Thermal Denaturation of Pea Globulins (Pisum sativum L.)—Molecular Interactions Leading to Heat-Induced Protein Aggregation
The heat-induced denaturation and aggregation of mixed pea globulins (8%, w/w) were investigated using differential scanning calorimetry (DSC), SDS-PAGE, and size-exclusion chromatography (SEC-HPLC). DSC data showed that the pea proteins denaturation temperature (T(d)) was heating-rate dependent. The T(d) value decreased by about 4 °C by lowering the heating rate from 10 to 5 °C/min. The SDS-PAGE analysis revealed that protein denaturation upon heating at 90 °C was mainly governed by noncovalent interaction. The SEC-HPLC measurements indicated that low-denatured legumin (≈350-410 kDa) and vicilin/convicilin (≈170 kDa) globulins were heat-denatured and most of their subunits reassociated int…
Effect of pea proteins extraction and vicilin/legumin fractionation on the phase behavior in admixture with alginate
Abstract Soluble and natural mixed pea proteins (PP) were extracted from defatted pea seeds according to acidic precipitation (PPP) or ultrafiltration/diafiltration (PPDF) procedures. The isolates contained proteins with a low level of denaturation. Mixed pea globulins isolates presented quite similar solubility and thermal profiles, also a similar polypeptide composition. Vicilin/convicilin 7S (Vic) and legumin 11S (Leg) fractions were obtained by batch chromatography using a salt gradient for the elution. Several incompatible systems were built by mixing the pea proteins with an anionic polysaccharide (sodium alginate, SA), when biopolymers were both negatively charged. Most of mixtures e…
Protein aggregation induced by phase separation in a pea proteins–sodium alginate–water ternary system
Abstract The physicochemical properties of a native, globular plant protein–linear anionic polysaccharide aqueous system at 20 °C were investigated in conditions where biopolymers carry a net negative charge (pH 7.2, 0.1 M NaCl). The pea proteins–sodium alginate mixtures showed a phase separation mainly by thermodynamic incompatibility, characterized at both the macroscopic and microscopic scale. Phase diagram was established and confocal laser scanning microscopy (CLSM) provided accurate data on the microstructure morphology of the system, regarding its phase behavior. In admixture, sodium alginate induced a protein aggregation, certainly by a local depletion of the polysaccharide. Protein…
Partition of volatile compounds in pea globulin–maltodextrin aqueous two-phase system
International audience; This study is based on the assumption that the off-flavour of pea proteins might be decreased using the retention of volatile compounds by a mixture with another biopolymer. The partition of volatile compounds in an aqueous system containing pea protein and maltodextrins was followed under thermodynamic incompatibility conditions. Firstly, the phase diagram of the system was established. Then, the partition of aroma compounds between the phase rich in protein and the phase rich in maltodextrin was measured by SPME–GC–MS. There was a transfer of volatile compounds during phase separation. Variations of pH were also used to vary the retention of volatile compounds by p…
The effects of sodium alginate and calcium levels on pea proteins cold-set gelation
Abstract A multi-scale investigation of pea proteins – alginate cold-set gels was proposed in this study. The gel preparation followed a two-steps procedure. Globular pea proteins were first denatured and aggregated by a pre-heating step. Sodium alginate was then added at different concentrations. Thereafter the in situ gelation process was induced at 20 °C using glucono-δ-lactone (GDL) and two calcium carbonate (CC) levels; calcium cations were released as the pH decreased. Small-amplitude rheology measurements (storage modulus G′) showed that stronger mixed gels were obtained than single-biopolymer solutions. Confocal laser scanning microscopy (CLSM) revealed phase-separating microstructu…
Formulation, process conditions, and biological evaluation of dairy mixed gels containing fava bean and milk proteins: Effect on protein retention in growing young rats
International audience; Food formulation and process conditions can indirectly influence AA digestibility and bioavailability. Here we investigated the effects of formulation and process conditions used in the manufacture of novel blended dairy gels (called "mixed gels" here) containing fava bean (Vicia faba) globular proteins on both protein composition and metabolism when given to young rats. Three mixed dairy gels containing casein micelles and fava bean proteins were produced either by chemical acidification (A) with glucono-δ-lactone (GDL) or by lactic acid fermentation. Fermented gels containing casein and fava bean proteins were produced without (F) or with (FW) whey proteins. The AA…
Formulation et procédés de fabrication des gels laitiers enrichis en globulines de fèverole : Impact sur la rétention protéique chez les rats jeunes en croissance
Introduction et but de l’etude L’impact environnemental et les risques pour la sante associes a la production et la consommation excessive de sources de proteines animales pourraient etre limites par l’augmentation de la part des proteines vegetales dans notre alimentation. Les proteines vegetales sont parfois deficitaires en certains acides amines (AA) essentiels. De ce fait, un melange de proteines animales et vegetales permettrait d’assurer une complementarite en AA repondant aux besoins de l’organisme. L’objectif de cette etude etait d’evaluer l’impact, sur la taille des proteines, de la formulation et des processus de transformation des gels laitiers enrichis en legumineuses et d’etudi…
Formulation et procédés de fabrication des gels laitiers enrichis en globulines de fèverole :Impact sur la rétention protéique chez les rats jeunes en croissance
Introduction et but de l’étude : L’impact environnemental et les risques pour la santé associés à la production et la consommation excessive de sources de protéines animales pourraient être limités par l’augmentation de la part des protéines végétales dans notre alimentation. Les protéines végétales sont parfois déficitaires en certains acides aminés (AA) essentiels. De ce fait, un mélange de protéines animales et végétales permettrait d’assurer une complémentarité en AA répondant aux besoins de l’organisme. L'objectif de cette étude était d'évaluer l'impact, sur la taille des protéines, de la formulation et des processus de transformation des gels laitiers enrichis en légumineuses et d’étu…