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Guenard F.,Institute of Nutrition and Functional Foods INAF | Guenard F.,Laval University | Guenard F.,Chu Of Quebec Research Center | Tchernof A.,Laval University | And 11 more authors.
Physiological Genomics

Obesity is associated with an increased risk of Type 2 diabetes and cardiovascular diseases (CVD). The severely obese population is heterogeneous regarding CVD risk profile. Our objective was to identify metabolic pathways potentially associated with development of metabolic syndrome (MetS) through an analysis of overrepresented pathways from differentially methylated genes between severely obese men with (MetS +) and without (MetS -) the MetS. Genome-wide quantitative DNA methylation analysis in VAT of severely obese men was carried out using the Infinium HumanMethylation450 BeadChip. Differences in methylation levels between MetS+ (n = 7) and MetS- (n = 7) groups were tested. Overrepresented pathways from the list of differentially methylated genes were identified and visualized with the Ingenuity Pathway Analysis system. Differential methylation analysis between MetS+ and MetS- groups identified 8,578 methylation probes (3,258 annotated genes) with significant differences in methylation levels (false discovery rate-corrected DiffScore > {pipe}13{pipe} ~P < 0.05). Pathway analysis from differentially methylated genes identified 41 overrepresented (P < 0.05) pathways. The most overrepresented pathways were related to structural components of the cell membrane, inflammation and immunity and cell cycle regulation. This study provides potential targets associated with adipose tissue dysfunction and development of the MetS. © 2014 the American Physiological Society. Source

Serre E.,Institute of Nutrition and Functional Foods INAF | Serre E.,Laval University | Rozoy E.,Institute of Nutrition and Functional Foods INAF | Rozoy E.,Laval University | And 5 more authors.
Separation and Purification Technology

Cranberry is a typical fruit from North America having a very high acidity that makes raw juice hardly acceptable for consumers. In this study, the reduction of juice acidity was investigated using electrodialysis (ED) with different types of membranes and cell configurations. Electrodialysis is an ecofriendly membrane technology used in a large range of food applications. Three different ED configurations were tested at the laboratory scale: Bipolar and anion-exchange membranes (ED2MB), bipolar and ultrafiltration membranes (ED2MBUF), and cation-exchange and ultrafiltration membranes (EDUF). Each configuration was evaluated in terms of juice physicochemical parameters (titratable acidity, conductivity, total soluble solids, color, anthocyanins, organic acids and mineral contents) and electrodialytic parameters (membrane conductivity and thicknesses, global system resistance). In ED2MB configuration, a 40% deacidification rate was reached after 3 h of treatment (80% after 6 h) whereas 0% and only 8% were obtained after 3 h with ED2MBUF and EDUF configurations, respectively. Furthermore, a selective migration of organic acids was observed with the ED2MB configuration: Citric acid (22 ppm/min), malic acid (11 ppm/min) and quinic acid (6.5 ppm/min). Consequently, ED2MB configuration allows the deacidification of cranberry juice and the production of pure acids (no waste generated) without any chemical consumption due to the bipolar membrane in-situ generation of proton and hydroxyl species from water. © 2016 Elsevier B.V. All rights reserved. Source

Gaudreau H.,Institute of Nutrition and Functional Foods INAF | Gaudreau H.,Laval University | Champagne C.P.,Institute of Nutrition and Functional Foods INAF | Champagne C.P.,Agriculture and Agri Food Canada | And 7 more authors.
Food Research International

Exposure to oxygen can cause a decrease in growth rates or a complete inhibition of growth of oxygen-sensitive probiotic bacteria. A recent study in our laboratory demonstrated that the growth of an oxygen-sensitive strain, Lactobacillus helveticus, was stimulated, under aerobic conditions, when the culture medium was enriched with green tea extracts (GTE). However, information on the mechanism by which GTE influenced the growth, in the presence of oxygen, of that strain is limited. In the present work, the effects of GTE concentrations (to 2000 μg/mL) and exposure to oxygen on maximal populations of L. helveticus R0052 cells and bacterial lipids were evaluated using viable counts, infrared spectroscopy and gas chromatography analyses. Supplementation of the culture medium with 0 to 500 μg/mL GTE did not have an effect on the populations reached under microaerophilic conditions and on bacterial lipid structure and composition. However, at 2000 μg/mL GTE, high population levels were reached under microaerophilic conditions concomitant with an increase in lipid order and with important changes in fatty acid composition of the bacterial lipids. Interactions between GTE components and bacterial lipids were shown by spectroscopic results. Moreover, bacterial cells have adapted to the presence of 2000 μg/mL GTE in the growth medium by changing their lipid composition. To the best of our knowledge, this work is the first to establish a relationship between the effects of GTE at 2000 μg/mL on bacterial cell's lipids and a stimulation of growth under microaerophilic conditions of an oxygen-sensitive strain. © 2016 Elsevier Ltd. Source

Araya-Farias M.,Institute of Nutrition and Functional Foods INAF | Araya-Farias M.,Laval University | Araya-Farias M.,CNRS Galen Institute | Gaudreau A.,Institute of Nutrition and Functional Foods INAF | And 5 more authors.
Journal of Agricultural and Food Chemistry

An effective and rapid HPLC-MS method for the simultaneous separation of the eight most abundant tea catechins, gallic acid, and caffeine was developed. These compounds were rapidly separated within 9 min by a linear gradient elution using a Zorbax SB-C18 packed with sub 2 μm particles. This methodology did not require preparative and semipreparative HPLC steps. In fact, diluted tea samples can be easily analyzed using HPLC-MS as described in this study. The use of mass spectrometry detection for quantification of catechins ensured a higher specificity of the method. The percent relative standard deviation was generally lower than 4 and 7% for most of the compounds tested in tea drinks and tea extracts, respectively. Furthermore, the method provided excellent resolution for folate determination alone or in combination with catechins. To date, no HPLC method able to discriminate catechins and folates in a quick analysis has been reported in the literature. © 2014 American Chemical Society. Source

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