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1.
Food Chem ; 414: 135731, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-36821925

RESUMO

The Danish buttered cookie is a famous confectionery product. Its success makes manufacturing of the large volumes required challenging, introducing the need for different strategies to increase production while maintaining a high-quality standard. Two manufacturing lines used are batch-wise and continuous dough mixing. Despite the recipe being the same, the outcome of the two production types differs in texture and external appearance. While this does not infringe on the quality, changes in texture are observable. This manuscript analyses the physicochemical differences of the cookies after baking using Near Infrared hyperspectral imaging and Chemometrics. The study demonstrates that the changes in texture between batch and continuous production are mostly due to the difference in crystalline sucrose emerging in invisible spots on or near the surface of the cookies and a higher tendency of migrated butter-fat spots on the surface of the cookies for the continuous manufacturing procedure.


Assuntos
Manteiga , Imageamento Hiperespectral , Dinamarca
2.
Microorganisms ; 10(11)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36363749

RESUMO

Increasing evidence indicates that the gut microbiome (GM) plays an important role in dyslipidemia. To date, however, no in-depth characterization of the associations between GM with lipoproteins distributions (LPD) among adult individuals with diverse BMI has been conducted. To determine such associations, we studied blood-plasma LPD, fecal short-chain fatty acids (SCFA) and GM of 262 Danes aged 19-89 years. Stratification of LPD segregated subjects into three clusters displaying recommended levels of lipoproteins and explained by age and body-mass-index. Higher levels of HDL2a and HDL2b were associated with a higher abundance of Ruminococcaceae and Christensenellaceae. Increasing levels of total cholesterol and LDL-1 and LDL-2 were positively associated with Lachnospiraceae and Coriobacteriaceae, and negatively with Bacteroidaceae and Bifidobacteriaceae. Metagenome-sequencing showed a higher abundance of biosynthesis of multiple B-vitamins and SCFA metabolism genes among healthier LPD profiles. Metagenomic-assembled genomes (MAGs) affiliated to Eggerthellaceae and Clostridiales were contributors of these genes and their relative abundance correlated positively with larger HDL subfractions. The study demonstrates that differences in composition and metabolic traits of the GM are associated with variations in LPD among the recruited subjects. These findings provide evidence for GM considerations in future research aiming to shed light on mechanisms of the GM-dyslipidemia axis.

3.
J Sci Food Agric ; 102(9): 3808-3816, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34921687

RESUMO

BACKGROUND: As an inherently quantitative and unbiased analytical technique, proton nuclear magnetic resonance (1 H-NMR) provides an excellent method to monitor the quality of food and beverages, and a sensitive and informative tool to study the winemaking process. RESULTS: By using NMR, it is possible to monitor quantitative changes in wine metabolites (amino acids, organic acids and some phenolic compounds) during the winemaking process, including wine ageing. This study shows an increase in the concentration of the phenols at the beginning of alcoholic fermentation, as well as a stabilization and slight increase in gallic acid and a slight decrease in resveratrol during the oak barrel ageing step. CONCLUSION: This study demonstrates the potential of NMR as a process analytical technology (PAT) tool in the wine industry, by monitoring amino acids, organic acids and three polyphenols - gallic acid, catechin and resveratrol - during the winemaking process. This study of the time course evolution of wine has been conducted in a commercial winery rather than an experimental laboratory, demonstrating the capacity of this technique in commercial winemaking production. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Vinho , Aminoácidos , Fermentação , Ácido Gálico , Espectroscopia de Ressonância Magnética/métodos , Fenóis/análise , Resveratrol , Vinho/análise
4.
Am J Clin Nutr ; 113(4): 790-800, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33564844

RESUMO

BACKGROUND: Protein supplementation alone or combined with resistance training has been proposed to be effective in counteracting age-related losses of muscle mass and strength. OBJECTIVES: To investigate the effect of protein supplementation alone or combined with light-intensity or heavy-load resistance exercise on muscle size, strength, and function in older adults. METHODS: In a 1-y randomized controlled trial, 208 healthy older adults (>65 y) were randomly assigned to 1 of 5 interventions: 1) carbohydrate supplementation (CARB); 2) collagen protein supplementation (COLL); 3) whey protein supplementation (WHEY); 4) light-intensity resistance training 3-5 times/wk with whey protein supplementation (LITW); and 5) heavy resistance training 3 times weekly with whey protein supplementation (HRTW). Protein supplements contained 20 g protein + 10 g carbohydrate, whereas CARB contained 30 g of carbohydrates. All intervention groups received the supplement twice daily. The primary outcome was change in the quadriceps cross-sectional area (qCSA). Secondary outcomes included measures of lower extremity strength and power, functional capabilities, and body composition. RESULTS: There were 184 participants who completed the study. COLL and WHEY did not affect any measured parameter compared to CARB. Compared to WHEY, HRTW improved the qCSA size (between-group difference, +1.68 cm2; 95% CI, +0.41 to +2.95 cm2; P = 0.03), as well as dynamic (+18.4 Nm; 95% CI, +10.1 to +26.6 Nm; P < 10-4) and isometric knee extensor strength (+23.9 Nm; 95% CI, +14.2 to +33.6 Nm; P < 10-5). LITW did not improve the qCSA size, but increased dynamic knee extensor strength compared to WHEY (+13.7 Nm; 95% CI, +5.3 and +22.1 Nm; P = 0.01). CONCLUSIONS: Recommending protein supplementation as a stand-alone intervention for healthy older individuals seems ineffective in improving muscle mass and strength. Only HRTW was effective in both preserving muscle mass and increasing strength. Thus, we recommend that future studies investigate strategies to increase long-term compliance to heavy resistance exercise in healthy older adults. This trial was registered at clinicaltrials.gov as NCT02034760.


Assuntos
Proteínas Alimentares/administração & dosagem , Suplementos Nutricionais , Força Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Treinamento Resistido , Proteínas do Soro do Leite/farmacologia , Idoso , Feminino , Humanos , Masculino , Cooperação do Paciente , Desempenho Físico Funcional , Proteínas do Soro do Leite/administração & dosagem
5.
J Environ Qual ; 49(5): 1310-1321, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016439

RESUMO

In recent years, there has been a surge in the number of applications of Fourier-transform mid-infrared (FTIR) spectroscopy for the characterization of environmental samples and prediction of some of their properties whose measurement has traditionally involved time-consuming and costly methods. However, there are several different mid-infrared techniques available, and there is a gap in knowledge regarding the best-suited technique for recording informative spectra of different types of environmental samples. This study compared the three most widespread FTIR techniques using solid and liquid samples. A total of 11 environmental samples belonging to four categories were analyzed with attenuated total reflectance (ATR), photoacoustic (PAS), and diffuse reflectance (DR) FTIR spectroscopy. Overall, PAS-FTIR was the best technique, providing a greater amount of information, especially for opaque samples (i.e., organic waste, biochar, and soil), than ATR-FTIR and DR-FTIR spectroscopy. Attenuated total reflectance FTIR provided the best spectra for soft samples, such as plant materials, probably due to their ability to achieve good optical contact with the ATR crystal. Finally, DR-FTIR performed relatively well for most samples but was found to be more sensitive to moisture in the samples, resulting in noise in specific areas, and was less sensitive in bond vibrations related to Si.


Assuntos
Solo , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Aging Cell ; 19(3): e13105, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31967716

RESUMO

When humans age, changes in body composition arise along with lifestyle-associated disorders influencing fitness and physical decline. Here we provide a comprehensive view of dietary intake, physical activity, gut microbiota (GM), and host metabolome in relation to physical fitness of 207 community-dwelling subjects aged +65 years. Stratification on anthropometric/body composition/physical performance measurements (ABPm) variables identified two phenotypes (high/low-fitness) clearly linked to dietary intake, physical activity, GM, and host metabolome patterns. Strikingly, despite a higher energy intake high-fitness subjects were characterized by leaner bodies and lower fasting proinsulin-C-peptide/blood glucose levels in a mechanism likely driven by higher dietary fiber intake, physical activity and increased abundance of Bifidobacteriales and Clostridiales species in GM and associated metabolites (i.e., enterolactone). These factors explained 50.1% of the individual variation in physical fitness. We propose that targeting dietary strategies for modulation of GM and host metabolome interactions may allow establishing therapeutic approaches to delay and possibly revert comorbidities of aging.


Assuntos
Ingestão de Alimentos/fisiologia , Ingestão de Energia/fisiologia , Microbioma Gastrointestinal/genética , Vida Independente , Metaboloma , Aptidão Física/fisiologia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Bactérias/genética , Composição Corporal , Estudos Transversais , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Exercício Físico/fisiologia , Feminino , Humanos , Estilo de Vida , Masculino , Metabolômica/métodos , Fenótipo
7.
Clin Chem Lab Med ; 58(1): 103-115, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31553695

RESUMO

Background Characterization of lipoprotein particle profiles (LPPs) (including main classes and subclasses) by means of ultracentrifugation (UC) is highly requested given its clinical potential. However, rapid methods are required to replace the very labor-intensive UC method and one solution is to calibrate rapid nuclear magnetic resonance (NMR)-based prediction models, but the reliability of the UC-response method required for the NMR calibration has been largely overlooked. Methods This study provides a comprehensive repeatability and reproducibility study of various UC-based lipid measurements (cholesterol, triglycerides [TGs], free cholesterol, phospholipids, apolipoprotein [apo]A1 and apoB) in different main classes and subclasses of 25 duplicated fresh plasma samples and of 42 quality control (QC) frozen pooled plasma samples of healthy individuals. Results Cholesterol, apoA1 and apoB measurements were very repeatable in all classes (intraclass correlation coefficient [ICC]: 92.93%-99.54%). Free cholesterol and phospholipid concentrations in main classes and subclasses and TG concentrations in high-density lipoproteins (HDL), HDL subclasses and low-density lipoproteins (LDL) subclasses, showed worse repeatability (ICC: 19.21%-99.08%) attributable to low concentrations, variability introduced during UC and assay limitations. On frozen QC samples, the reproducibility of cholesterol, apoA1 and apoB concentrations was found to be better than for the free cholesterol, phospholipids and TGs concentrations. Conclusions This study shows that for LPPs measurements near or below the limit of detection (LOD) in some of the subclasses, as well as the use of frozen samples, results in worsened repeatability and reproducibility. Furthermore, we show that the analytical assay coupled to UC for free cholesterol and phospholipids have different repeatability and reproducibility. All of this needs to be taken into account when calibrating future NMR-based models.


Assuntos
Análise Química do Sangue/métodos , Lipoproteínas/sangue , Lipoproteínas/isolamento & purificação , Ultracentrifugação/métodos , Colorimetria , Feminino , Congelamento , Humanos , Lipoproteínas/química , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
8.
Biotechnol J ; 12(10)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29034577

RESUMO

An industrial scale biomass production using batch or fed-batch fermentations usually optimized by selection of bacterial strains, tuning fermentation media, feeding strategy, and temperature. However, in-depth investigation of the biomass metabolome during the production may reveal new knowledge for better optimization. In this study, for the first time, the authors investigated seven fermentation batches performed on five Streptoccoccus thermophilus strains during the biomass production at Chr. Hansen (Denmark) in a real life large scale fermentation process. The study is designed to investigate effects of batch fermentation, fermentation time, production line, and yeast extract brands on the biomass metabolome using untargeted GC-MS metabolomics. Processing of the raw GC-MS data using PARAFAC2 revealed a total of 90 metabolites out of which 64 are identified. Partitioning of the data variance according to the experimental design was performed using ASCA and revealed that batch and fermentation time effects and their interaction term were the most significant effects. The yeast extract brand had a smaller impact on the biomass metabolome, while the production line showed no effect. This study shows that in-depth metabolic analysis of fermentation broth provides a new tool for advanced optimization of high-volume-low-cost biomass production by lowering the cost, increase the yield, and augment the product quality.


Assuntos
Técnicas de Cultura Celular por Lotes/métodos , Fermentação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Microbiologia Industrial/métodos , Metabolômica , Streptococcus/metabolismo , Análise de Variância , Biomassa , Meios de Cultura/química , Meios de Cultura/farmacologia , Metaboloma , Streptococcus/efeitos dos fármacos , Streptococcus/crescimento & desenvolvimento , Fatores de Tempo , Leveduras/química
9.
Anal Chim Acta ; 986: 101-108, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28870313

RESUMO

A supercontinuum laser was used to perform the first transmission measurements on intact seeds with long wavelength near-infrared spectroscopy. A total of 105 barley seeds from five different barley genotypes (Bomi, lys5.f, lys5.g, lys16 and lys95) were measured from 2275 to 2375 nm. The mixed-linkage (1→3,1→4)-ß-D-glucan (BG) and protein content was measured with wet chemical analysis for each single seed. A partial least squares model correlated the BG % (w/w) with the spectral measurements with a R2CV and R2PRED of 0.83 and 0.90, respectively. The predictive model for BG could be improved by averaging spectra from the same seed and by replacing the individual seed BG content with the average BG of each barley genotype.


Assuntos
Hordeum/química , Sementes/química , Espectroscopia de Luz Próxima ao Infravermelho , beta-Glucanas/análise , Genótipo , Análise dos Mínimos Quadrados
10.
Anal Chem ; 89(15): 8004-8012, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28692288

RESUMO

Lipoprotein profiling of human blood by 1H nuclear magnetic resonance (NMR) spectroscopy is a rapid and promising approach to monitor health and disease states in medicine and nutrition. However, lack of standardization of measurement protocols has prevented the use of NMR-based lipoprotein profiling in metastudies. In this study, a standardized NMR measurement protocol was applied in a ring test performed across three different laboratories in Europe on plasma and serum samples from 28 individuals. Data was evaluated in terms of (i) spectral differences, (ii) differences in LPD predictions obtained using an existing prediction model, and (iii) agreement of predictions with cholesterol concentrations in high- and low-density lipoproteins (HDL and LDL) particles measured by standardized clinical assays. ANOVA-simultaneous component analysis (ASCA) of the ring test spectral ensemble that contains methylene and methyl peaks (1.4-0.6 ppm) showed that 97.99% of the variance in the data is related to subject, 1.62% to sample type (serum or plasma), and 0.39% to laboratory. This interlaboratory variation is in fact smaller than the maximum acceptable intralaboratory variation on quality control samples. It is also shown that the reproducibility between laboratories is good enough for the LPD predictions to be exchangeable when the standardized NMR measurement protocol is followed. With the successful implementation of this protocol, which results in reproducible prediction of lipoprotein distributions across laboratories, a step is taken toward bringing NMR more into scope of prognostic and diagnostic biomarkers, reducing the need for less efficient methods such as ultracentrifugation or high-performance liquid chromatography (HPLC).


Assuntos
Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Espectroscopia de Prótons por Ressonância Magnética , Adulto , Feminino , Humanos , Laboratórios/normas , Análise dos Mínimos Quadrados , Lipoproteínas VLDL/sangue , Gravidez , Análise de Componente Principal , Espectroscopia de Prótons por Ressonância Magnética/normas , Adulto Jovem
11.
Meat Sci ; 111: 18-26, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26331962

RESUMO

This study investigates how Partial Least Squares regression models for predicting individual fatty acids (FAs) and total FA parameters depend on Raman spectral variation associated with the iodine value in pork backfat. The backfat was sampled from pigs, which were fed with different dietary fat sources and levels. Good correlations between the Raman spectra and the total FA composition parameters and most individual FAs were obtained (R(CV)(2)=0.78-0.90). However, the predictions of the individual FAs are indirect and to a high degree depend on co-variance with the total FA parameters. A new procedure was demonstrated for identifying and characterizing such indirect or non-targeted calibrations. This information is very useful when Raman spectroscopy or other vibrational spectroscopic techniques are used to predict non-targeted quality parameters such as individual FAs as they may lead to inaccurate predictions of future sample if the underlying covariance structure is changed e.g. by new dietary regimes or genotypes.


Assuntos
Dieta/veterinária , Gorduras na Dieta/análise , Ácidos Graxos/análise , Inspeção de Alimentos/métodos , Modelos Biológicos , Sus scrofa/metabolismo , Algoritmos , Animais , Calibragem , Castração/veterinária , Cruzamentos Genéticos , Dinamarca , Dieta/efeitos adversos , Dieta com Restrição de Gorduras/efeitos adversos , Dieta com Restrição de Gorduras/veterinária , Gorduras na Dieta/classificação , Ácidos Graxos/química , Feminino , Qualidade dos Alimentos , Análise dos Mínimos Quadrados , Masculino , Metabolômica/métodos , Análise de Componente Principal , Distribuição Aleatória , Análise Espectral Raman , Propriedades de Superfície , Sus scrofa/crescimento & desenvolvimento
12.
Front Microbiol ; 6: 1374, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26696983

RESUMO

Microbial polysaccharides represent an important class of microbial polymers with diverse functions such as biofilm formation, thickening, and gelling properties as well as health-promoting properties. The broad range of exopolysaccharide (EPS) functionalities has sparked a renewed interest in this class of molecules. Chemical, enzymatic as well as genetic modifications by metabolic engineering can be used to create large numbers of analogous EPS variants with respect to EPS functionality. While this top-down approach is effective in finding new candidates for desired functionality, there seems to be a lack of the corresponding bottom-up approach. The molecular mechanisms of the desired functionalities can be established from Nuclear Magnetic Resonance (NMR) and molecular models and it is proposed that these models can be fed back into the biotechnology by using a quantitative structure-property approach. In this way it will be possible to tailor specific functionality within a given design space. This perspective will include two well-known commercial microbial EPS examples namely gellan and diutan and show how even a limited use of multiphase NMR and molecular modeling can increase the insight into their different properties, which are based on only minor structural differences.

13.
Appl Spectrosc ; 69(3): 323-31, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25760291

RESUMO

Many pharmaceuticals include highly potent active pharmaceutical ingredients (API), which only require a small dosage to obtain the desired therapeutic effect. This leads to a challenge for quantification of the API using process analytical technology, since the standard nondestructive measurement technique, near-infrared spectroscopy, is not able to quantify below 1% (weight/weight (w/w)) API content. In formulations with more than one API, this challenge is further increased. The purpose of this study is to scrutinize the potential of fluorescence spectroscopy for the simultaneous quantification of two APIs: flupentixol (FLU) in low dosage (0.208-0.625% w/w free base) and melitracen (MEL) (4.17-12.5% w/w free base) in a tablet formulation. Despite internal quenching between the ingredients and the two APIs, this paper demonstrates that it is possible to establish calibrations using partial least squares (PLS) regression on unfolded fluorescence landscapes with a root mean square error of prediction and relative error of 0.038% (w/w) and 9.1%, for FLU and 0.344% (w/w) and 4.1% for MEL, respectively.


Assuntos
Antracenos/análise , Flupentixol/análise , Espectrometria de Fluorescência/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Comprimidos/química , Tecnologia Farmacêutica/métodos , Algoritmos , Antracenos/química , Flupentixol/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Comprimidos/análise
14.
Biopolymers ; 101(7): 733-43, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24293377

RESUMO

This article describes an update of POLYS, the POLYSaccharide builder, for generating three-dimensional structures of polysaccharides and complex carbohydrates (Engelsen et al., Biopolymers 1996, 39, 417-433). POLYS is written in portable ANSI C and is now released under an open source license. Using this software, complex branched carbohydrate structures and polysaccharides can be constructed from their primary structure and the relevant monosaccharides stored in database containing information on optimized glycosidic linkage geometries. The constructed three-dimensional structures are described as Cartesian coordinate files which can be used as input to other molecular modeling software. The new version of POLYS includes a large database of monosaccharides and a helical generator to build and optimize regular single helix or double helix structures. To demonstrate the efficiency of POLYS to build carbohydrate structures, four examples of increasing complexity are presented in the manuscript, from simple alpha glucans over complex starch fragments and the double helical structure of amylopectin to the mega-oligosaccharide RhamnoGalacturonan II.


Assuntos
Configuração de Carboidratos , Biologia Computacional/métodos , Polissacarídeos/química , Software , Amilopectina/química , Sequência de Carboidratos , Glucanos/química , Internet , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Molecular , Oligossacarídeos/química , Pectinas/química , Reprodutibilidade dos Testes
15.
Food Chem ; 141(3): 2137-47, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23870939

RESUMO

Fiore Sardo (FS) is a traditional Italian raw ewe's milk cheese carrying a Protected Designation of Origin (PDO). This study investigated the kinetics of FS cheese ripening by physicochemical parameters, microbial counting, and NMR metabolomics using aqueous extracts. Four Fiore Sardo cheeses, manufactured from milk with deliberately added autochthonous lactic acid bacteria (LAB) or commercial starters were studied during a period of 90days of ripening. Major differences in the metabolic profiles were observed amongst the samples as a function of the adjunct culture utilised. (1)H NMR metabolomics in combination with multivariate data analysis was able to classify cheese samples on the basis of their maturation age and the type of added cultures. These findings lay the metabolic basis for the authentication of Fiore Sardo cheese produced in compliance with PDO specifications which allow the use of only native LAB cultures.


Assuntos
Queijo/análise , Lactobacillaceae/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Leite/química , Animais , Queijo/microbiologia , Fermentação , Lactobacillaceae/classificação , Metabolômica , Leite/microbiologia , Ovinos
16.
Food Chem ; 136(1): 130-8, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23017403

RESUMO

Health effects of ß-glucan are typically related to dose, size and viscosity without taking the specific molecular structure into account. High ß-glucan mutant barley, mother barley and oat ß-glucans were large-scale extracted by comparable protocols using hot water, enzyme assisted hydrolysis and ethanol precipitation leading to similar molecular masses (200-300kDa). Multivariate data analysis on all compositional, structural and functional features demonstrated that the main variance among the samples was primarily explained by block structural differences as determined by HPSEC-PAD. In particular the barley high ß-glucan mutant proved to exhibit a unique block structure with DP3 and DP4 contributions of: 78.9% and 16.7% as compared to the barley mother (72.1% and 21.4%) and oat (66.1% and 29.1%). This unique block structure was further confirmed by the (1)H NMR determination of the ß-1,4 to ß-1,3 linkage ratio. Low solubility of the barley samples was potentially an effect of substructures consisting of longer repetitive cellotriosyl sequences. FT-Raman and NMR spectroscopy were useful in measuring sample impurities of α-glucans and prediction of ß-linkage characteristics.


Assuntos
Avena/química , Glucanos/química , Hordeum/química , Avena/genética , Avena/metabolismo , Glucanos/isolamento & purificação , Glucanos/metabolismo , Hordeum/genética , Hordeum/metabolismo , Estrutura Molecular , Peso Molecular , Mutação
17.
Nutrients ; 4(2): 112-131, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22413065

RESUMO

The objective of this study was to identify urinary metabolite profiles that discriminate between high and low intake of dietary protein during a dietary intervention. Seventy-seven overweight, non-diabetic subjects followed an 8-week low-calorie diet (LCD) and were then randomly assigned to a high (HP) or low (LP) protein diet for 6 months. Twenty-four hours urine samples were collected at baseline (prior to the 8-week LCD) and after dietary intervention; at months 1, 3 and 6, respectively. Metabolite profiling was performed by (1)H NMR and chemometrics. Using partial least squares regression (PLS), it was possible to develop excellent prediction models for urinary nitrogen (root mean square error of cross validation (RMSECV) = 1.63 mmol/L; r = 0.89) and urinary creatinine (RMSECV = 0.66 mmol/L; r = 0.98). The obtained high correlations firmly establish the validity of the metabolomic approach since urinary nitrogen is a well established biomarker for daily protein consumption. The models showed that trimethylamine-N-oxide (TMAO) is correlated to urinary nitrogen. Furthermore, urinary creatine was found to be increased by the HP diet whereas citric acid was increased by the LP diet. Despite large variations in individual dietary intake, differentiated metabolite profiles were observed at the dietary group-level.


Assuntos
Dieta com Restrição de Proteínas , Proteínas Alimentares/administração & dosagem , Obesidade/dietoterapia , Urina/química , Adulto , Ácido Cítrico/urina , Creatinina/urina , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Metabolômica , Pessoa de Meia-Idade , Nitrogênio/urina
18.
Genes Nutr ; 7(2): 281-93, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21984257

RESUMO

There is a need for a tool to assess dietary intake related to the habitual dietary glycaemic index (GI) and fibre in groups with large numbers of individuals. Novel metabolite-profiling techniques may be a useful approach when applied to human urine. In a long-term, controlled dietary intervention study, metabolomics were applied to assess dietary patterns. A targeted approach was used to evaluate the effects on urinary C-peptide excretion caused by the dietary treatments. Seventy-seven overweight subjects followed an 8-week low-calorie diet (LCD) and were then randomly assigned to a high-GI or low-GI diet for 6 month during which they completed 24-h urine collections at baseline (prior to the 8-week LCD) and after randomisation to the dietary intervention, at month 1, 3 and 6, respectively. Metabolite profiling in 24-h urine was performed by (1)H NMR and chemometrics. Partial least squares (PLS) analysis indicated that urinary formate could discriminate between high-GI and low-GI diets (correlation coefficient r = 0.82), and this finding was confirmed statistically (P = 0.01). PLS analysis also indicated that urinary hippurate could be associated with fibre intake, but this finding was not confirmed statistically. No associations between GI and urinary C-peptide were found. Our results emphasise that application of metabolomics is useful in the assessment of dietary exposure related to dietary GI and fibre seen at group level in a nutritional metabolomic study of human urine. As our design allowed for large variations in individually selected food items, biomarkers identified at group level may be interpreted as more general and robust markers, largely not confounded with markers from single dietary factors.

19.
J Chromatogr A ; 1218(43): 7832-40, 2011 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-21930276

RESUMO

The Interval Correlation Optimised Shifting algorithm (icoshift) has recently been introduced for the alignment of nuclear magnetic resonance spectra. The method is based on an insertion/deletion model to shift intervals of spectra/chromatograms and relies on an efficient Fast Fourier Transform based computation core that allows the alignment of large data sets in a few seconds on a standard personal computer. The potential of this programme for the alignment of chromatographic data is outlined with focus on the model used for the correction function. The efficacy of the algorithm is demonstrated on a chromatographic data set with 45 chromatograms of 64,000 data points. Computation time is significantly reduced compared to the Correlation Optimised Warping (COW) algorithm, which is widely used for the alignment of chromatographic signals. Moreover, icoshift proved to perform better than COW in terms of quality of the alignment (viz. of simplicity and peak factor), but without the need for computationally expensive optimisations of the warping meta-parameters required by COW. Principal component analysis (PCA) is used to show how a significant reduction on data complexity was achieved, improving the ability to highlight chemical differences amongst the samples.


Assuntos
Algoritmos , Cromatografia Líquida de Alta Pressão/métodos , Processamento de Sinais Assistido por Computador , Modelos Estatísticos , Óleos de Plantas/química , Óleos de Plantas/isolamento & purificação , Análise de Componente Principal
20.
Phytochemistry ; 72(11-12): 1466-72, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21543095

RESUMO

Marama bean (Tylosema esculentum) is an important component of the diet around the Kalahari Desert in Southern Africa where this drought resistant plant can grow. The marama bean contains roughly 1/3 proteins, 1/3 lipids and 1/3 carbohydrates, but despite its potential as dietary supplement little is known about the carbohydrate fraction. In this study the carbohydrate fraction of "immature" and "mature" marama seeds are characterised. The study shows that the marama bean contains negligible amounts of starch and soluble sugars, both far less than 1%. The cell wall is characterised by a high arabinose content and a high resistance to extraction as even a 6M NaOH extraction was insufficient to extract considerable amounts of the arabinose. The arabinose fraction was characterised by arabinan-like linkages and recognised by the arabinan antibody LM6 and LM13 indicating that it is pectic arabinan. Two pools of pectin could be detected; a regular CDTA (1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid) or enzymatically extractable pectin fraction and a recalcitrant pectin fraction containing the majority of the arabinans, of which about 40% was unextractable using 6M NaOH. Additionally, a high content of mannose was observed, possibly from mannosylated storage proteins.


Assuntos
Arabinose/química , Fabaceae/química , Sementes/química , Parede Celular/química , Fracionamento Químico , Ácido Edético/análogos & derivados , Ácido Edético/química , Fabaceae/crescimento & desenvolvimento , Glicosilação , Hidrólise , Pectinas/química , Proteínas de Plantas/química , Sementes/crescimento & desenvolvimento , Solubilidade
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