25 results on '"Marie-Hélène Famelart"'
Search Results
2. Mixed dairy and plant-based yogurt alternatives: Improving their physical and sensorial properties through formulation and lactic acid bacteria cocultures
- Author
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Fanny Canon, Marie-Bernadette Maillard, Marie-Hélène Famelart, Anne Thierry, and Valérie Gagnaire
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Applied Microbiology and Biotechnology ,Food Science ,Biotechnology - Abstract
Food transition requires incorporating more plant-based ingredients in our diet, thus leading to the development of new plant-based products, such as yogurt alternatives (YAs). This study aimed at evaluating the impact of lactic acid bacteria (LAB) cocultures and formulation on the physico-chemical and sensory properties of YAs. YAs were made by emulsifying anhydrous milk fat (AMF) or coconut oil in milk and lupin protein suspensions. The starters used, in mono- and cocultures, were the strains
- Published
- 2022
3. Protein aggregates modulate the texture of emulsified and acidified acid milk gels
- Author
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Perrine Gélébart, Marie-Hélène Famelart, Valérie Beaumal, Catherine Garnier, Alain Riaublanc, Camille Jonchère, Marc Anton, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, used to modulate their texture. The di ff erence of functionality between preformed and in situ produced mixed and microgel aggregates should be further investigated. Acknowledgements This work was supported by the Regional councils of Brittany (grant no. 13008651) and Pays de la Loire (grant no. 2014-07081) through fi nancial support and the INRA for its scienti fi c coordination (J. Leonil, STLO) through the interregional project PROFIL, managed by the Bba Industrial Association., and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
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animal structures ,Fat content ,General Chemical Engineering ,agrégat protéique ,Protein aggregation ,casein ,01 natural sciences ,Homogenization (chemistry) ,protéine de lait ,0404 agricultural biotechnology ,Adsorption ,Rheology ,Casein ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,0103 physical sciences ,rhéologie ,gel acide ,emulsion ,lactoserum ,caséine ,010304 chemical physics ,protéine de lactosérum ,Chemistry ,rhéologie interfaciale ,whey protein ,04 agricultural and veterinary sciences ,General Chemistry ,Microstructure ,040401 food science ,Chemical engineering ,agrégat ,texture ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,Protein network ,Food Science - Abstract
Acid milk gels with fat (3.5 or 10%) or without fat containing 0.2–1% of whey proteins (WP) or 0.2–1.5% of protein aggregates (fractal aggregates, microgels and mixed casein/WP aggregates with an 80/20 ratio) were investigated. The fat-containing systems were homogenized and the systems were preheated (90 °C, 11 min) and acidified to a pH of 4.6 by adding glucono-delta-lactone. The protein composition of the fat droplet interface was characterized by SDS-PAGE and the textural and rheological properties, microstructure, and whey separation of acid networks were determined. WP and fractal aggregates showed the best ability to improve the textural properties and microstructure of all acid milk gels and reduce whey separation. Increasing the concentrations in microgels and mixed aggregates did not lead to an increase in gel firmness or generate a strong impact on the protein network, but a high concentration in mixed aggregates could reduce whey separation. The fat droplet interface was made almost exclusively of caseins, even if the fractal aggregates could also be adsorbed when the interfacial surface was increased either through fat content or through an increase in homogenization pressure. Adding proteins changes the textural properties of the acid gels in all the systems, mainly due to their role in the continuous phase.
- Published
- 2019
4. Atomic force microscopy to assess the mechanical properties of individual casein micelles
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Julien Bauland, Antoine Bouchoux, Thomas Croguennec, Marie-Hélène Famelart, Fanny Guyomarc'h, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Chr. Hansen A/S, Toulouse Biotechnology Institute (TBI), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
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General Chemical Engineering ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Young modulus ,Micellar calcium phosphate ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,General Chemistry ,AFM ,Casein micelle ,Contact angle ,health care economics and organizations ,Food Science - Abstract
International audience; Casein micelles (CMs) are ~100 nm natural colloids found in milk resulting from the complex and unresolved association of casein monomers, phosphorus, and calcium; the latter being either directly bound to the phosphoserine residues of caseins or present as nanoclusters of insoluble micellar calcium phosphate (MCP). Dairy products such as cheese or yogurt are colloidal gels formed by CMs destabilization, for which texture and ability to be processed are essentially determined by rheological properties. Those properties depend on the physicochemical conditions used during gel formation (e.g., pH, temperature, ionic content). However, questions remain about the origin of this dependence at the microscopic scale. In particular, we still do not have a clear picture of the specific contributions of the rigidity of the elementary bricks (CMs) in comparison with the interparticles interactions or their spatial distribution. In this work, Atomic Force Microscopy (AFM) is used to evaluate changes in the nanomechanical properties of single CMs following physico-chemical modifications that are known to affect the MCP content and the rheology of the enzymatic milk gel (i.e. decrease of pH and CaCl 2 addition). AFM is used as a direct indenter that assesses the CMs' elastic deformation and gives an estimate of their Young modulus. We show that for a ±18-24% w/w depletion or enrichment in MCP content, the Young modulus of CMs significantly decreases or increases, respectively. This correlation suggests that variations in the modulus of individual CMs could explain the changes in the macroscopic properties of the enzymatic milk gel upon variations of physico-chemical conditions.
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- 2022
5. Rheological characterization of β-lactoglobulin/lactoferrin complex coacervates
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Rima Soussi Hachfi, Marie-Hélène Famelart, Florence Rousseau, Pascaline Hamon, and Saïd Bouhallab
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Food Science - Published
- 2022
6. Powder properties and influencing factors
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Yrjö H. Roos, Zahra Afrassiabian, Khashayar Saleh, Marie-Hélène Famelart, Alexia Audebert, Muhammad Gulzar, Thomas Croguennec, Jennifer Burgain, Tristan Fournaise, Claire Gaiani, Joël Scher, Jérémy Petit, Evandro Martins, Ramila Cristiane Rodrigues, Pierre Schuck, Ítalo Tuler Perrone, Solimar Gonçalves Machado, and Antônio Fernandes de Carvalho
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Whey protein ,Caking ,Water activity ,Chemical engineering ,Chemistry ,law ,Spray drying ,Vapour pressure of water ,Particle ,Water content ,Filtration ,law.invention - Abstract
3.1 Water activity is related to water vapor pressure in a material, and it is a useful parameter relating to glass transition, water content and water plasticization. The glass transitions of dairy solids, particularly that of lactose, determine the dehydration characteristics and successful spray-drying conditions of dairy liquids. Water and glass transition relationships assist in the selection of spray-drying parameters as well as required storage conditions. A critical water activity and glass transition-related strength of dairy solids are useful in the formulation of dairy food with desired physicochemical stability in processing and storage. 3.2 Caking is a common root of many problems encountered when handling powders and can lead to unwanted shutdowns, client claims and product recycling/rejection due to the clogging of conveying lines, feeding devices and storage silos. Caking can be defined as a formation of material bonds at the points of contact between particles that leads to undesired and uncontrolled agglomeration of powders. It is a very complex process bringing into play a multitude of interactions and mechanisms resulting from variations in environmental conditions, in particular those of temperature and relative humidity. The objective of this chapter is to describe the fundamental mechanisms of powder caking and especially those involved in the caking of dairy powders. 3.3 This chapter presents the structural changes at protein/aggregate scale and the changes of functionalities (water-holding capacity, viscosity, foaming, emulsifying and gelling properties) resulting from the pre-texturizing of whey proteins by heating in dry state. The first part of this chapter describes the main chemical/structural modifications occurring during protein dry-heating (limited protein unfolding, Maillard reaction, dehydration reactions) and the specificities of the aggregation reactions that are controlled by molecular mobility (or a w ) and the presence of heat-sensitive compounds (type and amount of sugars). Then, the second part of the chapter describes the functionalities of the pre-texturized whey protein by dry-heating. The change of functionalities can be huge, as shown for the modification of viscosity of protein solutions after whey protein dry-heating at alkaline pH (protein particles are able to trap up to 30g of water per g of protein). The strength of the whey protein gels is increased two-fold by the dry-heating treatment, favoring the formation of soluble aggregates. The change in the foaming properties after whey protein dry-heating is much more limited. 3.4 The perceived quality of dairy powders obtained by spray-drying depends on their functional properties, i.e., their ability to flow easily and rehydrate quickly without lump formation. These requirements can be achieved provided that the physicochemical properties of the powders are mastered by an adequate choice of formulation and spray-drying conditions. On one hand, this chapter presents the impact of the spray-drying conditions on the physicochemical characteristics of the resulting dairy powders and highlights the tremendous role of the evaporation rate in the particle structure and surface composition. On the other hand, the influence of the main powder physical properties (particle size, shape, microstructure and surface mechanical properties) on flowing properties and rehydration capacity is discussed through examples of dairy powders produced by spray drying. In order to complete this discussion of the link between spray-drying conditions, physicochemical properties and functionalities, the main analytical methods used to assess spray-dried dairy powder characteristics are briefly reviewed throughout the chapter. 3.5 Initial milk contamination may occur due to intramammary infections, microorganisms on the external udder surface, poorly sanitized handler hands and milking equipment. During the refrigeration, storage and transport stages, lapses in hygienic-sanitary conditions can lead to milk contamination from pathogenic and spoilage microorganisms. Once raw milk reaches the processing plant for dehydration, it undergoes processes including cooling, heat treatments, evaporative procedures and membrane filtration in order to inhibit microbial growth and destroy microorganisms. Following thermal treatments and membrane filtration, caution should be taken to ensure the hygienic-sanitary conditions of equipment and utensils to avoid product recontamination. All the stages of dried dairy products (from milking to packaging) should be monitored to guarantee the quality and microbiological safety of these foods.
- Published
- 2020
7. Dry heating of whey proteins
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Elise Schong, Marie-Hélène Famelart, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, This work was supported by the Regional councils of Brittany (grant No. 13008651) and Pays de la Loire (grant no. 2014-07081) for the financial support and by INRA for scientific coordination (J. Leonil) through the interregional project PROFIL, managed by BBA industrial association., and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
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Glycation End Products, Advanced ,Thermotolerance ,séchage ,Protein Denaturation ,Whey protein ,animal structures ,technologie laitière ,agrégat protéique ,procédé de séchage ,Heating ,Protein Aggregates ,protéine de lait ,fluids and secretions ,0404 agricultural biotechnology ,Liquid state ,protéine laitière ,Glycation ,Whey ,Dry heating ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Denaturation (biochemistry) ,Food science ,Desiccation ,comportement au séchage ,functionality ,2. Zero hunger ,Chromatography ,protéine de lactosérum ,Chemistry ,digestive, oral, and skin physiology ,Temperature ,food and beverages ,whey protein ,04 agricultural and veterinary sciences ,fonctionnalité ,040401 food science ,agrégation ,Maillard Reaction ,Whey Proteins ,Solubility ,dénaturation ,Proteolysis ,glycation ,Gels ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,Food Science - Abstract
Whey protein products are of widespread use as food ingredients because of their high nutritional, biological and functional properties. Whey proteins are important structural components in many foods as used in their native form, for example for their heat-induced gelation abilities. Furthermore, they also offer reliable functionalities when modified by heating processes as denatured or aggregated proteins. Heat treatment of whey proteins in a liquid state has received much attention in recent years. While dry heating of whey proteins, say heating whey proteins in the dry state, is frequently cited in the literature as a potential and efficient means to improve the functional properties of proteins, it has received very little attention. We report first on the dry heating of whey products as applied to promote glycation of whey proteins with a low denaturation, and second, to promote their denaturation and aggregation and on their consequences on the functional properties of whey proteins.
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- 2017
8. The Role of Proteins in the Development of Food Structure
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Saïd Bouhallab, Valérie Gagnaire, Marie-Hélène Famelart, Valérie Lechevalier, Thomas Croguennec, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
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Egg protein ,Computational biology ,Biology ,human health ,produit laitier ,structure de l'aliment ,propriété fonctionnelle ,assemblage protéique ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,besoin en protéines ,santé ,Food structure ,Flexibility (engineering) ,propriété physico-chimique ,assemblage de protéine ,business.industry ,santé humaine ,propriété physique des protéines ,acide aminé ,nutrition ,dairy product ,functional property ,protéine ,Food products ,oeuf ,New product development ,egg ,protein ,business ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,amino acid - Abstract
Understanding the behavior and structure of food products requires knowledge of the spatial arrangement of the various components and their interactions. Among these components, proteins, beyond their roles in nutrition and health, exhibit specific functional properties inherited from both their molecular flexibility and the plasticity of their diversified assemblies. These structural and functional properties make food proteins versatile and useful ingredients in a wide range of product development. This chapter reviews the role of proteins in the development of food structure with a focus on milk and egg proteins. We first describe the main proteins, their physicochemical characteristics, and the diversity of assembled structures obtained during processing. Through specific examples, including proteins gels, yogurt, and various cheeses, we illustrate how the properties of proteins are explored in the manufacture of food.
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- 2019
9. Influence of casein on the formation of whey protein microparticles obtained by dry heating at an alkaline pH
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Elise Schong, Marie-Hélène Famelart, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Regional councils of Brittany (grant N13008651) and Pays de la Loire (grant n°2014-07081) for financial support and INRA for scientific coordination (J. Leonil) through the interregional project PROFIL, managed by the BBA industrial association, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
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séchage ,Whey protein ,Hot Temperature ,030309 nutrition & dietetics ,Food Handling ,whey paste ,procédé de séchage ,casein ,produit laitier ,Whey protein isolate ,03 medical and health sciences ,0404 agricultural biotechnology ,protéine de lait ,microparticule ,Dry heating ,Casein ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Browning ,Microparticle ,Particle Size ,Porosity ,0303 health sciences ,lactosérum ,caséine ,biology ,Chemistry ,Caseins ,04 agricultural and veterinary sciences ,Hydrogen-Ion Concentration ,protéine de lactoserum ,040401 food science ,agrégation ,microparticle ,Whey Proteins ,dairy product ,Yield (chemistry) ,biology.protein ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,Food Science ,Nuclear chemistry - Abstract
Dry heating (DH) at 100 °C for 36 h of a whey protein isolate powder conditioned at pH 9.5 leads to the formation of stable, large and porous whey protein microparticles (PMs), resulting from the crosslinking of proteins inside the powder. These PMs could be used as high-viscosity food ingredients. Casein, present as a contaminant in whey protein powders, has been shown to become incorporated into the PMs. In this study, we investigated the effect of adding increasing amounts of sodium caseinate to whey protein powders on the formation of PMs during DH at 100 °C for 36 h. In addition, we studied PM formation during DH of a micellar casein-enriched milk protein powder (Casmic). The browning index of the dry-heated powders, and the size and water content of the microparticles were also characterized. We confirmed that sodium caseinate was incorporated into the PMs. The highest PM D[4,3] values (270 μm) were observed for powders with around 40% caseinate. Powders without added caseinate displayed D[4,3] values of 150 μm. The yield of conversion of proteins into PMs increased from 0.6 to 0.8 g/g with caseinate addition, whereas the amount of water entrapped in the PMs decreased from around 30 to 20 g/g. PMs were also formed by DH of the Casmic powder, but these particles were smaller, with sizes of around 80 μm. In conclusion, our study shows that the process of DH at pH 9.5 could be applied to all milk proteins to obtain PMs with functional properties that could be used in the food industry.
- Published
- 2018
10. A novel technique for determining glass–rubber transition in dairy powders
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Pierre Schuck, Donal J. O'Callaghan, Sean A. Hogan, and Marie-Hélène Famelart
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Materials science ,Transition temperature ,Analytical chemistry ,law.invention ,Differential scanning calorimetry ,Rheology ,Natural rubber ,Magazine ,law ,visual_art ,Spray drying ,visual_art.visual_art_medium ,Relaxation (physics) ,Glass transition ,Food Science - Abstract
A novel rheological technique is described, for determining the glass–rubber transition temperature ( T gr ) of spray dried dairy powders. The approach involves constant rate heating of powder under compression and measurement of changes in either gap distance (Method 1) or normal force (Method 2). Significant increases in the rate of change of these parameters was shown to correspond with T gr . The techniques were applied to skim milk, micellar casein and whey permeate powders and a range of fat-enriched micellar casein powders. T gr temperatures, so obtained, were compared with glass transition temperatures ( T g ) determined by Differential Scanning Calorimetry (DSC). Methods 1 and 2 gave predictions for non-fat dairy powders of T g endset ( T ge ) with SEP of 8.8 and 4.4 °C, respectively. These novel techniques provide an accurate means of determining glass transitions in dairy powders, including high protein and fat-containing powders, whose relaxation properties can be difficult to measure by DSC.
- Published
- 2010
11. Reducing salt level in food: Part 1. Factors affecting the manufacture of model cheese systems and their structure–texture relationships
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Juliane Floury, Florence Rousseau, Christelle Lopez, Marie-Hélène Famelart, Bénédicte Camier, Jean-Pierre Tissier, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
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MODEL CHEESE ,Chemistry ,Scanning electron microscope ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,TEXTURE PROFILE ANALYSIS ,Microstructure ,040401 food science ,040201 dairy & animal science ,0404 agricultural biotechnology ,Rheology ,[SDV.IDA.SMA]Life Sciences [q-bio]/Food engineering/domain_sdv.ida.sma ,Anhydrous ,Rennet ,Dry matter ,Food science ,Texture (crystalline) ,Globules of fat ,MICROSTRUCTURE ,STRUCTURE PROPERTIES ,Food Science - Abstract
A model lipoproteic matrix able to mimic hard-type cheese was produced with controlled structural and textural properties. Changes in the microstructural and rheological properties of these model cheeses made from different milk concentrate powder, anhydrous milk fat, salt contents and pH values at renneting were characterised. Rheological properties were measured by texture profile analysis, fat globule and protein aggregate size distributions by laser light scattering. Microstructural properties of the model matrices were studied by confocal laser scanning and scanning electron microscopy. Significant differences between the matrices were found for the structural, physico-chemical and rheological parameters measured. Cheeses with higher dry matter content were significantly harder and contained more insoluble proteins than cheeses with lower dry matter content. The salt concentration and the pH at renneting had significant influence on cheese hardness and adhesiveness of rheological parameters. The model lipoproteic matrix presented air bubbles and powder aggregates which could not be avoided during the manufacture of products. However, compared with classic cheese making with rennet or acid coagulation, the technology used here allows model cheeses to be produced rapidly with a good reproducibility of texture.
- Published
- 2009
12. L'affinage limité des fromages maigres produits par UF s'expliquerait-il par la présence d'une barrière de phosphate de calcium ?
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Jean-Pierre Tissier, J.A. Hannon, Marie-Hélène Famelart, and Sylvie Lortal
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business.product_category ,fromage UF ,Scanning electron microscope ,oligoélément ,Diffusion ,Ultrafiltration ,fromage ,affinage ,migration ,Biochemistry ,calcium phosphate ,0404 agricultural biotechnology ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Texture (crystalline) ,Food science ,lactate---fromage à pâte molle ,2. Zero hunger ,lactate ,calcium ,biology ,Chemistry ,UF-cheese ,phosphate de calcium ,0402 animal and dairy science ,Ripening ,04 agricultural and veterinary sciences ,Microstructure ,biology.organism_classification ,040401 food science ,040201 dairy & animal science ,Agricultural sciences ,Carton ,Penicillium camemberti ,ultrafiltration ,surface-mould cheese ,SURFACE-MOULD CHEESE ,CALCIUM PHOSPHATE ,MIGRATION ,LACTATE ,business ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,Sciences agricoles ,Food Science - Abstract
International audience; The ripening of industrial soft cheeses manufactured using a liquid pre-cheese produced from the ultrafiltration (UF) of milk was observed to be slow in comparison to that of cheese manufactured by a traditional process. Moreover, in the UF-cheeses investigated in this study, which were produced using Penicillium camemberti as the surface flora, several surface defects were observed: the texture was 'carton' like and the rind frequently detached from the cheese. To gain a fuller understanding of the development of these surface defects in UF-cheeses, the migration of different minerals and ions, and the study of the rind microstructure by scanning electron microscopy and X-ray mapping were performed. The results suggest that the slower diffusion of lactate, possibly due to the mineral layer at the surface of cheeses, acting as a barrier to its diffusion, may have caused an alteration in the metabolism and growth of the surface mould and may explain the surface defects of these UF-cheeses.; Les fromages à pâte molle industriels produits par ultrafiltration (UF) à partir d'un pré-fromage liquide présentent un affinage retardé par rapport à des fromages produits à l'aide d'un procédé traditionnel. De plus, des fromages UF modèles produits avec seulement Penicillium camemberti comme flore de surface montrent une texture de carton et la croûte se détache souvent du fromage. La caractérisation des migrations des minéraux et des ions et l'étude de la microstructure de la croûte de ces fromages modèles par microscopie électronique à balayage et micro-analyse X ont été réalisées afin de comprendre l'origine de ces défauts. La diffusion retardée du lactate, peut-être due à la présence d'une couche minérale à la surface des fromages, pourrait être à l'origine de changements de métabolisme et de la croissance de la moisissure et pourrait expliquer la moindre qualité des fromages.
- Published
- 2009
13. Heat treatment of cream affects the physicochemical properties of sweet buttermilk
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Christelle Lopez, Marie-Hélène Famelart, Jean-Yves Gassi, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Revues Inra, Import
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[SDV.SA]Life Sciences [q-bio]/Agricultural sciences ,food.ingredient ,Pellets ,Phospholipid ,Biochemistry ,produit laitier ,chemistry.chemical_compound ,0404 agricultural biotechnology ,food ,TRAITEMENT THERMIQUE ,PROPRIETE PHYSICOCHIMIQUE ,BABEURRE ,CREME ,PHOSPHOLIPIDE ,PROTEINE ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Skimmed milk ,Centrifugation ,Food science ,ComputingMilieux_MISCELLANEOUS ,Chromatography ,Chemistry ,0402 animal and dairy science ,food and beverages ,04 agricultural and veterinary sciences ,[SDV.IDA] Life Sciences [q-bio]/Food engineering ,Total dissolved solids ,040401 food science ,040201 dairy & animal science ,Agricultural sciences ,Laser light scattering ,[SDV.AEN] Life Sciences [q-bio]/Food and Nutrition ,dairy product ,Composition (visual arts) ,Particle size ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,Sciences agricoles ,Food Science - Abstract
The objective of this work was to investigate the effect of heat treatment of sweet creams on the physicochemical properties of sweet industrial buttermilks. Creams with three different heat treatments: low, medium and high, were churned and the corresponding buttermilks were characterised. Furthermore, buttermilks were renneted and centrifuged to obtain insoluble pellets and supernatants. The physicochemical properties such as the particle size measured by laser light scattering and composition of creams, buttermilks, pellets and supernatants were determined and compared. Buttermilk had a composition close to that of skim milk but it contained more phospholipids (PL): 958 (± 137) mg·kg−1, compared with 120 mg·kg−1 in milk. The heat treatment induced a significant decrease in soluble protein contents in creams, buttermilks and soluble fractions as well as an increase in the buttermilk PL/fat ratio, and an increase in supernatant protein and total solids. Buttermilk and supernatant particle sizes ranged from 0.03 to 200 μm, with a maximum at 130 nm, which may correspond to small milk fat globules, phospholipid vesicles or protein aggregates. Fat and PL in buttermilks were recovered in supernatants. The use of buttermilk enzymatic coagulation combined with centrifugation may constitute a means to fractionate milk PL.
- Published
- 2008
14. The Formation of Calcium Lactate Crystals is Responsible for Concentrated Acid Whey Thickening
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D. Naegele, Arnaud Mimouni, Pierre Schuck, Marie-Hélène Famelart, and Saïd Bouhallab
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Time Factors ,Food Handling ,chemistry.chemical_element ,Calcium ,law.invention ,chemistry.chemical_compound ,fluids and secretions ,Rheology ,law ,Genetics ,medicine ,Microscopy, Phase-Contrast ,Lactic Acid ,Food science ,Dehydration ,Crystallization ,Lactose ,digestive, oral, and skin physiology ,food and beverages ,Calcium Compounds ,Hydrogen-Ion Concentration ,Milk Proteins ,Phosphate ,medicine.disease ,Lactic acid ,Refractometry ,Whey Proteins ,Torque ,chemistry ,Chemical engineering ,Spray drying ,Lactates ,Food Technology ,Animal Science and Zoology ,Food Science - Abstract
The use of spray drying for dehydration of acid whey is generally limited by the appearance of uncontrolled thickening and solidifying of the whey mass during the lactose crystallization step. The origin of this physical change is still unknown and probably linked to complex interactions between physical properties and chemical composition of these products. To understand this phenomenon, we simulated the thickening of concentrated acid whey on a laboratory scale by measuring the flow resistance changes as a function of time and whey composition. The thickening process was characterized by an amplitude of torque and a lag time (induction time). Thickening of lactic acid whey concentrate occurred regardless of the presence of whey proteins or lactose crystals. Moreover, this work clearly demonstrated that the thickening process was due to the formation of filamentous structures corresponding to calcium lactate crystals and showed a large dependence on calcium and lactate contents, pH, and phosphate concentration.
- Published
- 2007
15. Comprehensive study of acid gelation of heated milk with model protein systems
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Stéphane Pezennec, Michel Piot, Marie-Hélène Famelart, Jérome Tomazewski, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
- Subjects
Whey protein ,Globular protein ,Sodium ,Ingénierie des aliments ,chemistry.chemical_element ,casein ,Applied Microbiology and Biotechnology ,Colloid ,protéine de lait ,0404 agricultural biotechnology ,gelation thermique ,Casein ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Food engineering ,Food and Nutrition ,gel acide ,rhéologie ,gélation ,Solubility ,Polyacrylamide gel electrophoresis ,chemistry.chemical_classification ,beta lactoglobuline ,caséine ,Chromatography ,biology ,Chemistry ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,traitement thermique ,ovalbumine ,traitement thermique de l'aliment ,040401 food science ,040201 dairy & animal science ,Ovalbumin ,Alimentation et Nutrition ,biology.protein ,propriété physicochimique du lait ,rheology ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,Food Science - Abstract
The effect of heat treatment of milk on the formation of acid gels was investigated using model protein systems. Protein systems contained micellar casein alone (35 g kg −1 ) (systR) or in the combination with either β -lactoglobulin ( β LG) (4 g kg −1 ; systB) or egg ovalbumin (4 g kg −1 ; systO). Proteins in a milk ultrafiltrate (UF) were heat-treated at 90°C for 24 min. The same heat-treated systems without casein were also prepared: the UF alone (systUFR), with β LG (4 g kg −1 ; systUFB) and with ovalbumin (4 g kg −1 ; systUFO). Proteins in pellet and supernatant fractions were analysed using reverse-phase high-pressure liquid chromatography and sodium dodecyl sulphate polyacrylamide gel electrophoresis. The solubility of globular proteins in heated systUFB and heated systUFO was determined at pH 1.6–6.5 by absorbance measurements. Rheological changes during gelation with a starter at 42°C were determined and microstructures of gels by scanning electron microscopy. High quantities of κ -casein and β LG in the form of complexes (disrupted by 2-mercaptoethanol) were found in supernatant of heated systB and not in that of systO. The gelation pH was related to the solubility of the globular proteins, and the gelation pattern for systB and systO resembled that of heated milk and the systR pattern resembled that of unheated milk. The gels of systR were coarse and consisted of large particles. Particles in gels from systB and systO were smaller and less clustered. Although the two globular proteins behave differently during heating, they both confer to the casein micelles their solubility properties as a function of pH. A model is presented where both soluble and colloidal complexes including the globular protein interact at pH 5.5 and initiate the acid gelation.
- Published
- 2004
16. Article
- Author
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Anne Laligant, Denis Paquet, Gérard Brulé, and Marie-Hélène Famelart
- Subjects
0404 agricultural biotechnology ,Lactic bacteria ,Stereochemistry ,Chemistry ,0402 animal and dairy science ,Fermentation ,04 agricultural and veterinary sciences ,Intrinsic fluorescence ,040401 food science ,040201 dairy & animal science ,Lactic acid fermentation ,Food Science ,Nuclear chemistry - Abstract
Le comportement du lait ecreme traite thermiquement au cours de l'acidification par des bacteries lactiques est etudie a 30 et 42 °C. Les modifications rheologiques par oscillations dynamiques et le temps de relaxation T2 en RMN du proton sont etudies en fonction du temps et du pH. La fluorescence frontale intrinseque etudiee conjointement avec l'analyse en composantes principales a ete suivie au cours de la fermentation. La gelification du lait apparait a un temps plus court et un pH plus eleve a 42 °C (5,53 ± 0,01) qu'a 30 °C (5,24 ± 0,13). Le pic de maximum de tan δ etait plus marque a 42 qu'a 30 °C, mais le G t a pH 4,6 avait la meme valeur aux deux temperatures. Les changements de T2 au cours de l'acidification etaient peu differents aux deux temperatures etudiees, mais les courbes dT2/dpH montrent quelques differences entre 42 et 30 °C. Les changements de T2 sont dus a des changements de structure de la particule provoques par la fermentation et sont correles a la solubilisation du calcium. La fluorescence frontale detecte un premier decalage des spectres vers des longueurs d'onde plus petites puis un decalage vers des longueurs d'onde plus grandes. Le point associe a l'inversion de l'environnement des tryptophanes des chaines proteiques correspond au point de gel. Ces resultats et les differences avec des gels acides obtenus par l'addition de GDL sont discutes en terme de limitation des transferts d'acides et de protons de la phase aqueuse vers la phase colloidale et de l'heterogeneite du gel qui en decoule.
- Published
- 2003
17. Ecofriendly Fast Synthesis of Hydrophilic Poly(ethyleneglycol)-Ionic Liquid Matrices for Liquid-Phase Organic Synthesis
- Author
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Jean Pierre Bazureau, Marie-Hélène Famelart, Joan Fraga-Dubreuil, Chimie et Photonique Moléculaires (CPM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut de Chimie, Synthèse et Electrosynthèse Organiques 3, UMR 6510, Campus de Beaulieu, Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)
- Subjects
Poly ethyleneglycol ,Inorganic chemistry ,Ingénierie des aliments ,Liquid phase ,solvant ,010402 general chemistry ,Metathesis ,Mass spectrometry ,01 natural sciences ,Ion ,spectrometry ,éthylèneglycol ,chemistry.chemical_compound ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Polymer chemistry ,Food and Nutrition ,Food engineering ,Physical and Theoretical Chemistry ,éthylène glycol ,composé volatil organique ,chromatographie ,010405 organic chemistry ,Imidazolium chloride ,Organic Chemistry ,0104 chemical sciences ,chemistry ,Alimentation et Nutrition ,Ionic liquid ,chromatography ,spectrométrie ,Organic synthesis ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition - Abstract
New, hydrophilic poly(ethyleneglycol)-ionic liquids have beensynthesized and investigated, based on 1,3-disubstituted imidazolium cations and fluorinated anions (BF4 -, PF6 -,(CF3SO2)2N-, or NTf2 -). A series of typical solvent-free reactions have been safely realized using a focused microwave reactor for the preparation of imidazolium chloride precursors in yields ranging from 73 to 94% followed by quantitative anion metathesis exchanges. The poly(ethyleneglycol)-ionic liquid matrices were also characterized by NMR (1H, 13C), mass spectrometry (MS), and their dynamic viscosity was determined at 25 °C. These poly(ethyleneglycol)-ionic liquid phases (PEGILPs) as task-specific ionic liquids are promising tools for synthetic applications in liquid-phase combinatorial chemistry.
- Published
- 2002
18. Characterisation of whey drainage kinetics during soft cheese manufacture in relation with the physicochemical and technological factors, pH at renneting, casein concentration and ionic strength of milk
- Author
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Daniel J. Jacob, Jean-Louis Maubois, Henri Goudédranche, Célina Daviau, Marie-Hélène Famelart, Alice Pierre, and Maurice Garnier
- Subjects
Ultrafiltration ,soft cheese manufacture---lactosérum ,chemistry.chemical_compound ,fluids and secretions ,0404 agricultural biotechnology ,whey drainage ,Casein ,milk composition ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,composition du lait ,Cheesemaking ,Food science ,Drainage ,Lactose ,emprésurage ,2. Zero hunger ,cinétique ,Chromatography ,pH ,0402 animal and dairy science ,food and beverages ,04 agricultural and veterinary sciences ,fromage pâte molle ,040401 food science ,040201 dairy & animal science ,Dilution ,chemistry ,kinetics ,Ionic strength ,Rennet ,égouttage ,renneting ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,Food Science - Abstract
International audience; The kinetics of whey drainage of Camembert soft cheese was studied using an instrumented drainage device to record the pH and the weight of the whey with a variation coefficient amounting to 1.8% during the first 100 min and 0.34% at the end of drainage. Drainage data were fit with a two step equation to obtain a descriptive model of the drainage kinetics. The effect of the pH at renneting, the casein concentration and the ionic strength on the drainage kinetics was investigated with a 2 level experimental design. Milk was modified by a combination of ultrafiltration and dilution with a lactose solution. The pH at renneting had a negative effect on the amount of whey expelled in the early drainage (up to 100 min) and a positive one after 400 min. The effect of the casein concentration was negative on the amount of whey expelled and on the rate of drainage. The ionic strength had a slight positive effect on drainage. An equation was obtained allowing the prevision of whey drainage kinetics according to the milk composition. Calculated values fit experimental data with a correlation coefficient of $r = 0.994$.; Caractérisation des cinétiques d'égouttage au cours de la fabrication d'un fromage type pâte molle en relation avec les facteurs physico-chimiques et technologiques : effet du pH d'emprésurage, de la teneur en caséine et de la force ionique des laits. L'égouttage du fromage à pâte molle de type Camembert a été étudié à l'aide d'un prototype d'égouttage instrumenté qui permettait d'enregistrer le poids de sérum et son pH. Le coefficient de variation était de 1,8 % pendant les 100 premières minutes et de 0,34 % à la fin de l'égouttage. Les cinétiques d'égouttage obtenues ont été ajustées à l'aide d'un modèle mathématique descriptif à deux phases. L'effet sur l'égouttage du pH à l'emprésurage et de modifications de la composition du lait, telle la concentration en caséine et la force ionique, ont été testés à l'aide d'un plan d'expérience à deux niveaux. La composition des laits était modifiée en combinant une concentration par ultrafiltration et une dilution par une solution de lactose. L'effet du pH sur le poids de sérum expulsé était négatif au début de l'égouttage puis devenait positif. L'effet de la concentration en caséine était négatif sur la quantité de sérum obtenue et sur la vitesse d'égouttage. La force ionique avait un léger effet positif sur l'égouttage. Une équation a été obtenue permettant de prévoir la cinétique d'égouttage en fonction de la valeur des trois facteurs étudiés. Les valeurs calculées s'ajustaient aux valeurs expérimentales avec un coefficient de corrélation $r=0,994$.
- Published
- 2000
19. High pressure-induced gel formation of milk and whey concentrates
- Author
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L. Chapron, Michel Piot, Marie-Hélène Famelart, C. Durier, G. Brule, UR 0121 Laboratoire de recherche de Technologie Laitière, Institut National de la Recherche Agronomique (INRA), Unité mixte de recherche de technologie des ovoproduits, Ecole Nationale Supérieure Agronomique de Rennes-Institut National de la Recherche Agronomique (INRA), and Unité de recherche Biométrie (UB)
- Subjects
Chromatography ,Microfiltration ,Sodium ,0402 animal and dairy science ,Ultrafiltration ,food and beverages ,A protein ,chemistry.chemical_element ,04 agricultural and veterinary sciences ,040401 food science ,040201 dairy & animal science ,CONCENTRE DE PROTEINE ,Colloid ,chemistry.chemical_compound ,fluids and secretions ,0404 agricultural biotechnology ,chemistry ,High pressure ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Sodium citrate ,Condensed milk ,Food Science - Abstract
Gels from milk concentrates [milk and caseinate powder, ultrafiltration (UF) and microfiltration (MF)] and whey concentrates (UF) were obtained with high pressure (200 and 400 MPa, 10 and 30 min). The effects of protein concentration (66–114gkg −1 for milk and 97–127g kg −1 for whey), NaCl addition (0–8 g kg −1 ), sodium citrate addition (0–4 g kg −1 ) and pH (5.2–6.6 for milk and 7–9 for whey) were studied with a Box-Behnken design. Milk supplemented with casemate powder did not lead to gel formation by pressure. For UF or MF milk concentrates, a pH decrease towards 5.9 and a protein content increase led to firmer pressure-set gels. Gels of whey concentrates were obtained only at pH 9. A pressure increase from 200 to 400 MPa led to firmer gels, while a protein content increase did not.
- Published
- 1998
20. Acid and rennet gels exhibit strong differences in the kinetics of milk protein digestion and amino acid bioavailability
- Author
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Béatrice Laroche, Marie-Hélène Famelart, Yann Le Gouar, Didier Dupont, Caroline Buffière, Steven Le Feunteun, Florence Barbe, Olivia Ménard, Didier Rémond, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Unité de Nutrition Humaine (UNH), Institut National de la Recherche Agronomique (INRA)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Clermont Université, Unité de recherche Mathématiques et Informatique Appliquées (MIA), Institut National de la Recherche Agronomique (INRA), Génie et Microbiologie des Procédés Alimentaires (GMPA), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Food and Agriculture COST (European Cooperation in Science and Technology) Action FA1005 ‘Improving health properties of food by sharing our knowledge on the digestive process (INFOGEST), INRA, CNRS, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and AgroParisTech-Institut National de la Recherche Agronomique (INRA)
- Subjects
modèle animal ,Swine ,micelle de caséine ,Absorption (skin) ,digestion ,beta-lactoglobuline ,Analytical Chemistry ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Ingestion ,Animals ,gel acide ,Food science ,Amino Acids ,Intestinal Mucosa ,bioaccessibilité ,2. Zero hunger ,chemistry.chemical_classification ,Chromatography ,Chemistry ,digestive, oral, and skin physiology ,General Medicine ,Milk Proteins ,lait ,Animal Feed ,Amino acid ,Bioavailability ,Intestines ,acide aminé ,Kinetics ,protéine ,Swine, Miniature ,Rennet ,Composition (visual arts) ,Animal Nutritional Physiological Phenomena ,leucine ,Leucine ,Digestion ,Rheology ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,Chymosin ,Gels ,Food Science - Abstract
This study aimed at determining the kinetics of milk protein digestion and amino acid absorption after ingestion by six multi-canulated mini-pigs of two gelled dairy matrices having the same composition, similar rheological and structural properties, but differing by their mode of coagulation (acidification/renneting). Duodenal, mid-jejunal effluents and plasma samples were collected at different times during 7 h after meal ingestion. Ingestion of the acid gel induced a peak of caseins and β-lactoglobulin in duodenal effluents after 20 min of digestion and a peak of amino acids in the plasma after 60 min. The rennet gel induced lower levels of both proteins in the duodenum (with no defined peak) as well as much lower levels of amino acids in the plasma than the acid gel. Plasma ghrelin concentrations suggested a potentially more satiating effect of the rennet gel compared to the acid gel. This study clearly evidences that the gelation process can significantly impact on the nutritive value of dairy products.
- Published
- 2013
21. Iron-supplemented caseins: preparation, physicochemical characterization and stability
- Author
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Marie-Hélène Famelart, Frédéric Gaucheron, Yvon Le Graët, UR 0121 Laboratoire de recherche de Technologie Laitière, Institut National de la Recherche Agronomique (INRA), and ProdInra, Migration
- Subjects
[SDV.SA]Life Sciences [q-bio]/Agricultural sciences ,chemistry.chemical_classification ,[SDV.SA] Life Sciences [q-bio]/Agricultural sciences ,0303 health sciences ,Chromatography ,030309 nutrition & dietetics ,Chemistry ,Sodium ,Salt (chemistry) ,chemistry.chemical_element ,04 agricultural and veterinary sciences ,General Medicine ,040401 food science ,High-performance liquid chromatography ,Ferrous ,Absorbance ,03 medical and health sciences ,Fluorescence intensity ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Casein ,Animal Science and Zoology ,ComputingMilieux_MISCELLANEOUS ,Food Science ,Trisodium citrate - Abstract
SummaryPreparation, physicochemical characterization and stability of iron-supplemented caseins were studied. When ferrous iron (final concentrations of 0·25, 0·5, 1·0 and 1·5 mM) was added to sodium caseinate (final casein concentration 25 g/l), iron binding to caseins was complete. In parallel, an increase in absorbance at 280 nm, a decrease in fluorescence intensity, modifications of reversed-phase HPLC profile, a decrease in pH and an increase in free sodium concentration were observed. Moreover, no release of iron from iron-casein complexes was found between pH 6·5 and 3·7 or after heat treatments or in the presence of inorganic phosphate. Only EDTA disodium salt and trisodium citrate had significant effects on the release of iron bound to caseins.
- Published
- 1996
22. pH-Induced physicochemical modifications of native phosphocaseinate suspensions: Influence of aqueous phase
- Author
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Y. Le Graet, Frédéric Gaucheron, Marie-Hélène Famelart, F Lepesant, Pierre Schuck, and Revues Inra, Import
- Subjects
Milk protein ,Chemistry ,Ph induced ,0402 animal and dairy science ,Environmental factor ,Aqueous two-phase system ,04 agricultural and veterinary sciences ,[SDV.IDA] Life Sciences [q-bio]/Food engineering ,medicine.disease_cause ,040401 food science ,040201 dairy & animal science ,Molecular biology ,[SDV.AEN] Life Sciences [q-bio]/Food and Nutrition ,0404 agricultural biotechnology ,Biochemistry ,Solubilization ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,medicine ,[SDV.AEN]Life Sciences [q-bio]/Food and Nutrition ,ComputingMilieux_MISCELLANEOUS ,Food Science - Abstract
L'effet du pH sur les evolutions physicochimiques de suspensions de micelles de caseine, ainsi que sur les temps de coagulation presure, a ete etudie sur une poudre de phosphocaseinate natif reconstituee dans de l'eau, une solution 0,1 mol L -1 en NaCI et un ultrafiltrat de lait. L'augmentation de force ionique entre l'eau et NaCl provoque une augmentation des teneurs en calcium et en phosphore diffusibles, une plus grande voluminosite des micelles, et une augmentation de la solubilisation des caseines et des mineraux intervenant lors de l'acidification. La solubilisation du phosphocaseinate natif dans l'ultrafiltrat conduit a un comportement proche du lait. L'acidification peut etre divisee en cinq phases successives. Les relations entre les evolutions physicochimiques sont discutees, ainsi que la diminution des temps de coagulation presure avec la baisse du pH et de la force ionique.
- Published
- 1996
23. Role of the heat-induced whey protein/kappa-casein complexes in the formation of acid milk gels: a kinetic study using rheology and confocal microscopy
- Author
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Marie-Hélène Famelart, Véronique Le Tilly, Marie-Noelle Madec, Marlène Jemin, Fanny Guyomarc'H, Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Laboratoire d'Ingénierie des Matériaux de Bretagne, Université de Brest (UBO), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
- Subjects
Whey protein ,food.ingredient ,microscopie ,Hot Temperature ,HEAT-INDUCED COMPLEXES ,Micelle ,Colloid ,chemistry.chemical_compound ,0404 agricultural biotechnology ,food ,milk protein ,protéine du lait ,Phase (matter) ,Casein ,Skimmed milk ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Animals ,HEAT TREATMENT ,rhéologie ,Fluorescein isothiocyanate ,Micelles ,Chromatography ,Microscopy, Confocal ,0402 animal and dairy science ,Aqueous two-phase system ,food and beverages ,Caseins ,ACID MILK GEL ,04 agricultural and veterinary sciences ,General Chemistry ,Hydrogen-Ion Concentration ,Milk Proteins ,040401 food science ,040201 dairy & animal science ,lait ,CONFOCAL SCANNING LASER ,MICROSCROPY ,Milk ,Whey Proteins ,chemistry ,protéine ,microscopy ,General Agricultural and Biological Sciences ,protein ,Rheology ,Gels - Abstract
The effect of heat treatment of milk on the formation of acid gel was examined using confocal scanning laser microscopy and low-amplitude dynamic oscillation throughout acidification. Milk samples were reconstituted by mixing colloidal phase from unheated or preheated skim milk, labeled with rhodamine B isothiocyanate, with the aqueous phase from unheated or preheated milk, labeled with fluorescein isothiocyanate. Gels were made by acidification with glucono-delta-lactone. The presence of material from preheated milk, that is, either the colloidal or the aqueous phase or both, led to an increase in the gelation pH and in the final elastic modulus and to a more branched network with larger pores. During acidification, the heat-induced serum complexes and the casein micelles did not appear to form separated gels with time or in space. Moreover, the colocalization in the final network of serum heat-induced complexes and casein micelles is particularly well observed in the presence of an aqueous phase obtained from preheated milk. Finally, because the rheological and microstructural properties of acid gels containing either micelle-bound or serum heat-induced complexes were similar, it was suggested that the serum heat-induced complexes interacted with the casein micelles early in the course of acidification and that formation of the network did not differ significantly whether the heat-induced complexes were initially found in the aqueous phase of milk or bound to casein micelles.
- Published
- 2009
24. Heat induced gelation of acid milk: balance between weak and covalent bonds
- Author
-
Marie-Hélène Famelart and Olivier Surel
- Subjects
Heat induced ,Hot Temperature ,Chemical Phenomena ,Static Electricity ,chemistry.chemical_compound ,Organic chemistry ,Animals ,Urea ,Texture (crystalline) ,Disulfides ,Micelles ,Mercaptoethanol ,Chemistry ,Chemistry, Physical ,food and beverages ,Sodium Dodecyl Sulfate ,Hydrogen Bonding ,General Medicine ,Hydrogen-Ion Concentration ,Milk Proteins ,Balance (accounting) ,Milk ,Chemical bond ,Chemical engineering ,Covalent bond ,Ethylmaleimide ,Animal Science and Zoology ,Gels ,Food Science - Abstract
Gelation of acidified milk at pH[ges ]5, after heat treatments is a well known phenomenon, due to the precipitation of whey proteins, and especially β-lactoglobulin onto κ-casein (Sawyer, 1969). High heat treatments cause denaturation of whey proteins which associate with κ-casein through disulphide interchange reactions (Hill, 1989). Since their charge is reduced, the denatured proteins associated with casein micelles become susceptible to aggregation when milk is then acidified, which promotes enhanced protein–protein interactions (Lucey et al. 1997). The gelation phenomenon involves disulphide bonds (Hashizume & Sato, 1988; Goddard, 1996) which are responsible for the gel firmness (Goddard, 1996). However, other interactions between proteins can occur, such as hydrogen and hydrophobic bonds, especially at the initial stage of interactions (Haque et al. 1987; Haque & Kinsella, 1988; Jang & Swaisgood, 1990). It is therefore relevant to investigate a possible contribution of weak linkages to the gel structure and firmness.
- Published
- 2003
25. Cellular and molecular imaging by confocal microscopy
- Author
-
Le Tilly, V., Bouhallab, S., Nadia Boutaleb, Thomas Croguennec, Marie-Hélène Famelart, A. Guyomarc'H, Adélaïde Le Grand, Nigen, M., Poncelet, D., Ongmayeb, G., Laboratoire d'Ingénierie des Matériaux de Bretagne (LIMATB), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), and Université de Brest (UBO)-Université de Brest (UBO)
- Subjects
[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
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