimension to NMR research. While robustness and powerful data visualisation and exploration are the main qualities of the PCA method, the study demonstrates that the bilinear MCR method is an even more powerful method for resolving pure component NMR spectra from mixtures when certain conditions are met.
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quantitative vibrational spectroscopy on pectins prediction of the degree of esterification by Chemometrics
Progress in Biotechnology, 1996Co-Authors: Soren Balling Engelsen, Lars NorgaardAbstract:Abstract The importance of the degree of esterification (%DE) to the gelation properties of pectins makes it desirable to obtain a fast and robust method to determine (predict) the %DE in pectin powders. Vibrational spectroscopy is a good candidate for the development of such fast methods as spectrometers and quantitative software algorithms (chemometric methods) becomes more reliable and sophisticated. Present poster is a preliminary report on the quantitative performance of different instrumentations, spectral regions, sampling techniques and software algorithms developed within the area of Chemometrics.
