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Guy M.-M.,Institute of Nutraceuticals and Functional Foods INAF | Tremblay M.,Laval University | Voyer N.,Laval University | Gauthier S.F.,Institute of Nutraceuticals and Functional Foods INAF | Pouliot Y.,Institute of Nutraceuticals and Functional Foods INAF
Journal of Agricultural and Food Chemistry | Year: 2011

The objective of the present work was to investigate the physicochemical conditions that trigger the self-assembly of peptide β-lg f1-8 and therefore lead to nanofibers and hydrogel formation. Nanostructures formed by self-assembly of peptide β-lg f1-8 in the pH range of 2.0-11.0 were studied by transmission electron microscopy (TEM). Hydrogel formation was studied as a function of pH and resulted in evidence of a link between hydrogel formation and the charge distribution carried by the peptide structure. Finally, circular dichroism (CD) spectroscopy was used to characterize the effects of peptide concentration (0.4-2.0 mg/mL), ionic strength (0-1 M NaCl), and temperature (20-80 °C) on the secondary structure of peptide β-lg f1-8. Hydrogels were obtained at peptide concentrations above 2.5 mg/mL. Peptide concentration and pH adjustment were shown to trigger self-assembly of β-lg f1-8, but increasing ionic strength had no effect. Heating to 80 °C induced a stronger CD signal intensity due to an increase in solubility of the peptide, whereas only slight changes in CD pattern were found upon cooling to 20 °C. Overall, results emphasize the role of particular molecular interactions in β-sheet self-assembly of peptide β-lg f1-8 and pH-dependent electrostatic interactions occurring between β-lg f1-8 units, which can explain its propensity to self-assembly. © 2010 American Chemical Society.


Gentes M.-C.,Institute of Nutraceuticals and Functional Foods INAF | Gentes M.-C.,Agriculture and Agri Food Canada | St-Gelais D.,Institute of Nutraceuticals and Functional Foods INAF | St-Gelais D.,Agriculture and Agri Food Canada | Turgeon S.L.,Institute of Nutraceuticals and Functional Foods INAF
Dairy Science and Technology | Year: 2013

Although exopolysaccharides (EPS) produced by lactic acid bacteria can be used to modulate the rheological and physical properties of fermented milk, the interactions between EPS and milk proteins in such complex system remain poorly understood. This work aimed to study the interaction between EPS with different structural characteristics and caseins in the absence or presence of whey proteins in a dairy model system simulating yoghurt conditions. The study was expected to highlight the contribution of whey proteins to the casein network and identify possible interactions of EPS with the casein network. Four starters were used: HC15/210R (control), HC15/291 (neutral, stiff, branched EPS), HC15/702074 (neutral, flexible, highly branched EPS), and 2104/210R (anionic, stiff, linear EPS). Fermentation was performed at 42 C until the pH reached 4.6. Microstructure and rheological and physical properties (syneresis, elastic modulus, and apparent viscosity) were measured. The diversity of EPS functionalities depended on the specific structures of the EPS: stronger gels were formed with the anionic EPS from strain 2104 probably because of electrostatic interactions, although limitation of syneresis was more influenced by the neutrality and stiffness of the EPS backbone of strain 291. The sequential addition of casein and whey proteins to the dairy model system revealed their individual contribution to the microstructure of the protein network. This study showed that the rheological and physical properties of fermented milk can be modulated by the casein and whey protein concentrations and the use of different EPS with specific structural characteristics. © 2013 INRA and Springer-Verlag France.


Bazinet L.,Institute of Nutraceuticals and Functional Foods INAF | Schreyer A.,Institute of Nutraceuticals and Functional Foods INAF | Lessard J.,Université de Sherbrooke
Dairy Science and Technology | Year: 2011

Milk degradation during processing and storage is mainly due to oxidation-reduction reactions. Electroreduction was proposed recently to modulate the redox potential of food such as milk. However, only one study was carried-out on milk with a hydrodynamic electroreduction cell, and this study concluded, according to its protocol, that 4 V was the best anode/cathode voltage difference. But, since electroreduction is an electromembrane process, energy consumption is a major concern. Optimization of milk electroreduction can be one of the ways for improving milk resistance to alteration. Our objectives in the present work were to (1) investigate the effect of low anode/cathode voltage differences on milk redox potential modulation during electroreduction, (2) optimize the process, and (3) compare storage of a low-voltage electroreduced milk with a non-electroreduced milk. It appeared from these results that electroreduction at anode/cathode voltage difference of 3 V was sufficient to ensure a significant decrease in redox potential and dissolved oxygen and allow an energy saving of 79% in comparison with a treatment at 4 V. It appeared also that oxygen is an important parameter to consider during storage of electroreduced milk. To our knowledge, this study is the first one to demonstrate that electroreduction process can be a technological and chemical free alternative to improve stability against oxidation with a low-energy consumption. © INRA and Springer Science+Business Media B.V. 2011.


Perusse L.,Institute of Nutraceuticals and Functional Foods INAF | Perusse L.,Laval University | Plourde M.,Institute of Nutraceuticals and Functional Foods INAF | Plourde M.,Laval University | And 13 more authors.
Obesity | Year: 2013

Inflammation is an important factor linking abdominal obesity with insulin resistance and related cardiometabolic risk. A genome-wide association study of adiposity-related traits performed in the Quebec Family Study (QFS) revealed that a single-nucleotide polymorphism (SNP) in the LRRFIP1 gene (rs11680012) was associated with abdominal adiposity (P = 4.6 × 10-6). Objective: The objective of this study was to assess the relationship between polymorphisms in LRRFIP1 gene and adiposity (BMI, fat mass (FM), waist circumference (WC), and computed tomographyderived areas of total, subcutaneous and visceral abdominal adipose tissue) and markers of inflammation (C-reactive protein (CRP) and interleukin-6 (IL-6)). Design and Methods: Using Sequenom, 16 tag SNPs in the LRRFIP1 gene, capturing 78% of the genetic variation, were genotyped in 926 participants of the QFS. Results: Eight SNPs (rs7575941, rs3769053, rs11689421, rs3820808, rs11680012, rs3806505, rs6739130, and rs11686141) showed evidence of association with at least two adiposity phenotypes and plasma levels of one marker of inflammation. The strongest evidence of association was observed with rs11680012, which explained 1.8-3.4% of the variance in areas of abdominal adiposity and 2.0% of the variation in CRP levels. Carriers of the rare allele of rs11680012 had ∼30% more abdominal adiposity (P values between 2.7 × 10-4 and 3.8 × 10 -6) and 75% higher CRP levels (P = 1.6 × 10-4) than the common allele in age and sex adjusted data. Rs11680012 is a G/C SNP converting an arginine into a threonine and this amino acid substitution may potentially alter exonic splicing. Conclusion: This gene may therefore represent a potential interesting target to investigate in further functional studies on adiposity and inflammation.


Couet N.,Laval University | Desroches S.,Laval University | Desroches S.,Institute of Nutraceuticals and Functional Foods INAF | Robitaille H.,University of Québec | And 6 more authors.
Health Expectations | Year: 2015

Background: We have no clear overview of the extent to which health-care providers involve patients in the decision-making process during consultations. The Observing Patient Involvement in Decision Making instrument (OPTION) was designed to assess this. Objective: To systematically review studies that used the OPTION instrument to observe the extent to which health-care providers involve patients in decision making across a range of clinical contexts, including different health professions and lengths of consultation. Search strategy: We conducted online literature searches in multiple databases (2001-12) and gathered further data through networking. Inclusion criteria: (i) OPTION scores as reported outcomes and (ii) health-care providers and patients as study participants. For analysis, we only included studies using the revised scale. Data extraction: Extracted data included: (i) study and participant characteristics and (ii) OPTION outcomes (scores, statistical associations and reported psychometric results). We also assessed the quality of OPTION outcomes reporting. Main results: We found 33 eligible studies, 29 of which used the revised scale. Overall, we found low levels of patient-involving behaviours: in cases where no intervention was used to implement shared decision making (SDM), the mean OPTION score was 23 ± 14 (0-100 scale). When assessed, the variables most consistently associated with higher OPTION scores were interventions to implement SDM (n = 8/9) and duration of consultations (n = 8/15). Conclusions: Whatever the clinical context, few health-care providers consistently attempt to facilitate patient involvement, and even fewer adjust care to patient preferences. However, both SDM interventions and longer consultations could improve this. © 2013 John Wiley & Sons Ltd.


Ndiaye N.,Institute of Nutraceuticals and Functional Foods INAF | Ndiaye N.,Laval University | Pouliot Y.,Institute of Nutraceuticals and Functional Foods INAF | Pouliot Y.,Laval University | And 6 more authors.
Separation and Purification Technology | Year: 2010

Bovine lactoferrin (LF), a 80 kDa iron-binding glycoprotein, has been reported to have important nutraceutical and biological properties such as anti-inflammatory, antimicrobial and immunostimulatory activities. However, the large scale utilisation of LF requires a cost-effective purification process. The aim of this study was to evaluate the feasibility of separating lactoferrin from whey using electrodialysis with an ultrafiltration membrane (EDUF) system and to study the effect of pH on this protein migration rate during EDUF treatments. Initially, to set the optimum conditions for electroseparation of this molecule, its electrophoretic mobility was measured according to the pH (pH 3-12). LF had an optimal electrophoretic mobility at pH 3.0 of 1.5×10 -8m 2 V -1 s -1 in a 2 g/L KCl solution and of 3.0×10 -8m2 V -1 s -1 in distilled water. Thereafter, a 0.1% LF solution at pH 3.0 was treated by EDUF with an ultrafiltration membrane of 500 kDa molecular weight cut-off. A migration rate going up to 46% was obtained after 4 h of treatment. Finally, the EDUF process was applied on lactoferrin-enriched-whey solutions at pH values of 3.0, 4.0, and 5.0. The highest migration rate for lactoferrin was obtained at pH 3.0 with a migration yield of 15%. Thus, it appeared that the EDUF process could allow the separation of large proteins, such as LF, from a solution. Furthermore, the selectivity of EDUF was decreased in whey solution due to concomitant migration of β-lactoglobulin or other whey proteins. However, the fraction obtained at pH 3.0 presented β-lactoglobulin percentages close to the ones obtained for WPI by ion-exchange technology. © 2010 Elsevier B.V. All rights reserved.


PubMed | Institute of Nutraceuticals and Functional Foods INAF
Type: Journal Article | Journal: Journal of nutrigenetics and nutrigenomics | Year: 2012

Obesity prevalence is growing in our population. Twin studies have estimated the heritability of dietary intakes to about 30%. The objective of this study was to verify whether polymorphisms in genes involved in fatty acid metabolism are associated with dietary fat intakes.Seven hundred participants were recruited. A validated food frequency questionnaire was used to assess dietary intakes. PCR-RFLP and TAQMAN methodology were used to genotype PPAR Leu162Val, PPAR Pro12Ala, PPAR -87T>C, PPARGC1 Gly482Ser, FASN Val1483Ile and SREBF1 c.*619C>G. Statistical analyses were executed with SAS statistical package.Carriers of the Ala12 allele of PPAR Pro12Ala polymorphism had higher intakes of total fat (p = 0.04). For FASN Val1483Ile polymorphism, significant gene-sex interaction effects were found for total fat and saturated fat intakes (p = 0.02 and p = 0.002, respectively). No significant difference in fat intakes was observed for PPAR Leu162Val, PPAR -87T>C, PPARGC1 Gly482Ser and SREBF1 c.*619C>G polymorphisms.Polymorphisms in PPAR and FASN seem to be associated with dietary fat intakes. Genetic variants are important to take into account when studying dietary intakes.


PubMed | Institute of Nutraceuticals and Functional Foods INAF
Type: Journal Article | Journal: Obesity (Silver Spring, Md.) | Year: 2013

Inflammation is an important factor linking abdominal obesity with insulin resistance and related cardiometabolic risk. A genome-wide association study of adiposity-related traits performed in the Quebec Family Study (QFS) revealed that a single-nucleotide polymorphism (SNP) in the LRRFIP1 gene (rs11680012) was associated with abdominal adiposity (P = 4.6 10(-6)).The objective of this study was to assess the relationship between polymorphisms in LRRFIP1 gene and adiposity (BMI, fat mass (FM), waist circumference (WC), and computed tomography-derived areas of total, subcutaneous and visceral abdominal adipose tissue) and markers of inflammation (C-reactive protein (CRP) and interleukin-6 (IL-6)).Using Sequenom, 16 tag SNPs in the LRRFIP1 gene, capturing 78% of the genetic variation, were genotyped in 926 participants of the QFS.Eight SNPs (rs7575941, rs3769053, rs11689421, rs3820808, rs11680012, rs3806505, rs6739130, and rs11686141) showed evidence of association with at least two adiposity phenotypes and plasma levels of one marker of inflammation. The strongest evidence of association was observed with rs11680012, which explained 1.8-3.4% of the variance in areas of abdominal adiposity and 2.0% of the variation in CRP levels. Carriers of the rare allele of rs11680012 had 30% more abdominal adiposity (P values between 2.7 10(-4) and 3.8 10(-6)) and 75% higher CRP levels (P = 1.6 10(-4)) than the common allele in age and sex adjusted data. Rs11680012 is a G/C SNP converting an arginine into a threonine and this amino acid substitution may potentially alter exonic splicing.This gene may therefore represent a potential interesting target to investigate in further functional studies on adiposity and inflammation.


PubMed | BioK Plus International Inc. and Institute of Nutraceuticals and Functional Foods INAF
Type: Journal Article | Journal: Probiotics and antimicrobial proteins | Year: 2016

The influence of temperature, initial pH, and carbon and nitrogen sources on bacteriocin secreted by Lactococcus lactis MM19 (MM19) and Pediococcus acidilactici MM33 (MM33) was evaluated. It was found that 30 and 45 C were the growth temperatures for higher nisin and pediocin production by MM19 and MM33, respectively. The initial pH values for higher production of nisin and pediocin were 9 and 6, respectively. Glucose and wheat peptone E430 were found as suitable carbon and nitrogen sources, respectively, for highest nisin production by MM19 at 30 C and initial pH of 9. In these conditions, nisin production could be increased by 6.7 times as compared to the control medium (de Man, Rogosa, and Sharpe--MRS broth). Similarly, fructose and pea peptone were suitable carbon and nitrogen sources, respectively, for highest production of pediocin by MM33 at 45 C and initial pH of 6. In these conditions, pediocin production by MM33 was increased by three times as compared to the control medium (tryptone-glucose-yeast extract-TGE broth).


PubMed | Knowledge and Evaluation Research Unit, The Dartmouth Center for Health Care Delivery Science, University of Québec, Laval University and Institute of Nutraceuticals and Functional Foods INAF
Type: Journal Article | Journal: Health expectations : an international journal of public participation in health care and health policy | Year: 2015

We have no clear overview of the extent to which health-care providers involve patients in the decision-making process during consultations. The Observing Patient Involvement in Decision Making instrument (OPTION) was designed to assess this.To systematically review studies that used the OPTION instrument to observe the extent to which health-care providers involve patients in decision making across a range of clinical contexts, including different health professions and lengths of consultation.We conducted online literature searches in multiple databases (2001-12) and gathered further data through networking.(i) OPTION scores as reported outcomes and (ii) health-care providers and patients as study participants. For analysis, we only included studies using the revised scale.Extracted data included: (i) study and participant characteristics and (ii) OPTION outcomes (scores, statistical associations and reported psychometric results). We also assessed the quality of OPTION outcomes reporting.We found 33 eligible studies, 29 of which used the revised scale. Overall, we found low levels of patient-involving behaviours: in cases where no intervention was used to implement shared decision making (SDM), the mean OPTION score was 23 14 (0-100 scale). When assessed, the variables most consistently associated with higher OPTION scores were interventions to implement SDM (n = 8/9) and duration of consultations (n = 8/15).Whatever the clinical context, few health-care providers consistently attempt to facilitate patient involvement, and even fewer adjust care to patient preferences. However, both SDM interventions and longer consultations could improve this.

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