Scaling Properties of Gelling Systems in Nonlinear Shear Experiments.

We study model near-critical polymer gelling systems made of gluten protein dispersions stabilized at different distances from the gel point. We impose different shear rates and follow the time evolution of the stress. For sufficiently large shear rates, an intermediate stress overshoot is measured before reaching the steady state.

protein digestibility of RuBisCO-enriched wheat dough: a comparative study with pea and gluten proteins.

Growing demand for sustainable, plant-based protein sources has stimulated interest in new ingredients for food enrichment. This study investigates the nutritional and digestive implications of enriching wheat dough with RuBisCO, in comparison to pea protein-enriched and gluten-enriched doughs. The protein quality and digestibility of these enriched doughs were analysed through dough characterization, digestion experiments and biochemical analysis of digesta.

Investigating sorghum protein solubility and in vitro digestibility during seed germination.

In this work, we examined the impact of sorghum gain germination on kafirins solubility and digestibility. Two genotypes differing in their proteins and tannins contents were germinated under controlled conditions up to radicle emergence. Biochemical, physicochemical, and in vitro digestibility tests were applied on the germinated grains.

Sorghum grain germination as a route to improve kafirin digestibility: Biochemical and label free proteomics insights.

Kafirin, the sorghum grain storage protein presents lower digestibility compared to its cereals counterparts. Germination has been proposed as an adequate bioprocessing method to improve seed protein digestibility. Here, germination was rationalized so as to evenly sample germinated seeds and the dynamic changes of the proteome and several biochemical markers was connected for the first time with the in vitro protein digestibility of germinated seeds.

Biochemical and physical-chemical characterisation of leaf proteins extracted from Cichorium endivia leaves.

This study provides a detailed characterisation of a leaf protein concentrate (LPC) extracted from Cichorium endivia leaves using a pilot scale process. This concentrate contains 74.1% protein and is mainly composed of Ribulose-1,5-BISphosphate Carboxylase/Oxygenase (RuBisCO).

Effect of extrusion and turmeric addition on phenolic compounds and kafirin properties in tannin and tannin-free sorghum.

Sorghum is a potential substitute for corn/wheat in cereal-based extruded products. Despite agronomic advantages and its rich diversity of phenolic compounds, sorghum kafirins group together and form complex with tannins, leading to a low digestibility. Phenolic content/profile by UPLC-ESI-QTOF-MS and kafirins polymerization by SE-HPLC were evaluated in wholemeal sorghum extrudates; tannin-rich (#SC319) and tannin-free (#BRS330) genotypes with/without turmeric powder.

Impact of the protein composition on the structure and viscoelasticity of polymer-like gluten gels.

We investigate the structure of gluten polymer-like gels in a binary mixture of water/ethanol, 50/50 v/v, a good solvent for gluten proteins. Gluten comprises two main families of proteins, monomeric gliadins and polymer glutenins. In the semi-dilute regime, scattering experiments highlight two classes of behavior, akin to standard polymer solution and polymer gel, depending on the protein composition.

N Partitioning between Gluten Fractions in a Set of Italian Durum Wheat Cultivars: Role of the Grain N Content.

Grain protein content constitutes a key quality trait for durum wheat end-products and may also impact grain protein composition. A total of sixteen durum wheat cultivars were analyzed in a field trial during two seasons at two nitrogen (N) levels to evaluate whether and to what extent the variation in total grain N was associated with variation in the quantity of the various protein fractions and grain quality parameters. Genotypic variation in grain N content correlated with the variation in the content of all three protein fractions, although the strength of the correlation with gliadin and albumin-globulin was higher than that with glutenins.

Phase separation dynamics of gluten protein mixtures.

We investigate by time-resolved synchrotron ultra-small X-ray scattering the dynamics of liquid-liquid phase-separation (LLPS) of gluten protein suspensions following a temperature quench. Samples at a fixed concentration (237 mg ml) but with different protein compositions are investigated. In our experimental conditions, we show that fluid viscoelastic samples depleted in polymeric glutenin phase-separate following a spinodal decomposition process.

Dynamics of liquid-liquid phase separation of wheat gliadins.

During wheat seeds development, storage proteins are synthetized and subsequently form dense protein phases, also called Protein Bodies (PBs). The mechanisms of PBs formation and the supramolecular assembly of storage proteins in PBs remain unclear. In particular, there is an apparent contradiction between the low solubility in water of storage proteins and their high local dynamics in dense PBs.

Fate of SDS-insoluble glutenin polymers from semolina to dry pasta.

Pasta cooking quality is well known to be related to semolina protein content and composition, however impact of the unextractable polymeric protein content (%UPP) remains disputed. In this work different semolina samples, of variable protein contents (10.5-14.

Responses to Hypoxia and Endoplasmic Reticulum Stress Discriminate the Development of Vitreous and Floury Endosperms of Conventional Maize () Inbred Lines.

Major nutritional and agronomical issues relating to maize () grains depend on the vitreousness/hardness of its endosperm. To identify the corresponding molecular and cellular mechanisms, most studies have been conducted on opaque/floury mutants, and recently on Quality Protein Maize, a reversion of an mutation by modifier genes. These mutant lines are far from conventional maize crops.

Osmotic compression of anisotropic proteins: interaction properties and associated structures in wheat gliadin dispersions.

In this Article, we investigated the interaction properties of wheat gliadins, properties that are at the basis of their functionality in wheat grain and in food matrixes. We established the equation of state of our isolate by osmotic compression and characterized the concentration-induced structural transitions, from the secondary structure of proteins to the rheological properties. We evidenced three thermodynamical regimes corresponding to several structuring regimes.

Lipid partitioning in maize (Zea mays L.) endosperm highlights relationships among starch lipids, amylose, and vitreousness.

Content and composition of maize endosperm lipids and their partition in the floury and vitreous regions were determined for a set of inbred lines. Neutral lipids, i.e.

Polymeric assembly of gluten proteins in an aqueous ethanol solvent.

The supramolecular organization of wheat gluten proteins is largely unknown due to the intrinsic complexity of this family of proteins and their insolubility in water. We fractionate gluten in a water/ethanol mixture (50/50 v/v) and obtain a protein extract which is depleted in gliadin, the monomeric part of wheat gluten proteins, and enriched in glutenin, the polymeric part of wheat gluten proteins. We investigate the structure of the proteins in the solvent used for extraction over a wide range of concentration, by combining X-ray scattering and multiangle static and dynamic light scattering.

Retention and release of cinnamaldehyde from wheat protein matrices.

Cinnamaldehyde treatment of gliadin films provided a means of decreasing their solubility, increasing their molecular weight profile, and reducing their overall migration into food simulants as a consequence of the high degree of polymerization achieved. Despite losses incurred in the film manufacturing process, and the amount that remained covalently bonded with protein because of cross-linking, the addition of 1.5, 3, and 5% of cinnamaldehyde (g/100 g protein) to gliadins at pH 2 rendered 1.

Relationship between endosperm cells redox homeostasis and glutenin polymers assembly in developing durum wheat grain.

Assembly of glutenin polymers was examined for two contrasted durum wheat cultivars in connection with changes in the redox status of the endosperm cells that accompanied grain development. The evolutions of the redox state of ascorbate and glutathione, as well as the activities of antioxidant enzymes were measured. Changes in the size distribution profile and redox state of storage proteins were evaluated, with particular emphasis on protein-bound glutathione (PSSG).

Mechanisms of heat-mediated aggregation of wheat gluten protein upon pasta processing.

During pasta processing, structural changes of protein occur, due to changes in water content, mechanical energy input, and high temperature treatments. The present paper investigates the impact of successive and intense thermal treatments (high temperature drying, cooking, and overcooking) on aggregation of gluten protein in pasta. Protein aggregation was evaluated by the measurement of sensitivity of disulfide bonds toward reduction with dithioerythritol (DTE), at different reactions times.

Interactions of Kraft lignin and wheat gluten during biomaterial processing: evidence for the role of phenolic groups.

The chemical interactions between Kraft lignin and wheat gluten under processing conditions were investigated by determining the extent of the protein network formation. To clarify the role of different chemical functions found in lignin, the effect of Kraft lignin was compared with that of an esterified lignin, in which hydroxyl groups had been suppressed by esterification, and with a series of simple aromatics and phenolic structures with different functionalities (conjugated double bonds, hydroxyl, carboxylic acid, and aldehyde). The protein solubility was determined by using the Kjeldahl method.

Modification of the wheat gluten network by Kraft lignin addition.

The effect of Kraft lignin (KL) on wheat gluten (WG) network formation during biomaterial processing was investigated. Gluten plasticized with glycerol was blended with a variable content of KL and processed into material by mixing and hot molding. The effect of KL on WG cross-linking was assessed by size-exclusion chromatography coupled with specific detection of KL by fluorescence.

Characterization of natural rubber using size-exclusion chromatography with online multi-angle light scattering. Study of the phenomenon behind the abnormal elution profile.

Natural and synthetic poly(cis-1,4-isoprene) were characterized by size-exclusion chromatography coupled with an online multi-angle light scattering detector (SEC-MALS). Unlike synthetic poly(cis-1,4-isoprene) (SR), natural rubber (NR) samples showed anomalous elution profiles. The beginning of elution was very similar to SR but, after a certain elution volume, the molar masses of the eluting macromolecules increased with elution volume instead of continuing to decrease, which resulted in an upturn curve profile.

Effects of laccase and xylanase on the chemical and rheological properties of oat and wheat doughs.

The effects of Trametes hirsuta laccase and Pentopan Mono BG xylanase and their combination on oat, wheat, and mixed oat-wheat doughs and the corresponding breads were investigated. Laccase treatment decreased the content of water-extractable arabinoxylan (WEAX) in oat dough due to oxidative cross-linking of feruloylated arabinoxylans. Laccase treatment also increased the proportion of water-soluble polysaccharides (WSNSP) apparently due to the beta-glucanase side activity present in the laccase preparation.

Reactivity of wheat gluten protein during mechanical mixing: radical and nucleophilic reactions for the addition of molecules on sulfur.

Mechanical properties of gluten-based biomaterials, such as break stress, were known to be influenced by temperature and shear stresses applied during processing. It is well documented in literature that these processing parameters promoted wheat gluten protein aggregation. Exchange between disulfide bonds and thiol groups oxidation are the postulated mechanisms that lead to gluten protein solubility loss in sodium dodecyl sulfate buffers.

Impact of protein size distribution on gluten thermal reactivity and functional properties.

Wheat gluten structure was modified in different ways: Disulfide bonds were reduced by sulfitolysis, or protein chains were enzymatically hydrolyzed at three different degrees of proteolysis. A kinetic study of the thermal reactivity of the modified glutens showed that gluten aggregation kinetic was slowed in consequence to the shift of gluten size distribution toward smaller proteins. In contrary to sulfitolysis, proteolysis also affected the gluten reactivity potential because of the formation of numerous nonreactive species.