Frontotemporal dementia: Plasma metabolomic signature using gas chromatography-mass spectrometry.

Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by progressive impairment in behavior, executive function, and language. The behavioral variant (bvFTD) is the most clinical common form and requires differential diagnosis with atypical Alzheimer's disease (AD) cases. This study aimed to investigate the plasma metabolite profile of patients with bvFTD compared to AD patients and cognitively healthy individuals using gas chromatography coupled to mass spectrometry (GCMS). This study included nine patients with bvFTD, 17 with AD and 15 cognitively healthy controls (training set), whose data were validated on a testing set (eight bvFTD, 14 AD and ten controls). The metabolites were detected by GCMS. A tendency towards a reduction in the levels of palmitoleic, oleic and lauric acids was found in the bvFTD group compared to the AD group; however, no significance after multiple comparison correction was observed. However, bvFTD group showed reduced levels of creatinine, glycine, tryptophan, uric acid, hypoxanthine, serine, valine, threonine, isoleucine, homoserine, methionine, glutamic acid, capric acid, tartronic acid, fumaric acid, and myo-inositol, metabolites related to glycine/serine/threonine, alanine/aspartate/glutamate pathways and aminoacyl-tRNA biosynthesis, when compared to controls. The data suggest that bvFTD patients may present an impairment of amino acid metabolism and the translation process. This pioneering study on bvFTD and its plasma metabolomic signature can be useful to provide new ideas about pathophysiological mechanisms, as well as guide more robust studies in search of possible biomarkers for the diagnosis of this important dementia.

Discrimination between conventional and omega-3 fatty acids enriched eggs by FT-Raman spectroscopy and chemometric tools.

This work developed an analytical method to differentiate conventional and omega-3 fat acids enriched eggs by Raman spectroscopy and multivariate supervised classification with Partial Least Squares Discriminant Analysis (PLS-DA). Forty samples of enriched eggs and forty samples of different types of common eggs from different batches were used to build the model. Firstly, gas chromatography was employed to analyze fatty acid profiles in egg samples. Raman spectra of the yolk extracts were recorded in the range from 3100 to 990 cm-1. PLS-DA model was able to correctly classify samples with nearly 100% success rate. This model was validated estimating appropriate figures of merit. Predictions uncertainties were also estimated by bootstrap resampling. The most discriminant Raman modes were identified based on VIP (variables importance in projection) scores. This method has potential to assist food industries and regulatory agencies for food quality control, allowing detecting frauds and enabling faster and reliable analyzes.

Capillary zone electrophoresis for fatty acids with chemometrics for the determination of milk adulteration by whey addition.

Adulteration of milk with whey is difficult to detect because these two have similar physical and chemical characteristics. The traditional methodologies to monitor this fraud are based on the analysis of caseinomacropeptide. The present study proposes a new approach to detect and quantify this fraud using the fatty acid profiles of milk and whey. Fatty acids C14:0, C16:0, C18:0, C18:1, C18:2 and C18:3 were selected by gas chromatography associated with discriminant analysis to differentiate milk and whey, as they are present in quite different amounts. These six fatty acids were quantified within a short time by capillary zone electrophoresis in a set of adulterated milk samples. The correlation coefficient between the true values of whey addition and the experimental values obtained by this technique was 0.973. The technique is thus useful for the evaluation of milk adulteration with whey, contributing to the quality control of milk in the dairy industry.

Chemical monitoring of canola, corn, olive, soybean and sunflower oils after thermal treatment at conventional temperatures in domestic stoves / Monitoramento químico dos óleos de canola, milho, oliva, soja e girassol após tratamento térmico em temperaturas alcançadas por fogões domésticos

The frying by immersion is a widely used cooking process and it improves the food texture and flavor. This study analyzed the initial thermal oxidation in five edible vegetable oils used for frying. Oils samples were heated twice for 30 minutes, at 180 C and then at 240 C simulating the domestic stoves temperatures. The oils decomposition temperatures were determined by TG, being all of them > 250 C. The FA profile was analyzed by GC-FID and a slight decrease of UFA was found in corn and soybean oils. In canola, olive and sunflower oils, UFA was stable after heating treatment. Minor FA decomposition was found in canola oil, and followed by corn, olive, sunflower and soybean oils. NIR spectroscopy analyzes resulted in an extensive bands overlapping. The spectra were modeled by PCA and the oils were classified into two groups: fresh oil and heated oil, mainly by differing in 1900 nm region, associated with the carboxyl signal decrease, which might be related to the initial FA degradation in samples. It could partially understand what occurs to the vegetable oil in the beginning of its thermo-decomposition. These information are useful to consumers, food industry and health surveillance agency.

A fritura por imersão é um processo de cocção utilizado pela inclusão de textura e sabor aos alimentos. Foi analisada a oxidação térmica inicial de cinco óleos vegetais comestíveis utilizados para fritura de imersão. Amostras de óleos foram aquecidas duas vezes por 30 minutos, a 180 ºC e depois a 240 ºC, simulando-se as temperaturas de fogões domésticos. As temperaturas de decomposição dos óleos foram determinadas por TG, sendo > 250 ºC. O perfil de FA foi analisado por GC-FID, detectando-se pequeno decréscimo dos UFA nos óleos de milho e soja. Nos óleos de canola, oliva e girassol, os UFA foram estáveis após o tratamento térmico. A menor decomposição dos FA foi detectado no óleo de canola, seguido de milho, oliva, soja e girassol. Análises por espectroscopia NIR resultaram em grande sobreposição das bandas. Os espectros foram modelados por PCA, classificando-se os óleos em dois grupos: óleo fresco e óleo aquecido, principalmente pelas diferenças na região de 1900 nm, relacionadas ao decréscimo do sinal de carboxilas, e associadas à degradação inicial dos FA nas amostras. Ainda que parcialmente, pode-se entender o que ocorre com os óleos vegetais no início de termo-decomposição, abrangências que são úteis para consumidores, indústria alimentícia e órgão de vigilância sanitária.

Chemical monitoring of canola, corn, olive, soybean and sunflower oils after thermal treatment at conventional temperatures in domestic stoves / Monitoramento químico de óleos de canola, milho, azeitona, soja e girassol após tratamento térmico a temperaturas convencionais em fogões domésticos

The frying by immersion is a widely used cooking process and it improves the food texture and flavor. This study analyzed the initial thermal oxidation in five edible vegetable oils used forfrying. Oils samples were heated twice for 30 minutes, at 180 °C and then at 240 °C simulating the domestic stoves temperatures. The oils decomposition temperatures were determined byTG, being all of them > 250 °C. The FA profile was analyzed by GC-FID and a slight decrease of UFA was found in corn and soybean oils. In canola, olive and sunflower oils, UFA was stableafter heating treatment. Minor FA decomposition was found in canola oil, and followed by corn, olive, sunflower and soybean oils. NIR spectroscopy analyzes resulted in an extensive bands overlapping. The spectra were modeled by PCA and the oils were classified into two groups: fresh oil and heated oil, mainly by differing in 1900 nm region, associated with the carboxyl signal decrease, which might be related to the initial FA degradation in samples. It could partiallyunderstand what occurs to the vegetable oil in the beginning of its thermo-decomposition. These information are useful to consumers, food industry and health surveillance agency.

A fritura por imersão é um processo de cozimento amplamente utilizado e melhora a textura e o sabor do alimento. Este estudo analisou a oxidação térmica inicial em cinco óleos vegetais comestíveis usados ​​para fritar. As amostras de óleo foram aquecidas duas vezes durante 30 minutos, a 180 ° C e depois a 240 ° C simulando as temperaturas dos fogões domésticos. As temperaturas de decomposição dos óleos foram determinadas por TG, sendo todas elas> 250 ° C. O perfil de FA foi analisado por GC-FID e uma ligeira diminuição de UFA foi encontrada em óleos de milho e de soja. Nos óleos de canola, azeite e girassol, a UFA foi estável após o tratamento térmico. A decomposição menor de FA foi encontrada em óleo de canola, seguido de óleo de milho, azeite, girassol e soja. As análises de espectroscopia NIR resultaram em uma ampla faixa de sobreposição. Os espectros foram modelados por PCA e os óleos foram classificados em dois grupos: óleo fresco e óleo aquecido, principalmente por diferença na região de 1900 nm, associado à diminuição do sinal carboxílico, o que pode estar relacionado à degradação inicial de FA nas amostras. Poderia entender parcialmente o que ocorre ao óleo vegetal no início de sua termo-decomposição. Essas informações são úteis para consumidores, indústria de alimentos e agência de vigilância da saúde.

20 years of fatty acid analysis by capillary electrophoresis.

A review taking into account the literature reports covering 20 years of fatty acid analysis by capillary electrophoresis is presented. This paper describes the evolution of fatty acid analysis using different CE modes such as capillary zone electrophoresis, non-aqueous capillary electrophoresis, micellar electrokinetic capillary chromatography and microemulsion electrokinetic chromatography employing different detection systems, such as ultraviolet-visible, capacitively coupled contactless conductivity, laser-induced fluorescence and mass spectrometry. In summary, the present review signals that CE seems to be an interesting analytical separation technique that is very useful for screening analysis or quantification of the usual fatty acids present in different matrices, offering short analysis times and a simple sample preparation step as inherent advantages in comparison with the classical methodology, making it a separation technique that is very attractive for quality control in industry and government agencies.

Analysis of omega 3 fatty acid in natural and enriched chicken eggs by capillary zone electrophoresis.

Qualitative differentiation between natural and enriched chicken eggs through omega (ω) 3 fatty acid profiles by capillary zone electrophoresis (CZE) under direct UV detection at 200 nm is proposed. The electrolyte background consisted of 12.0 mmol L(-1) tetraborate buffer (pH 9.2) mixed with 12.0 mmol L(-1) Brij 35, 17% acetonitrile (ACN) and 33% methanol (MeOH). Omega 3 fatty acid profile in chicken egg samples were analyzed by CZE system and confirmed by single-quadrupole mass spectrometry with an electrospray ionization probe set to negative ionization mode after sample preparation by the Folch method. The results showed that ω fatty acid profiles analyzed by the CZE approach can be used to chemical markers to monitor fraud, presenting simplicity, short analysis time (10 min) and low cost as advantages.