The Experts below are selected from a list of 207 Experts worldwide ranked by ideXlab platform
Thomas Croguennec - One of the best experts on this subject based on the ideXlab platform.
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the repartition of whey protein microgels and caseins between Fat Droplet surface and the continuous phase governs the heat stability of emulsions
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2019Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Chantal Cauty, Pascaline Hamon, Florence Rousseau, Jonathan Thevenot, Thomas CroguennecAbstract:Abstract Whey protein microgels (WPM) are highly stable on heating and form Pickering-like emulsions exhibiting long-term resistance to coalescence. However, the heat stability of WPM emulsions is unclear and depends on the emulsion characteristics (WPM concentration, presence of non-microgel proteins such as caseins). The objective of this study was to investigate the heat-stability of WPM emulsions in the presence of caseins in order to clarify the role of the two types of proteins in the mechanism of heat-stabilization/destabilization. Emulsions (30 wt% milkFat) containing WPM (from 2.34 to 6.84 wt%) and non-microgel proteins, mainly caseins (from 0 to 0.81 wt%), were prepared at pH 7. A comparison of the emulsions before and after heating at 120 °C up to 30 min allowed their classification in three categories: viscous emulsions that gelled on heating (emulsions E1), fluid emulsions that gelled on heating (emulsions E2) and fluid emulsions even after heating (emulsion E3). A characterization of the Fat Droplet surface (protein interfacial load, protein composition, structure of the adsorbed entities by transmission electron microscopy) indicated emulsions E1 and E2 had WPM adsorbed at the Fat Droplet surface but their structural rearrangement did not explain the heat-induced modifications. Emulsions E3 had a Fat Droplet interfacial layer composed of caseins whereas the WPM were only located in the continuous phase. These results demonstrate that the WPM do not contribute to emulsion heat-stability but they do not induce heat instability as long as they are not situated at the Fat Droplet interface. Knowing the total interfacial area, the amount of caseins to obtain heat stable emulsions containing WPM can be evaluated because the caseins dominate WPM adsorption at the Fat Droplet surface. This knowledge will allow controlling the stability of dairy emulsions in a wider whey protein concentration range than when using native whey proteins.
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Increasing the heat stability of whey protein-rich emulsions by combining the functional role of WPM and caseins
Food Hydrocolloids, 2018Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Pascaline Hamon, Florence Rousseau, Jonathan Thevenot, Thomas CroguennecAbstract:Abstract The heat stability of whey protein emulsions remains a real challenge due to the rapid denaturation/aggregation of native whey proteins on heating. The use of heat-stable Pickering-like whey protein microgels (WPM) makes it possible to develop heat-stable emulsions in a large range of whey protein concentrations. In this study, emulsion heat stability was evaluated with a special focus on the contribution of WPM adsorbed at the Fat Droplet surface and in the continuous phase of the emulsion. Dairy emulsions were prepared with 30% milk Fat and 70% suspension of WPM in the dispersed phase of milk. The protein interfacial load and the composition of the Fat Droplet surface were determined immediately after emulsion formation, and the heat stability of the emulsions at 120 °C was assessed visually and at microscopic scale. WPM are heat stable in the continuous phase of the emulsion, but the presence of WPM at the surface of the Fat Droplets is responsible for a rapid gelation of the emulsions. In the heated emulsions, the Fat Droplets seemed to be crosslinked by WPM. The presence of caseins instead of WPM at the Fat Droplet surface allowed the heat stability of the emulsion to recover at low and high whey protein concentrations. This study shows that it is possible to prepare heat-stable whey protein–rich emulsions by using whey proteins previously aggregated as heat-stable WPM and a sufficient amount of caseins in order to fully cover the Fat Droplet surface. These results will contribute to the development of heat-stable whey protein–rich emulsions.
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aggregated whey proteins and trace of caseins synergistically improve the heat stability of whey protein rich emulsions
Food Hydrocolloids, 2016Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Pascaline Hamon, Florence Rousseau, Thomas CroguennecAbstract:Abstract Heat treatments are used to extend the shelf life of manufactured food emulsions, which in turn require excellent heat stability. Whey protein aggregation prior to homogenization is a means to modify emulsion heat stability but the underlying mechanism of heat stabilization has hardly been studied in an industrial context where whey protein ingredients contain caseins. Emulsions were prepared with 30% anhydrous milk Fat and 70% whey protein/casein solutions with protein concentrations ranging from 3 to 6%. The proteins were either unheated (WP/Cas samples) or heat-aggregated (A-WP/Cas samples). After homogenization, the Fat Droplet interface was characterized and emulsion stability was analyzed visually and at microscopic level. WP/Cas emulsions were heat stable at low protein concentrations but exhibited a gradual decrease in heat stability when the protein concentration increased (>3%). This instability was due to the co-gelation of the protein-coated Fat Droplets and the proteins in the dispersing phase. In contrast, A-WP/Cas emulsions were rapidly heat destabilized at low protein concentrations (
David Julian Mcclements - One of the best experts on this subject based on the ideXlab platform.
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structural design approaches for creating Fat Droplet and starch granule mimetics
Food & Function, 2017Co-Authors: David Julian Mcclements, Cheryl Chung, Bicheng WuAbstract:This article focuses on hydrogel-based strategies for creating reduced calorie foods with desirable physicochemical, sensory, and nutritional properties. Initially, the role of Fat Droplets and starch granules in foods is discussed, and then different methods for fabricating hydrogel beads are reviewed, including phase separation, antisolvent precipitation, injection, and emulsion template methods. Finally, the potential application of hydrogel beads as Fat Droplet and starch granule replacements is discussed. There is still a need for large-scale, high-throughout, and economical methods of fabricating hydrogel beads suitable for utilization within the food industry.
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design of reduced Fat food emulsions manipulating microstructure and rheology through controlled aggregation of colloidal particles and biopolymers
Food Research International, 2015Co-Authors: Bicheng Wu, David Julian McclementsAbstract:The objective of this study was to develop model reduced-calorie food emulsions with desirable textural and optical properties based on controlled aggregation of food-grade colloidal particles and biopolymers. The model food emulsion consisted of Fat Droplets (5wt.%), starch granules (4wt.%), and xanthan gum (0 to 0.02wt.%) under acidic conditions (pH3). The Fat Droplets were stabilized by a protein-based emulsifier (whey protein isolate). Fat Droplet aggregation was induced by adding anionic xanthan gum to promote bridging flocculation of the cationic protein-coated Fat Droplets. Thermal processing (95°C) did not have a major impact on Fat Droplet aggregation, but it did promote starch granule swelling. The structural organization of the Fat Droplets could be regulated by altering xanthan levels. Relatively small Droplet aggregates were formed at low xanthan concentrations that coated the starch granule surfaces. Conversely, large irregular shaped Droplet aggregates were formed throughout the system at higher xanthan levels. The rheological and optical properties of the model emulsions could therefore be controlled by altering Fat Droplet organization. Addition of low levels of xanthan significantly increased the viscosity, yield stress, and complex modulus of the model food emulsions. However, high levels of xanthan led to the formation of large visible aggregates that would negatively impact on sensory quality. This study has important implications for the development of cost-effective and clean-label reduced-Fat products with desirable quality attributes, such as dressings and sauces.
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understanding multicomponent emulsion based products influence of locust bean gum on Fat Droplet starch granule mixtures
Food Hydrocolloids, 2014Co-Authors: Cheryl Chung, Brian Degner, David Julian McclementsAbstract:Abstract The influence of composition and microstructure on the physicochemical properties of model food emulsions containing Fat Droplets, starch granules, and hydrocolloids was studied. These multicomponent model systems consisted of 5% protein-coated Fat Droplets, 3.75% modified starch, and 0–1% locust bean gum (LBG) and could be characterized as non-ideal plastics that exhibited shear-thinning behavior. The gelatinized starch granules played the most important role in determining the overall rheology of the mixed systems because of their relatively high effective volume fraction (∼38%), but the Fat Droplets and hydrocolloid also played an important role. The apparent viscosity (at 10 s −1 ) and yield stress of the mixed systems increased with increasing LBG concentration. The Fat Droplets and starch granules played the most important role in determining the lightness of the mixed systems, with changes in LBG concentration having little impact on the overall optical properties. This research provides some important information about the influence of hydrocolloids on the properties of multicomponent model emulsions, which may be useful in the development of reduced-Fat foods with desirable sensory properties.
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Understanding multicomponent emulsion-based products: Influence of locust bean gum on Fat Droplet – Starch granule mixtures
Food Hydrocolloids, 2014Co-Authors: Cheryl Chung, Brian Degner, David Julian McclementsAbstract:Abstract The influence of composition and microstructure on the physicochemical properties of model food emulsions containing Fat Droplets, starch granules, and hydrocolloids was studied. These multicomponent model systems consisted of 5% protein-coated Fat Droplets, 3.75% modified starch, and 0–1% locust bean gum (LBG) and could be characterized as non-ideal plastics that exhibited shear-thinning behavior. The gelatinized starch granules played the most important role in determining the overall rheology of the mixed systems because of their relatively high effective volume fraction (∼38%), but the Fat Droplets and hydrocolloid also played an important role. The apparent viscosity (at 10 s −1 ) and yield stress of the mixed systems increased with increasing LBG concentration. The Fat Droplets and starch granules played the most important role in determining the lightness of the mixed systems, with changes in LBG concentration having little impact on the overall optical properties. This research provides some important information about the influence of hydrocolloids on the properties of multicomponent model emulsions, which may be useful in the development of reduced-Fat foods with desirable sensory properties.
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creation of reduced Fat foods influence of calcium induced Droplet aggregation on microstructure and rheology of mixed food dispersions
Food Chemistry, 2013Co-Authors: Bicheng Wu, Brian Degner, David Julian McclementsAbstract:Abstract The impact of calcium-induced Fat Droplet aggregation on the microstructure and physicochemical properties of model mixed colloidal dispersions was investigated. These systems consisted of 2 wt% whey protein-coated Fat Droplets and 4 wt% modified starch granules heated to induce starch swelling (pH 7). Optical and confocal microscopy showed that the Fat Droplets were dispersed within the interstitial region between the swollen starch granules. The structural organisation of the Fat Droplets within these interstitial regions could be modulated by controlling the calcium concentration: (i) at a low calcium concentration the Droplets were evenly distributed; (ii) at an intermediate calcium concentration they formed a layer around the starch granules; (iii) at a high calcium concentration they formed a network of aggregated Droplets. Paste-like materials were produced when the Fat Droplets formed a three-dimensional network in the interstitial region. The properties of Fat Droplet–starch granule suspensions can be modulated by altering the electrostatic interactions to alter microstructure.
Alain Riaublanc - One of the best experts on this subject based on the ideXlab platform.
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the repartition of whey protein microgels and caseins between Fat Droplet surface and the continuous phase governs the heat stability of emulsions
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2019Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Chantal Cauty, Pascaline Hamon, Florence Rousseau, Jonathan Thevenot, Thomas CroguennecAbstract:Abstract Whey protein microgels (WPM) are highly stable on heating and form Pickering-like emulsions exhibiting long-term resistance to coalescence. However, the heat stability of WPM emulsions is unclear and depends on the emulsion characteristics (WPM concentration, presence of non-microgel proteins such as caseins). The objective of this study was to investigate the heat-stability of WPM emulsions in the presence of caseins in order to clarify the role of the two types of proteins in the mechanism of heat-stabilization/destabilization. Emulsions (30 wt% milkFat) containing WPM (from 2.34 to 6.84 wt%) and non-microgel proteins, mainly caseins (from 0 to 0.81 wt%), were prepared at pH 7. A comparison of the emulsions before and after heating at 120 °C up to 30 min allowed their classification in three categories: viscous emulsions that gelled on heating (emulsions E1), fluid emulsions that gelled on heating (emulsions E2) and fluid emulsions even after heating (emulsion E3). A characterization of the Fat Droplet surface (protein interfacial load, protein composition, structure of the adsorbed entities by transmission electron microscopy) indicated emulsions E1 and E2 had WPM adsorbed at the Fat Droplet surface but their structural rearrangement did not explain the heat-induced modifications. Emulsions E3 had a Fat Droplet interfacial layer composed of caseins whereas the WPM were only located in the continuous phase. These results demonstrate that the WPM do not contribute to emulsion heat-stability but they do not induce heat instability as long as they are not situated at the Fat Droplet interface. Knowing the total interfacial area, the amount of caseins to obtain heat stable emulsions containing WPM can be evaluated because the caseins dominate WPM adsorption at the Fat Droplet surface. This knowledge will allow controlling the stability of dairy emulsions in a wider whey protein concentration range than when using native whey proteins.
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Increasing the heat stability of whey protein-rich emulsions by combining the functional role of WPM and caseins
Food Hydrocolloids, 2018Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Pascaline Hamon, Florence Rousseau, Jonathan Thevenot, Thomas CroguennecAbstract:Abstract The heat stability of whey protein emulsions remains a real challenge due to the rapid denaturation/aggregation of native whey proteins on heating. The use of heat-stable Pickering-like whey protein microgels (WPM) makes it possible to develop heat-stable emulsions in a large range of whey protein concentrations. In this study, emulsion heat stability was evaluated with a special focus on the contribution of WPM adsorbed at the Fat Droplet surface and in the continuous phase of the emulsion. Dairy emulsions were prepared with 30% milk Fat and 70% suspension of WPM in the dispersed phase of milk. The protein interfacial load and the composition of the Fat Droplet surface were determined immediately after emulsion formation, and the heat stability of the emulsions at 120 °C was assessed visually and at microscopic scale. WPM are heat stable in the continuous phase of the emulsion, but the presence of WPM at the surface of the Fat Droplets is responsible for a rapid gelation of the emulsions. In the heated emulsions, the Fat Droplets seemed to be crosslinked by WPM. The presence of caseins instead of WPM at the Fat Droplet surface allowed the heat stability of the emulsion to recover at low and high whey protein concentrations. This study shows that it is possible to prepare heat-stable whey protein–rich emulsions by using whey proteins previously aggregated as heat-stable WPM and a sufficient amount of caseins in order to fully cover the Fat Droplet surface. These results will contribute to the development of heat-stable whey protein–rich emulsions.
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aggregated whey proteins and trace of caseins synergistically improve the heat stability of whey protein rich emulsions
Food Hydrocolloids, 2016Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Pascaline Hamon, Florence Rousseau, Thomas CroguennecAbstract:Abstract Heat treatments are used to extend the shelf life of manufactured food emulsions, which in turn require excellent heat stability. Whey protein aggregation prior to homogenization is a means to modify emulsion heat stability but the underlying mechanism of heat stabilization has hardly been studied in an industrial context where whey protein ingredients contain caseins. Emulsions were prepared with 30% anhydrous milk Fat and 70% whey protein/casein solutions with protein concentrations ranging from 3 to 6%. The proteins were either unheated (WP/Cas samples) or heat-aggregated (A-WP/Cas samples). After homogenization, the Fat Droplet interface was characterized and emulsion stability was analyzed visually and at microscopic level. WP/Cas emulsions were heat stable at low protein concentrations but exhibited a gradual decrease in heat stability when the protein concentration increased (>3%). This instability was due to the co-gelation of the protein-coated Fat Droplets and the proteins in the dispersing phase. In contrast, A-WP/Cas emulsions were rapidly heat destabilized at low protein concentrations (
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modelling the formation of Fat Droplet interface during homogenisation in order to describe the texture
Procedia food science, 2011Co-Authors: Julie Foucquier, Alain Riaublanc, Sebastien Gaucel, Claire Surel, Cedric Baudrit, Nathalie PerrotAbstract:Abstract The homogenisation is an important operation in the dairy product processes, characterised by disruption of Fat globules and then, coalescence between Fat Droplets and adsorption of milk proteins (monomers, polymers and aggregates of proteins) and other surfactants on Fat Droplet surface. Moreover, the homogenisation has often an impact on the textural properties of the products. In the literature, there are some articles dealing with the modelling of the phenomena occurring during the homogenisation. The aim of this work is to express some properties of the texture of the product from the structure. However, the models existing in the literature characterise the structure at a too fine scale to be linked to the texture. Consequently, we attempt to implement a mathematical model able to describe the interface of Fat Droplets during homogenisation at a mesoscopic scale involving texture. The approach consists in coupling models for the formation of the interface of Fat Droplets with an expert model to obtain the texture of the product, leading to an integrated knowledge model. This paper focuses on the model of formation of interface of Fat Droplets, using a mechanistic approach built from literature, expert knowledge and measurements and the qualitative is performed. Afterwards, an expert model, non deterministic, will be built with the output of the mechanistic model and the expert knowledge.
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influence of Fat globule membrane composition on water holding capacity and water mobility in casein rennet gel a nuclear magnetic resonance self diffusion and relaxation study
International Dairy Journal, 2006Co-Authors: Angelique Metais, Alain Riaublanc, Mireille Cambert, Francois MarietteAbstract:The effects of the composition of the Fat globule surface on water holding capacity and water diffusion were studied in different rennet-derived retentates. Water holding capacity was determined from nuclear magnetic resonance (NMR) relaxation measurements; the water diffusion coefficient was estimated using Pulse Field Gradient NMR. Reconstituted Fatty retentates were prepared from Fat-free retentate mixed with different Fat-in-water emulsions stabilized with native phosphocaseinates (NPCs) or sodium caseinates. Coagulation of retentate reconstituted with native Fat globules (fresh cream) and of industrial Fatty retentate was also investigated. The study showed that the Fat Droplet/water interface influenced the water diffusion coefficient in the cream-reconstituted retentate gel only. No effect was observed in the NPC- and Na-caseinate-reconstituted retentate and in the Fatty industrial retentate after coagulation. The results of the relaxation measurements in the gelled Fatty reconstituted retentates showed that the nature and the composition of the Fat interface influence the syneresis behaviour.
Marie Chevallier - One of the best experts on this subject based on the ideXlab platform.
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the repartition of whey protein microgels and caseins between Fat Droplet surface and the continuous phase governs the heat stability of emulsions
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2019Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Chantal Cauty, Pascaline Hamon, Florence Rousseau, Jonathan Thevenot, Thomas CroguennecAbstract:Abstract Whey protein microgels (WPM) are highly stable on heating and form Pickering-like emulsions exhibiting long-term resistance to coalescence. However, the heat stability of WPM emulsions is unclear and depends on the emulsion characteristics (WPM concentration, presence of non-microgel proteins such as caseins). The objective of this study was to investigate the heat-stability of WPM emulsions in the presence of caseins in order to clarify the role of the two types of proteins in the mechanism of heat-stabilization/destabilization. Emulsions (30 wt% milkFat) containing WPM (from 2.34 to 6.84 wt%) and non-microgel proteins, mainly caseins (from 0 to 0.81 wt%), were prepared at pH 7. A comparison of the emulsions before and after heating at 120 °C up to 30 min allowed their classification in three categories: viscous emulsions that gelled on heating (emulsions E1), fluid emulsions that gelled on heating (emulsions E2) and fluid emulsions even after heating (emulsion E3). A characterization of the Fat Droplet surface (protein interfacial load, protein composition, structure of the adsorbed entities by transmission electron microscopy) indicated emulsions E1 and E2 had WPM adsorbed at the Fat Droplet surface but their structural rearrangement did not explain the heat-induced modifications. Emulsions E3 had a Fat Droplet interfacial layer composed of caseins whereas the WPM were only located in the continuous phase. These results demonstrate that the WPM do not contribute to emulsion heat-stability but they do not induce heat instability as long as they are not situated at the Fat Droplet interface. Knowing the total interfacial area, the amount of caseins to obtain heat stable emulsions containing WPM can be evaluated because the caseins dominate WPM adsorption at the Fat Droplet surface. This knowledge will allow controlling the stability of dairy emulsions in a wider whey protein concentration range than when using native whey proteins.
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Increasing the heat stability of whey protein-rich emulsions by combining the functional role of WPM and caseins
Food Hydrocolloids, 2018Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Pascaline Hamon, Florence Rousseau, Jonathan Thevenot, Thomas CroguennecAbstract:Abstract The heat stability of whey protein emulsions remains a real challenge due to the rapid denaturation/aggregation of native whey proteins on heating. The use of heat-stable Pickering-like whey protein microgels (WPM) makes it possible to develop heat-stable emulsions in a large range of whey protein concentrations. In this study, emulsion heat stability was evaluated with a special focus on the contribution of WPM adsorbed at the Fat Droplet surface and in the continuous phase of the emulsion. Dairy emulsions were prepared with 30% milk Fat and 70% suspension of WPM in the dispersed phase of milk. The protein interfacial load and the composition of the Fat Droplet surface were determined immediately after emulsion formation, and the heat stability of the emulsions at 120 °C was assessed visually and at microscopic scale. WPM are heat stable in the continuous phase of the emulsion, but the presence of WPM at the surface of the Fat Droplets is responsible for a rapid gelation of the emulsions. In the heated emulsions, the Fat Droplets seemed to be crosslinked by WPM. The presence of caseins instead of WPM at the Fat Droplet surface allowed the heat stability of the emulsion to recover at low and high whey protein concentrations. This study shows that it is possible to prepare heat-stable whey protein–rich emulsions by using whey proteins previously aggregated as heat-stable WPM and a sufficient amount of caseins in order to fully cover the Fat Droplet surface. These results will contribute to the development of heat-stable whey protein–rich emulsions.
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aggregated whey proteins and trace of caseins synergistically improve the heat stability of whey protein rich emulsions
Food Hydrocolloids, 2016Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Pascaline Hamon, Florence Rousseau, Thomas CroguennecAbstract:Abstract Heat treatments are used to extend the shelf life of manufactured food emulsions, which in turn require excellent heat stability. Whey protein aggregation prior to homogenization is a means to modify emulsion heat stability but the underlying mechanism of heat stabilization has hardly been studied in an industrial context where whey protein ingredients contain caseins. Emulsions were prepared with 30% anhydrous milk Fat and 70% whey protein/casein solutions with protein concentrations ranging from 3 to 6%. The proteins were either unheated (WP/Cas samples) or heat-aggregated (A-WP/Cas samples). After homogenization, the Fat Droplet interface was characterized and emulsion stability was analyzed visually and at microscopic level. WP/Cas emulsions were heat stable at low protein concentrations but exhibited a gradual decrease in heat stability when the protein concentration increased (>3%). This instability was due to the co-gelation of the protein-coated Fat Droplets and the proteins in the dispersing phase. In contrast, A-WP/Cas emulsions were rapidly heat destabilized at low protein concentrations (
Christelle Lopez - One of the best experts on this subject based on the ideXlab platform.
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the repartition of whey protein microgels and caseins between Fat Droplet surface and the continuous phase governs the heat stability of emulsions
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2019Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Chantal Cauty, Pascaline Hamon, Florence Rousseau, Jonathan Thevenot, Thomas CroguennecAbstract:Abstract Whey protein microgels (WPM) are highly stable on heating and form Pickering-like emulsions exhibiting long-term resistance to coalescence. However, the heat stability of WPM emulsions is unclear and depends on the emulsion characteristics (WPM concentration, presence of non-microgel proteins such as caseins). The objective of this study was to investigate the heat-stability of WPM emulsions in the presence of caseins in order to clarify the role of the two types of proteins in the mechanism of heat-stabilization/destabilization. Emulsions (30 wt% milkFat) containing WPM (from 2.34 to 6.84 wt%) and non-microgel proteins, mainly caseins (from 0 to 0.81 wt%), were prepared at pH 7. A comparison of the emulsions before and after heating at 120 °C up to 30 min allowed their classification in three categories: viscous emulsions that gelled on heating (emulsions E1), fluid emulsions that gelled on heating (emulsions E2) and fluid emulsions even after heating (emulsion E3). A characterization of the Fat Droplet surface (protein interfacial load, protein composition, structure of the adsorbed entities by transmission electron microscopy) indicated emulsions E1 and E2 had WPM adsorbed at the Fat Droplet surface but their structural rearrangement did not explain the heat-induced modifications. Emulsions E3 had a Fat Droplet interfacial layer composed of caseins whereas the WPM were only located in the continuous phase. These results demonstrate that the WPM do not contribute to emulsion heat-stability but they do not induce heat instability as long as they are not situated at the Fat Droplet interface. Knowing the total interfacial area, the amount of caseins to obtain heat stable emulsions containing WPM can be evaluated because the caseins dominate WPM adsorption at the Fat Droplet surface. This knowledge will allow controlling the stability of dairy emulsions in a wider whey protein concentration range than when using native whey proteins.
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Increasing the heat stability of whey protein-rich emulsions by combining the functional role of WPM and caseins
Food Hydrocolloids, 2018Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Pascaline Hamon, Florence Rousseau, Jonathan Thevenot, Thomas CroguennecAbstract:Abstract The heat stability of whey protein emulsions remains a real challenge due to the rapid denaturation/aggregation of native whey proteins on heating. The use of heat-stable Pickering-like whey protein microgels (WPM) makes it possible to develop heat-stable emulsions in a large range of whey protein concentrations. In this study, emulsion heat stability was evaluated with a special focus on the contribution of WPM adsorbed at the Fat Droplet surface and in the continuous phase of the emulsion. Dairy emulsions were prepared with 30% milk Fat and 70% suspension of WPM in the dispersed phase of milk. The protein interfacial load and the composition of the Fat Droplet surface were determined immediately after emulsion formation, and the heat stability of the emulsions at 120 °C was assessed visually and at microscopic scale. WPM are heat stable in the continuous phase of the emulsion, but the presence of WPM at the surface of the Fat Droplets is responsible for a rapid gelation of the emulsions. In the heated emulsions, the Fat Droplets seemed to be crosslinked by WPM. The presence of caseins instead of WPM at the Fat Droplet surface allowed the heat stability of the emulsion to recover at low and high whey protein concentrations. This study shows that it is possible to prepare heat-stable whey protein–rich emulsions by using whey proteins previously aggregated as heat-stable WPM and a sufficient amount of caseins in order to fully cover the Fat Droplet surface. These results will contribute to the development of heat-stable whey protein–rich emulsions.
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aggregated whey proteins and trace of caseins synergistically improve the heat stability of whey protein rich emulsions
Food Hydrocolloids, 2016Co-Authors: Marie Chevallier, Christelle Lopez, Alain Riaublanc, Pascaline Hamon, Florence Rousseau, Thomas CroguennecAbstract:Abstract Heat treatments are used to extend the shelf life of manufactured food emulsions, which in turn require excellent heat stability. Whey protein aggregation prior to homogenization is a means to modify emulsion heat stability but the underlying mechanism of heat stabilization has hardly been studied in an industrial context where whey protein ingredients contain caseins. Emulsions were prepared with 30% anhydrous milk Fat and 70% whey protein/casein solutions with protein concentrations ranging from 3 to 6%. The proteins were either unheated (WP/Cas samples) or heat-aggregated (A-WP/Cas samples). After homogenization, the Fat Droplet interface was characterized and emulsion stability was analyzed visually and at microscopic level. WP/Cas emulsions were heat stable at low protein concentrations but exhibited a gradual decrease in heat stability when the protein concentration increased (>3%). This instability was due to the co-gelation of the protein-coated Fat Droplets and the proteins in the dispersing phase. In contrast, A-WP/Cas emulsions were rapidly heat destabilized at low protein concentrations (
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Fat supramolecular structure in Fat-filled dairy powders: A tool to adjust spray-drying temperatures
Dairy Science & Technology, 2010Co-Authors: M.l. Vignolles, Cécile Le Floch-fouéré, Jean-jacques Ehrhardt, Romain Jeantet, Serge Mejean, Christelle Lopez, Pierre SchuckAbstract:Despite the increasing economic impact of Fat-filled dairy powders, their manufacture is still empirical. The aim of the study was to understand the mechanisms responsible for Fat supramolecular structure in such a dry matrix. For the purpose, emulsions were obtained under controlled manufacturing conditions. Then, they were dried under different inlet air temperatures, leading to different drying kinetics. Fat Droplet size was determined in both emulsions and powders. Free Fat and surface Fat were assessed to characterize Fat in the resulting powders. Confocal laser scanning microscopy was used to characterize Fat supramolecular structure in situ in the powder particles. Results showed that Fat supramolecular structure in Fat-filled dairy powders was connected with drying air temperatures, not necessarily with drying kinetics. Inlet air temperature and consequently temperature of the drying Droplet had the most significant influence. Such a study considering drying air temperatures and kinetics is essential in elucidating the mechanisms of free Fat formation and the presence of Fat at the surface of powder particles. Mechanisms underlying Fat supramolecular structure in Fat-filled dairy powders are proposed: They can be used as a tool to adjust spray-drying air temperatures and kinetics.
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Protein-lactose matrix effects on Fat encapsulation during the overall spray-drying process of dairy powders
Australian Journal of Dairy Technology, 2009Co-Authors: M.l. Vignolles, Jean-jacques Ehrhardt, Serge Mejean, Pierre Schuck, Christelle Lopez, Marie-noelle Madec, Romain JeantetAbstract:Fat encapsulation by a protein-lactose matrix has been investigated all along the spray-drying process of Fat-filled dairy powders. The matrix was made of micellar casein, whey proteins or heat-denatured whey proteins, alone or with amorphous lactose. Results showed that the presence of amorphous lactose was essential to emulsify and encapsulate Fat: it could act as a hydrophilic protective agent, especially with heat-denatured whey proteins. With amorphous lactose, micellar casein and whey proteins were better emulsifiers than heat-denatured whey proteins with regard to the formation of Fat Droplet with smaller size however, only native whey proteins proved to be better encapsulating agents with regard to free Fat and surface Fat. Hence, whey proteins, when weakly heat-denatured, and in the presence of amorphous lactose, could be used as effective ingredients to encapsulate Fat in dairy powders.