L'invention concerne des methodes pour fournir des composes ayant un effet antihypertenseur. ... more L'invention concerne des methodes pour fournir des composes ayant un effet antihypertenseur. L'invention concerne plus particulierement des peptides inhibiteurs de l'ACE (enzyme de conversion de l'angiotensine I) qui peuvent etre liberes enzymatiquement a partir des proteines du lactoserum. On propose une methode pour donner un hydrolysat proteique ayant une activite inhibitrice de l'ACE comprenant le traitement d'un substrat contenant des proteines de lactoserum avec une protease neutre bacterienne thermolabile pour produire un hydrolysat primaire et le traitement dudit hydrolysat primaire avec une thermolysine pour produire un hydrolysat secondaire. On propose egalement des hydrolysats et des peptides isoles pouvant etre obtenus par ladite methode et ses utilisations pour la preparation d'un medicament pour inhiber l'activite de l'ACE chez un mammifere, pour reduire la pression sanguine et/ou pour prevenir l'apparition de l'hypertension.
La presente invention porte sur un procede pour produire une composition alimentaire a base de pr... more La presente invention porte sur un procede pour produire une composition alimentaire a base de produits laitiers comprenant des proteines, lequel procede comprend les etapes consistant a (a) traiter le lait de telle sorte qu'au moins 98 % des agents pathogenes sont retires, (b) traiter le lait avec un microfiltre ayant une taille de pores de 0,01 a 2 micrometres de telle sorte qu'au moins une fraction riche en caseine et une fraction riche en proteines de serum sont obtenues, le lait etant soumis a un traitement de chauffage avant ou apres la microfiltration, et, pendant la production, le lait et des produits obtenus a partir du lait n'etant pas soumis a un traitement thermique a une temperature superieure a 90°C, et la fraction riche en proteines de serum et/ou la fraction riche en caseine etant traitees sous la forme d'un produit alimentaire. L'invention porte egalement sur des produits realises a l'aide du procede.
SummaryThe thermal behaviour of β-lactoglobulin was studied by differential scanning calorimetry ... more SummaryThe thermal behaviour of β-lactoglobulin was studied by differential scanning calorimetry (DSC) in the temperature range 40–160 °C. The DSC curves revealed, in addition to the usually observed denaturation peak near 80 °C, a distinct endothermal peak between 130 and 150 °C. When the pH was increased from 6·5, the area under the peak near 80 °C (denaturation heat) decreased significantly, whereas the peak area near 140 °C increased. The temperature of maximum heat absorption in the peaks near both 80 and 140 °C gradually increased as the pH decreased. Addition of sugars and variation of the heating rate both caused a temperature shift of the endothermal heat effect at 140 °C, similar to that at 80 °C. No peak near 140 °C was observed when β-mercapto-ethanol was added to the β-lactoglobulin solution before scanning. The origin and nature of the high temperature denaturation peak is discussed in terms of conformational changes of the protein.
A deficient brain serotonin function has been demonstrated in psychiatric disorders and increases... more A deficient brain serotonin function has been demonstrated in psychiatric disorders and increases in brain serotonin ameliorate emotional and behavioural abnormalities found in depression. The uptake of the serotonin precursor tryptophan into the brain is dependent on nutrients that influence the cerebral availability of tryptophan via a change in the ratio of plasma tryptophan to the sum of the other large neutral amino acids (Trp/LNAA). In the present study, we investigated the time- and dose dependent effects of α-lactalbumin enriched whey protein with a high tryptophan content in combination with two doses of glucose on plasma Trp/LNAA. Twelve healthy subjects participated in a double-blind cross-over study and ingested 200 ml orange juice added with glucose alone or mixed with either 5,10, and 20 g α-lactalbumin or 20 g α-lactalbumin hydrolysate. One half of the subjects received the orange juice with 25 g glucose, whereas the other half of the subjects received the juice with 50 g glucose. Results revealed a relationship between α-lactalbumin dosage and increases in plasma Trp/LNAA [P< 0.001]. Different doses interacted with time-dependent changes in plasma Trp/LNAA [P < 0.0001] such that the most prolonged increase was found with 20 g α-lactalbumin [P < 0.0001]. Changes in plasma Trp/LNAA were not affected by glucose dose. Since increases in plasma Trp/LNAA are indicative of increased serotonin concentrations in the brain, this study shows that ingestion of 20 g α-lactalbumin may be a suitable dietary method to investigate the effect of alterations in brain serotonin.
Journal of agricultural and food chemistry, Jan 5, 2015
Decoration of prebiotic galacto-oligosaccharides (GOS) with sialic acid yields mixtures of GOS an... more Decoration of prebiotic galacto-oligosaccharides (GOS) with sialic acid yields mixtures of GOS and sialylated GOS (Sia-GOS), novel products that are expected to have both prebiotic and anti-adhesive functionalities. The recombinantly produced trans-sialidase enzyme from Trypanosoma cruzi (TcTS), an enzyme with the ability to transfer (α2-3)-linked sialic acid from sialogalactoglycans to asialogalactoglycans, was employed to catalyze this sialylation. As sialic acid acceptor substrates, Vivinal® GOS and derived fractions of specific degree of polymerization, were taken. As sialic acid donor substrates, bovine κ-casein-derived glycomacropeptide [> 99% N-acetylneuraminic acid (Neu5Ac); < 1% N-glycolylneuraminic acid (Neu5Gc)] and bovine blood plasma glycoprotein mixture (45% Neu5Ac; 55% Neu5Gc) were selected, yielding potential food and feed products, respectively. High-pH anion-exchange chromatography, matrix-assisted laser-desorption ionization time-of-flight mass spectrometry,...
L'invention concerne des methodes pour fournir des composes ayant un effet antihypertenseur. ... more L'invention concerne des methodes pour fournir des composes ayant un effet antihypertenseur. L'invention concerne plus particulierement des peptides inhibiteurs de l'ACE (enzyme de conversion de l'angiotensine I) qui peuvent etre liberes enzymatiquement a partir des proteines du lactoserum. On propose une methode pour donner un hydrolysat proteique ayant une activite inhibitrice de l'ACE comprenant le traitement d'un substrat contenant des proteines de lactoserum avec une protease neutre bacterienne thermolabile pour produire un hydrolysat primaire et le traitement dudit hydrolysat primaire avec une thermolysine pour produire un hydrolysat secondaire. On propose egalement des hydrolysats et des peptides isoles pouvant etre obtenus par ladite methode et ses utilisations pour la preparation d'un medicament pour inhiber l'activite de l'ACE chez un mammifere, pour reduire la pression sanguine et/ou pour prevenir l'apparition de l'hypertension.
La presente invention porte sur un procede pour produire une composition alimentaire a base de pr... more La presente invention porte sur un procede pour produire une composition alimentaire a base de produits laitiers comprenant des proteines, lequel procede comprend les etapes consistant a (a) traiter le lait de telle sorte qu'au moins 98 % des agents pathogenes sont retires, (b) traiter le lait avec un microfiltre ayant une taille de pores de 0,01 a 2 micrometres de telle sorte qu'au moins une fraction riche en caseine et une fraction riche en proteines de serum sont obtenues, le lait etant soumis a un traitement de chauffage avant ou apres la microfiltration, et, pendant la production, le lait et des produits obtenus a partir du lait n'etant pas soumis a un traitement thermique a une temperature superieure a 90°C, et la fraction riche en proteines de serum et/ou la fraction riche en caseine etant traitees sous la forme d'un produit alimentaire. L'invention porte egalement sur des produits realises a l'aide du procede.
SummaryThe thermal behaviour of β-lactoglobulin was studied by differential scanning calorimetry ... more SummaryThe thermal behaviour of β-lactoglobulin was studied by differential scanning calorimetry (DSC) in the temperature range 40–160 °C. The DSC curves revealed, in addition to the usually observed denaturation peak near 80 °C, a distinct endothermal peak between 130 and 150 °C. When the pH was increased from 6·5, the area under the peak near 80 °C (denaturation heat) decreased significantly, whereas the peak area near 140 °C increased. The temperature of maximum heat absorption in the peaks near both 80 and 140 °C gradually increased as the pH decreased. Addition of sugars and variation of the heating rate both caused a temperature shift of the endothermal heat effect at 140 °C, similar to that at 80 °C. No peak near 140 °C was observed when β-mercapto-ethanol was added to the β-lactoglobulin solution before scanning. The origin and nature of the high temperature denaturation peak is discussed in terms of conformational changes of the protein.
A deficient brain serotonin function has been demonstrated in psychiatric disorders and increases... more A deficient brain serotonin function has been demonstrated in psychiatric disorders and increases in brain serotonin ameliorate emotional and behavioural abnormalities found in depression. The uptake of the serotonin precursor tryptophan into the brain is dependent on nutrients that influence the cerebral availability of tryptophan via a change in the ratio of plasma tryptophan to the sum of the other large neutral amino acids (Trp/LNAA). In the present study, we investigated the time- and dose dependent effects of α-lactalbumin enriched whey protein with a high tryptophan content in combination with two doses of glucose on plasma Trp/LNAA. Twelve healthy subjects participated in a double-blind cross-over study and ingested 200 ml orange juice added with glucose alone or mixed with either 5,10, and 20 g α-lactalbumin or 20 g α-lactalbumin hydrolysate. One half of the subjects received the orange juice with 25 g glucose, whereas the other half of the subjects received the juice with 50 g glucose. Results revealed a relationship between α-lactalbumin dosage and increases in plasma Trp/LNAA [P< 0.001]. Different doses interacted with time-dependent changes in plasma Trp/LNAA [P < 0.0001] such that the most prolonged increase was found with 20 g α-lactalbumin [P < 0.0001]. Changes in plasma Trp/LNAA were not affected by glucose dose. Since increases in plasma Trp/LNAA are indicative of increased serotonin concentrations in the brain, this study shows that ingestion of 20 g α-lactalbumin may be a suitable dietary method to investigate the effect of alterations in brain serotonin.
Journal of agricultural and food chemistry, Jan 5, 2015
Decoration of prebiotic galacto-oligosaccharides (GOS) with sialic acid yields mixtures of GOS an... more Decoration of prebiotic galacto-oligosaccharides (GOS) with sialic acid yields mixtures of GOS and sialylated GOS (Sia-GOS), novel products that are expected to have both prebiotic and anti-adhesive functionalities. The recombinantly produced trans-sialidase enzyme from Trypanosoma cruzi (TcTS), an enzyme with the ability to transfer (α2-3)-linked sialic acid from sialogalactoglycans to asialogalactoglycans, was employed to catalyze this sialylation. As sialic acid acceptor substrates, Vivinal® GOS and derived fractions of specific degree of polymerization, were taken. As sialic acid donor substrates, bovine κ-casein-derived glycomacropeptide [> 99% N-acetylneuraminic acid (Neu5Ac); < 1% N-glycolylneuraminic acid (Neu5Gc)] and bovine blood plasma glycoprotein mixture (45% Neu5Ac; 55% Neu5Gc) were selected, yielding potential food and feed products, respectively. High-pH anion-exchange chromatography, matrix-assisted laser-desorption ionization time-of-flight mass spectrometry,...
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