Iron Fortification of Milk and Dairy Products

Blood haemoglobin level is used to define anaemia. Thresholds are given by category of age, of sex, and also of physiological status such as pregnancy. For example, the threshold is 120 g L–1 of haemoglobin in blood for a nonpregnant adult woman, 110 for a pregnant woman, 130 for a man older than 15 years, 110 for a child under 5 years… Iron deficiency constitutes the most important worldwide problem of human nutrition. In 2005, 1.62 billions of people were concerned by iron deficiency. Iron deficiency is encountered mostly in poor countries and particularly in Western Pacific, except Australia and New Zealand, in India and Pakistan, in the great majority of countries in Africa, in South Am…

Drug release from calcium and zinc pectinate beads: Impact of dissolution medium composition

The aim of this study was to investigate drug release from calcium and zinc pectinate beads and to understand the impact of medium electrolytes during drug transfer. A potential drug carrier for colonic drug delivery (rutin) was prepared with calcium and zinc pectinate beads and was tested in three different simulated intestinal fluids (pH 7.3) with phosphates (Sorensen’s and Mc Ilvaine’s buffers) and without phosphates (Tris-buffer). According to swelling studies and zinc ions release, it was showed that zinc ions keep adhering to the bead surface. Drug release and swelling behaviour from the two dosage forms depend not only on pH and ionic strength but also on the electrolytes there were …

Transfers of small analytes in a multiphasic stirred fruit yoghurt model

International audience; The transfer of small analytes in a multiphasic stirred fruit yoghurt model, made of a pectin gel aimed to mimic fruit pieces and of a dairy gel done with milk acidified by glucono-δ-lactone hydrolysis, have been studied. The concentration gradients between the pectin gel and the dairy gel were the driving force for the migration of small analytes (i.e. water, protons and colorants). Water migrated from the dairy to the pectin gel, causing modifications in the water content of both gels and an equilibration of their water activity at 0.938±0.003. Inversely, protons migrated from the pectin to the dairy gel. These changes in composition of both gels being likely to ha…

Utilisation d'un polymère à Empreintes Moléculaires pour piéger l'iprodione en milieu aqueux

Investigation of water transfer across thin layer biopolymer films by infrared spectroscopy

International audience; The investigation of the apparent diffusivity of water in thin layer iota-carrageenan-based films by FTIR-ATR spectroscopy clearly evidences the fundamental role of surface properties on water transfer. Water diffusivity in iota-carrageenan based biopolymer films ranges from 0.3 to 1.3 × 10−10 m2 s−1 and is thus 10–100 times lower than that in highly hydrated carrageenan gels. The surface heterogeneity and composition when fat is added strongly influence the diffusivity by modifying the liquid water absorption at the inner surface.This study of diffusing molecules in liquid state is particularly interesting to mimic situations where direct liquid water contact occurs…

Experimental design approach in the synthesis of molecularly imprinted polymers specific for iprodione fungicide

International audience; An experimental design (ED) approach was applied to study the weight of three factors in the synthesis of a molecularly imprinted polymer (MIP) specific for iprodione fungicide. The objective was to obtain a high specific polymer with the best performance of iprodione binding. Thirteen iprodione-imprinted polymers and 13 non-imprinted polymers (NIP) were synthesized according to ED having 3 influencing factors: the polymerization method, the crosslinker nature and the functional monomer type. For each factor, two levels were studied: bulk and precipitation polymerization for the first factor, trimethylolpropane trimethacrylate (TRIM) and ethylene glycol dimethacrylat…

Silica-coated calcium pectinate beads for colonic drug delivery

The aim of this work is to develop novel organic-inorganic hybrid beads for colonic drug delivery. For this purpose, calcium pectinate beads with theophylline are prepared by a cross-linking reaction between amidated low-methoxyl pectin and calcium ions. The beads are then covered with silica, starting from tetraethyoxysilane (TEOS), by a sol-gel process. The influence of TEOS concentration (0.25, 0.50, 0.75 and 1.00 M) during the process is studied in order to modulate the thickness of the silica layer around the pectinate beads and thus to control the drug release. The interactions between the silica coating and the organic beads are weak according to the physicochemical characterizations…

Définir, dénommer, et traduire l'onctuosité : regards croisés sur une propriété gustative et ses dénominations en français, allemand et anglais Beltran-Vidal D., (Dir.) Les Mots de la Santé (2), Affaire(s) de goût(s) , Travaux du CRTT, Lyon, pp. 189-222

International audience

Influence of drug polarity upon the solid-state structure and release properties of self-emulsifying drug delivery systems in relation with water affinity.

To overcome low oral bioavailability of poorly water-soluble drugs, self-emulsifying drug delivery systems (SEDDS) have been noted as a promising strategy. However, incorporation of drugs into SEDDS composed of Gelucire44/14 could induce interactions not yet well understood. The aim of this study was to investigate the influence of drug polarity upon the solid-state structure of SEDDS formulation, particularly in terms of wettability, thermal behaviour and microscopic aspects and their effect upon the release properties of the SEDDS. Model drugs were naproxen and sodium naproxen (10% w/w), two drugs with similar chemical structure but different water solubilities. Both drugs had an effect o…

Flavour release at the interfaces of stirred fruit yoghurt models

Abstract Model matrices consisting of a pectin and a dairy gel were investigated to study the transfer of flavour compounds between the different phases of stirred fruit yoghurt. Using a full factorial experimental design, different parameters (storage temperature, initial flavour concentration in the pectin gel and fat content of the dairy gel) were studied. The kinetics of the migration of flavour compounds between the two gels were investigated using a novel SPME method, where a Carboxen/Polydimethylsiloxane fibre was directly inserted into the pectin gel. Flavour compounds were predominantly retained in the pectin gel and thus, the presence of fat in the dairy gel did not affect their t…

Molecularly imprinted polymer solid phase extraction of fungicides from wine samples

In order to preconcentrate iprodione fungicide in white wine samples, molecularly imprinted polymers (MIPs) specific for iprodione were synthesized using two polymerization approaches: precipitation (MIPp) and bulk polymerization (MIPb). A comparison of the performance of the MIPs and the corresponding non-imprinted polymers (NIPs) was conducted in batch studies. In this case, the MIPp revealed better recognition properties toward iprodione in wine samples than the MIPb. The MIPp and MIPb were then used as sorbents on solid phase extraction cartridges (MISPEp and MISPEb consecutively) in order to pre-concentrate iprodione from white wine samples. The optimization of the MISPE elution step w…

Meat vegetable analogues: real competitors of animal foods ? : Are vegetable analogues of meat real competitors: elements of comparisons

Requirement for a global design to remove fat from flavoured yoghurts

Abstract The low-fat dairy desserts are generally not so much appreciated as the corresponding products containing fat because of altered flavour and texture characteristics. A review of the influence of fat on these aspects is proposed. Some methods used to correct for flavour imbalances also decrease the texture quality.

Iron intake among Lebanese women: sociodemographic factors, iron-rich dietary patterns, and preparation of hummus, a Mediterranean dish

Background: Plant-based foods such as hummus are alternative to animal protein, and when properly pre-pared, they help to alleviate nutritional iron deficiency that leads to anemia, a global health problem. Objective: The objective was to assess iron intake among Lebanese women and related participant’s charac-teristics, discern iron-rich dietary patterns, evaluate their association with nutrients intake and participant’s sociodemographic characteristics, and identify the women preparing hummus traditionally and properly for an enhanced iron bioavailability. Design: A cross-sectional study of 400 Lebanese women (18–74 years old) was conducted in Lebanon. Data from a questionnaire, including…

Fast and direct analysis of oxidation levels of oil-in-water emulsions using ATR-FTIR.

International audience; Oxidation of omega-3 fatty acids is a major limitation on its enrichment in food and beverages. An efficient and simple method to monitor lipid oxidation in complex systems is essential to limit lipid oxidation during formulation and processing. Fish oil-in-water emulsions (20% v/v) were exposed to iron or free radical initiated oxidation. Conjugated dienes (CDs) were rapidly measured using a previously developed fat extraction method. Fourier transform infrared (FTIR) spectroscopy has been used to directly record chemical changes occurring during oxidation. Variations were noticed in different spectral regions despite the presence of broad water bands near 3400 and …

Antioxidant Properties of Ergosterol and Its Role in Yeast Resistance to Oxidation

International audience; Although the functions and structural roles of sterols have been the subject of numerous studies, the reasons for the diversity of sterols in the different eukaryotic kingdoms remain unclear. It is thought that the specificity of sterols is linked to unidentified supplementary functions that could enable organisms to be better adapted to their environment. Ergosterol is accumulated by late branching fungi that encounter oxidative perturbations in their interfacial habitats. Here, we investigated the antioxidant properties of ergosterol using in vivo, in vitro, and in silico approaches. The results showed that ergosterol is involved in yeast resistance to tert-butyl h…

Interactions between bacterial surfaces and milk proteins, impact on food emulsions stability

Bacteria possess physicochemical surface properties such as hydrophobicity, Lewis acid/base and charge which are involved in physicochemical interactions between cells and interfaces. Moreover, food matrices are complex and heterogeneous media, with a microstructure depending on interactions between the components in media (van der Waals, electrostatic or structural forces, etc.). Despite the presence of bacteria in fermented products, few works have investigated how bacteria interact with other food components. The objective of the present study was to determine the effects of the surface properties of lactic acid bacteria on the stability of model food emulsions. The bacteria were added t…

Effect of oxidoreduction potential and of gas bubbling on rheological properties and microstructure of acid skim milk gels acidified with glucono-delta-lactone

Milk oxidoreduction potential was modified using gases during the production of a model dairy product and its effect on gel setting was studied. Acidification by glucono-delta-lactone was used to examine the physicochemistry of gelation and to avoid variations due to microorganisms sensitive to oxidoreduction potential. Four conditions of oxidoreduction potential were applied to milk: milk was gassed with air, nongassed, gassed with N(2), or gassed with N(2)H(2). The rheological properties and microstructure of these gels were determined using viscoelasticimetry, measurement of whey separation, and confocal laser scanning microscopy. It appeared that a reducing environment led to less-aggre…

A New pH-Dependent Macrocyclic Rhodamine B-Based Fluorescent Probe for Copper Detection in White Wine

For efficiently measuring copper (II) ions in the acidic media of white wine, a new chemosensor based on rhodamine B coupled to a tetraazamacrocyclic ring (13aneN4CH2NH2) was designed and synthesized by a one-pot reaction using ethanol as a green solvent. The obtained chemosensor was characterized via NMR, UV and fluorescent spectra. It was marked with no color emission under neutral pH conditions, with a pink color emission under acidic conditions, and a magenta color emission under acidic conditions where copper (II) ions were present. The sensitivity towards copper (II) ions was tested and verified over Ca2+, Ag+, Zn2+, Mg2+, Co2+, Ni2+, Fe2+, Pb2+, Cd2+, Fe3+, and Mn2+, with a detection…

Water sorption isotherms of molecularly imprinted polymers. Relation between water binding and iprodione binding capacity

International audience; Molecularly imprinted polymers are often used in aqueous medium in order to recognize specifically a target molecule. The molecular recognition is usually based on hydrogen bonding. In this case, water molecule presents a serious competition towards the target molecule. In this study, the water sorption by molecularly imprinted polymers was studied in aqueous medium. The molecularly imprinted polymers were specific for iprodione fungicide and were prepared using a 24 full factorial experimental design. They were synthesized using EGDMA or TRIM as crosslinker, methacrylamide or styrene as functional monomer and using bulk or precipitation polymerization. The water sor…

Effects of heat treatment and acid-induced gelation on aroma release from flavoured skim milk

Abstract Time dependent aroma release was studied in skim milk, heated skim milk as well as in acid-induced gels derived from them using static headspace – gas chromatography analysis. A variable order kinetic model was fitted to experimental data and was used to determine headspace equilibrium concentration and initial rates of release. When compared to water, retention in milk based matrices was increased for hydrophobic aroma compounds, while it was decreased for more hydrophilic volatiles. Acid gelation reduced the initial rate of aroma release by a factor varying from 2.0 to 3.8, depending on the compound. Positive deviation from the first order kinetics was observed and suggests that …

Ergosterol biosynthesis: a fungal pathway for life on land?

International audience; Sterols, essential lipids of most eukaryotic cells, ensure important structural and signaling functions. The selection pressure that has led to different dominant sterols in the three eukaryotic kingdoms remains unknown. Here, we investigated the influence of the progression in the different steps of the ergosterol biosynthetic pathway (EBP) on the yeast resistance to transitions from aqueous to aerial media, typical perturbations of the higher fungi habitats. Five mutants of the EBP (ergΔ), accumulating different sterol intermediates in the EBP, and the wild-type (WT) strain were exposed to drying under atmospheric air or nitrogen and wetting. Results show that the …

Structure of calcium and zinc pectinate films investigated by FTIR spectroscopy

International audience; Calcium and zinc pectinate gels were prepared using a method which allowed calcium or zinc to diffuse from the cross-linking solution through a dialysis membrane to form a gel with amidated low-methoxyl pectin. The gel thus obtained was then dried, and the film structure was studied using FTIR spectroscopy as a function of the cation content (0%, 5%, 10%, and 15% w/v). Important consideration was given to the three functional groups (amide, carboxyl ester, and carboxylate groups) present in the pectin. When the zinc content was increased, the three wavenumber values corresponding to these three functional groups did not change significantly, while for calcium pectina…

Le fer dans les aliments, la lutte contre le déficit de fer

Effect of pea proteins extraction and vicilin/legumin fractionation on the phase behavior in admixture with alginate

Abstract Soluble and natural mixed pea proteins (PP) were extracted from defatted pea seeds according to acidic precipitation (PPP) or ultrafiltration/diafiltration (PPDF) procedures. The isolates contained proteins with a low level of denaturation. Mixed pea globulins isolates presented quite similar solubility and thermal profiles, also a similar polypeptide composition. Vicilin/convicilin 7S (Vic) and legumin 11S (Leg) fractions were obtained by batch chromatography using a salt gradient for the elution. Several incompatible systems were built by mixing the pea proteins with an anionic polysaccharide (sodium alginate, SA), when biopolymers were both negatively charged. Most of mixtures e…

Probing Protein−Membrane Interactions Using Solid Supported Membranes

International audience; Tethered bilayer lipid membranes have been used as a model system to mimic the interactions between the whey protein β-lactoglobulin and a lipid interface. The approach allowed for a detailed study of the lipid-protein interactions, the results being of possible importance in food and cosmetic applications. For such applications, lipid-protein interactions and the interfacial behavior are vital factors in controlling and manipulating process conditions such as emulsion stabilization and gelification. Lipid composition as well as the structural properties of the protein governed their interactions, which were probed by a combination of surface plasmon spectroscopy, ne…

Electrochemical modifications of proteins: disulfide bonds reduction

International audience; Electrochemical reduction of lysozyme disulfide bonds was achieved at pH between 10 and 11.Below pH 10, no disulfide bond cleavage was observed. At pH higher than 12, the cleavage of disulfide bonds is essentially due to hydrolysis. The addition of denaturant considerably enhanced the performance of the electrochemical device.

The impact of cooking on meat microstructure studied by low field NMR and Neutron Tomography

International audience; We studied the impact of temperature of cooking on meat microstructure. The cooking temperature was verified by calorimetry, showing the disappearance of endothermic peaks when cooking temperature was increased. These observations correspond to the denaturation of different protein fractions at specific temperatures. 1H-low field NMR and neutron tomography were used to further understand the relationship between the observed protein denaturation and changes in meat microstructure after heating. Hahn’s echo and solid echo NMR sequences were applied to observe fast relaxation time corresponding to rigid protons. These protons were found to be associated with pools of p…

Protein aggregation induced by phase separation in a pea proteins–sodium alginate–water ternary system

Abstract The physicochemical properties of a native, globular plant protein–linear anionic polysaccharide aqueous system at 20 °C were investigated in conditions where biopolymers carry a net negative charge (pH 7.2, 0.1 M NaCl). The pea proteins–sodium alginate mixtures showed a phase separation mainly by thermodynamic incompatibility, characterized at both the macroscopic and microscopic scale. Phase diagram was established and confocal laser scanning microscopy (CLSM) provided accurate data on the microstructure morphology of the system, regarding its phase behavior. In admixture, sodium alginate induced a protein aggregation, certainly by a local depletion of the polysaccharide. Protein…

Modified arabinoxylan-based films

Abstract Oxygen plasma and electron beam irradiation were used to graft hydrophobic substances and by this way, to reduce water vapor permeability (WVP) of arabinoxylan-based (AX-based) films. Stearyl acrylate (SA) and stearyl methacrylate (SM) were used as reactive monomers. The homogeneous AX-based films, which were pre-activated by oxygen plasma and impregnated with a solution of SA before being exposed to an electron beam (EB), had contact angles that increased from 71° (untreated films) to 122° (treated films). A decrease of about 24% in the WVP was obtained and new chemical groupings were observed on the FTIR spectra of these films. Acrylate monomers were also dispersed into the arabi…

Sensor and device for detecting an analyte in a liquid

Chapitre 12. L’apport sociétal de la pasteurisation des aliments face à son coût énergétique

International audience

Meat substitutes: formulations and comparative analysis

The nutritional quality of animal products is often overlooked in our consumers' imaginations. Sustainability for example, must takeinto account sustainability for humans, starting with meeting their nutritional needs as naturally as possible. For starters, the protein intake, inquantity per 100 g of edible food (usually cooked), greatly exceeds those of vegan equivalents, whether they are meat analogues made fromvegetable proteins or vegetarian dishes reputed to be sources of protein (chickpeas, hummus, lentils, tofu etc.). In addition, it is clear that animalproducts are protein sources of high nutritional quality (DIAAS  80) unlike vegetarian equivalents (DIAAS  80). Animal proteins ar…

Allergies et intolérances alimentaires : Fiches pratiques sur les 14 allergènes majeurs

International audience; Les allergies et les intolérances alimentaires représentent un enjeu majeur pour l’industrie agroalimentaire. Présenté sous forme de fiches pratiques, cet ouvrage a pour objectif d’apporter une vision claire et synthétique sur le sujet. Il présente notamment les 14 allergènes majeurs et détaille pour chacun d’eux : la nature et les causes de l’allergie ; les préparations courantes dans lesquelles on le trouve, ses rôles nutritif et technologique ; les moyens pour le remplacer, selon que l’on souhaite conserver le goût, les valeurs nutritives ou simplement l’apparence.Les questions d’hygiène et de la maîtrise du risque sont également abordées, et une démarche pratique…

Method for eliminating microorganisms present in and/or at the surface of a material to be decontaminated

The present invention concems a method for eliminating microorganisms present in and/or at the surface of a material to be decontaminated comprising a step of irradiating said material to be decontaminated with radiation consisting of at least two light beams a1and a2 directed onto said material, the two light beams a1 and a2 respectively having a wavelength λ1 and λ2 of between 380 and 420nm.

Effect of apolar phase dielectric constant on interfacial properties of β-lactoglobulin (dielectric constant and interfacial properties of β-lactoglobulin)

International audience; In this work, we hypothesized that the difference in the dielectric constant value existing between two non-miscible phases such as oil and water could be partially responsible for both protein unfolding and reorganization of the protein structure at the interface. So, we replaced the oil phase, whose dielectric constant value is 2, by organic solvents chosen for both their non-miscibility with water and their range of dielectric constant values higher (range 6.1-7.2) than that of oil. Using a dynamic drop tensiometer, we studied both surface activity and viscoelastic properties of the milk protein at various interfaces. The aqueous phase (pH7; 25°C) contained the co…

Structural studies of adsorbed protein (betalactoglobulin) on natural clay (montmorillonite)

International audience; In this work, the adsorption of a small globular protein (betalactoglobulin, BLG), on a natural montmorillonite clay (Mt) was investigated in acidic buffer (pH = 3). The combination of different characterization techniques such as zetametry, X-ray diffraction, transmission electronic microscopy, fluorescence and solid state nuclear magnetic resonance spectroscopies shed light on the interaction mechanism between the clay mineral and the proteins. For low BLG concentration, a slight increase of the interlayer spacing of the clay mineral was noticed as well as structural changes of the protein. In contrast, as the concentration of BLG increased, the adsorption led to a…

Meat substitutes: formulations and comparative analysis: micronutrient intakes

The nutritional quality of a food is not only assessed by its protein intake and the quality of proteinintake, but also by its intake of trace elements. Animal products are the only sources of vitamin B12, apartfrom pharmaceutical food supplements. The amounts of other B vitamins are much greater in meatproducts: 4 to 6 times higher for vitamin B1, 2 to 20 times for vitamin B2, 5 to 30 times for vitamin B3, 2 to 12 times for vitamin B5, 2 to 100 times for vitamin B5, as much as 30 times for vitamin B6. Less markedly,the mineral content is also higher for cooked meat or cooked meat products compared to a ready-to-eatvegetable analogue: from 2 to 9 times more zinc in meat products than in ana…

Attachment of chloride anion to sugars: mechanistic investigation and discovery of a new dopant for efficient sugar ionization/detection in mass spectrometers.

International audience; A new method for efficient ionization of sugars in the negative-ion mode of electrospray mass spectrometry is presented. Instead of using strongly hydrophobic dopants such as dichloromethane or chloroform, efficient ionization of sugars has been achieved by using aqueous HCl solution for the first time. This methodology makes it possible to use hydrophilic dopants, which are more appropriate for chromatographic separation techniques with efficient sugar ionization and detection in mass spectrometry. The interaction between chloride anions and monosaccharides (glucose and galactose) was studied by DFT in the gas phase and by implementing the polarizable continuum mode…

The chemodiversity of wines can reveal a metabologeography expression of cooperage oak wood

Wine chemical compositions, which result from a complex interplay between environmental factors, genetic factors, and viticultural practices, have mostly been studied using targeted analyses of selected families of metabolites. Detailed studies have particularly concerned volatile and polyphenolic compounds because of their acknowledged roles in the organoleptic and therapeutic properties. However, we show that an unprecedented chemical diversity of wine composition can be unraveled through a nontargeted approach by ultrahigh-resolution mass spectrometry, which provides an instantaneous image of complex interacting processes, not easily or possibly resolvable into their unambiguous individu…

Protein-lipid interactions at the air-water interface.

International audience; Protein−lipid interactions play an important role in a variety of fields, for example in pharmaceutical research, biosensing, or food science. However, the underlying fundamental processes that govern the interplay of lipids and proteins are often very complex and are therefore studied using model systems. Here, Langmuir monolayers were used to probe the interaction of a model protein with lipid films at the air−water interface. The protein β-lactoglobulin (βlg) is the major component in bovine milk serum, where it coexists with the milk fat globular membrane. During homogenization of milk, βlg adsorbs to the interface of lipid fat globules and stabilizes the oil-in-…

The Importance of Developing Electrochemical Sensors Based on Molecularly Imprinted Polymers for a Rapid Detection of Antioxidants

International audience; This review aims to pin out the importance of developing a technique for rapid detection of antioxidants, based on molecular imprinting techniques. It covers three major areas that have made great progress over the years in the field of research, namely: antioxidants characterization, molecular imprinting and electrochemistry, alone or combined. It also reveals the importance of bringing these three areas together for a good evaluation of antioxidants in a simple or complex medium, based on selectivity and specificity. Although numerous studies have associated antioxidants with molecular imprinting, or antioxidants with electrochemistry, but even electrochemistry wit…

Lemon Juice, Sesame Paste, and Autoclaving Influence Iron Bioavailability of Hummus: Assessment by an In Vitro Digestion/Caco-2 Cell Model

Hummus, an iron-containing plant-based dish mainly made from chickpea pur&eacute

Substitution of carcinogenic solvent dichloromethane for the extraction of volatile compounds in a fat-free model food system

International audience; Dichloromethane is known as a very efficient solvent, but, as other halogenated solvents, is recognized as a hazardous product (CMR substance). The objective of the present work is to propose substitution solvent for the extraction of volatile compounds. The most important physico-chemical parameters in the choice of an appropriate extraction solvent of volatile compounds are reviewed. Various solvents are selected on this basis and on their hazard characteristics. The selected solvents, safer than dichloromethane, are compared using the extraction efficiency of volatile compounds from a model food product able to interact with volatile compounds. Volatile compounds …

Utilisation of pectin coating to enhance spray-dry stability of pea protein-stabilised oil-in-water emulsions

International audience; In this study, development of pea (Pisum sativum) protein stabilised dry and reconstituted emulsions is presented. Dry emulsions were prepared by spray-drying liquid emulsions in a laboratory spray-dryer. The effect of drying on the physical stability of oil-in-water emulsions containing pea protein-coated and pea protein/pectin-coated oil droplets has been studied. Oil-in-water emulsions (5 wt.% Miglyol 812 N, 0.25 wt.% pea protein, 11% maltodextrin, pH 2.4) were prepared that contained 0 (primary emulsion) or 0.2 wt.% pectin (secondary emulsion). The emulsions were then subjected to spray-drying and reconstitution (pH 2.4). The stability of the emulsions to dry pro…

Définir, dénommer et traduire l'onctuosité : regards croisés sur une propriété gustative et ses dénominations en français, anglais et allemand

International audience; Un simple coup d'œil sur les rayons crèmerie d'un supermarché ou sur les prospectus publicitaires suffit à s'en convaincre : onctueux est un attribut fort prisé en marketing alimentaire. Un test rapide sur google le confirme par ailleurs : pour les seules structures N + A, le moteur de recherche fournit une multitude d'occurrences pour ce domaine avec des syntagmes comme fromage blanc onctueux, potage onctueux mais aussi bûche de Noël au cœur onctueux, riz onctueux ou encore beurre de pomme onctueux. L'objectif de cette contribution est ainsi d'interroger les multiples emplois de l'adjectif onctueux en français et d'en envisager les équivalents possibles en anglais e…

Effect of iron chelates on oil–water interface, stabilized by milk proteins: The role of phosphate groups and pH. Prediction of iron transfer from aqueous phase toward fat globule surface by changes of interfacial properties

International audience; Iron incorporated into food systems induces oxidation and precipitation. The consequences are reduced bioavailability and a functional modification of other food components such as proteins. The iron-chelates such as ferrous bisglycinate represent a possibility to avoid side effects, since the iron is protected. The aim of this study is to investigate the effects of iron-chelates compounds on the properties of an oil/water interface stabilized by caseinate or β-lacotoglobulin, under environmental conditions at 20 °C. Analyses were performed using dynamic drop tensiometry during 5000 s. The aqueous bulk phase is an imidazole/acetate buffer (0.1 M), containing 0.4 × 10…

In situ Pesticide Detection in Food Processing by Microwave Transduction Combined with Molecularly Imprinted Polymers

International audience; Since 2005, the microwave transduction coupled with a sensitive material is devoted to gas detection. In this work, we demonstrate the possibility to detect liquid pollutant (pesticide, fungicide) for food-processing industry. The principle is based on the interaction of the pollutant with a sensitive material within a microwave structure. The sensor is submitted to an electromagnetic excitation in wideband frequencies (GHz) and presents a quantitative response to liquid pollutant expositions at low concentration. The retained sensitive material is a molecularly imprinted polymer (MIP) specific to the pesticide targeted in a model wine. The coupling with this materia…

Ascorbic Acid Oxidation in Sucrose Aqueous Model Systems at Subzero Temperatures

The reduction of Tempol by ascorbic acid in concentrated sucrose solutions was measured by electron paramagnetic resonance (EPR) at temperatures ranging from 16 to −16 °C. This method allowed the determination of the rate constants (k) of this fast reaction, by recording the Tempol reduction as a function of time. The two reactants were initially separated and had to migrate for the reaction to occur. The experimental findings were compared with predicted values according to the equation for diffusion-controlled reaction proposed by Atkins. The experimental reaction rate constants were observed to be lower than the calculated ones. However, the experimental values were found to be controlle…

Physico-chemical characterisation of a non-conventional food protein source from earthworms and sensory impact in arepas

International audience; This study aimed to characterise a non-conventional protein source: a powder made from earthworms, and to evaluate its potential use as human food. The way it was prepared led to low solubility and wide particle size distribution. Sensory analysis was used to assess the acceptability and the organoleptic properties of maize-based pan-cakes fortified with this novel protein powder. Satisfying products were obtained with a substitution level of 5.5% (w/w) earthworm powder in pan-cakes. GC-MS allowed the identification of more than seventy volatile compounds that may be responsible for the off-odour of the powder. The most abundant chemical groups found in the volatile …

Influence of the composition and the structure of different media on the release of aroma compounds

International audience; The release of 2-nonanone and hexenol (hex-4-en-3-ol) was studied in model media with different structures and compositions: water, a gel of $\beta$-lactoglobulin, gelified or non-gelified emulsions (5.0% Miglyol, 6.9% $\beta$-lactoglobulin; the gelation was realized by heating) and milk. The aroma compounds were analyzed by gas chromatography. A strong influence of the nature of the volatile compound on its behavior towards the food matrix was observed: in the case of 2-nonanone, a hydrophobic compound (log P = 2.9) with a relatively high vapor-water partition coefficient (Kmol = 33.6), the release was greatly influenced by the composition and the structure of the m…

Expressing forest origins in the chemical composition of cooperage oak woods and corresponding wines by using FTICR-MS.

A non-targeted, ultra-high-resolution mass spectrometric, direct analysis of oak-wood extracts from two species (Quercus robur L. and Quercus petraea Liebl.) from three French forests, and of a wine aged in barrels derived therefrom has been performed to identify families of metabolites that could discriminate both the species and the geographical origin of woods. From 12 T ultra-high-resolution Fourier transform ion cyclotron resonance mass spectra of wood extracts, hundreds of mass signals were identified as possible significant biomarkers of the two species, with phenolic and carbohydrate moieties leading the differentiation between Q. robur and Q. petraea, respectively, as corroborated …

Binding characteristics of molecularly imprinted polymers based on fungicides in hydroalcoholic media

An iprodione-imprinted polymer was prepared by copolymerization of methacrylamide and ethylene glycol dimethacrylate using a noncovalent imprinting approach. Methacrylamide was chosen using molecular dynamics simulations. To concentrate iprodione from hydro-alcoholic solutions, batch sorption of iprodione on the imprinted polymer were conducted. The equilibrium time for iprodione sorption is 20 min, and the corresponding kinetic mechanism follows the pseudo-second order indicating a strong interaction between iprodione and the imprinted polymer. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to fit the isotherm of iprodione sorption. The imprinted polymer was found to be mo…

Viscoelastic properties of acid milk gel as affected by fat nature at low level

International audience; The viscoelastic properties of acid milk gels containing small amounts of different fats were investigated. Skim milk was reconstituted from ultra low-heat skim milk powder and emulsions made with 2% (v/v) sunflower oil, olive oil, groundnut oil, or anhydrous milk fat using a pressure homogenizer. Acidification at 20 °C for 14 h to pH ∼4.6 was achieved by adding glucono-δ-lactone to the emulsion. Stress relaxation testing enabled determination of the firmness and the solid-like properties, i.e., elasticity. Regardless of the physical state of the fat, emulsion gels exhibited higher firmness than fat-free gels, despite the low fat level used. The firmness of the gels …

Chapter 6: Iron fortification of milk and dairy products

International audience; Anaemia is a worldwide health problem, mainly due to the low availability of iron in food products. The bioavailability of heme iron is far greater than the one of non-heme iron. Dairy products consumed together with iron-rich food decrease the availability of iron but the competition between calcium and iron ions is not clear. Iron is naturally present in milk under the form of lactoferrin, but lactoferrin may undergo thermal denaturation during process. Iron salts, cheaper than lactoferrin, are preferably used to fortify dairy products. The bioavailability of iron depends on the solubility and the dissociation constant of the salts. To administer iron as a medicine…

Effect of gases on biochemical stabilization

International audience; Lipid or protein are sensitive to peroxidation and inert gas limit or stop adulterations. Unsaturated lipids are peroxided by ground state dioxygen in presence of catalysts (iron, enzymes) or after thermal dissociation of C=C bond, and by excited state dioxygen without any assistance (photo-oxidation). Inerting fragile oils by bubbling with dinitrogen or carbon dioxide that are soluble gas in oil slows oxidation process during storage or frying. In a same way, limit the oxidation of the tryptophan residues of protein is possible by reducing oxygen content. Oxidation leads also to oxidation of thiol in disulfide, which induced protein cross-linked and decay of functio…

Pourquoi le fer est indispensable à notre santé

On ne s’en rend généralement pas compte, mais le fer est un atome essentiel à la vie. Chimiquement parlant, il appartient à la famille des métaux dits « de transition », capables d’échanger facilement des électrons : pour traduire cela en termes simples, cela signifie que cet atome donne aux molécules biologiques auxquelles il est attaché une grande réactivité et leur confère des propriétés chimiques importantes (d’oxydo-réduction par exemple) et, par voie de conséquence, des activités biologiques essentielles...

Protein Thermal Denaturation of Beef Muscle: Neutron Imaging and spectroscopies

International audience; Open Food System is an industrial innovation project having as goal the development of “smart” domestic appliances, which can pilot cooking process of meat and fish without any human intervention. My Ph.D research belongs to that huge project with the purpose to follow the evolution of cooking process at molecular scale, describing biochemical reactions occurring among muscle constituents and associating them to macroscopic characteristics (texture, colour, …). Thermal denaturation of muscle proteins was studied by spectroscopy technics, able to observe their conformational modifications due to the application of several temperature/time conditions. Spectroscopy sign…

Carence en fer : comment y remédier par son alimentation

Le fer est indispensable à notre bonne santé, c’est un fait. Mais comment nous assurer que notre alimentation nous apporte ce dont nous avons besoin ? Commençons par détruire un mythe… Les épinards de Popeye ne sont pas riches en fer. La teneur n’y est que 2,1 mg par 100 g d’épinards frais...

Data from: Ergosterol biosynthesis: a fungal pathway for life on land?

Sterols, essential lipids of most eukaryotic cells, ensure important structural and signaling functions. The selection pressure which has led to different dominant sterols in the three eukaryotic kingdoms remains unknown. Here we investigated the influence of the progression in the different steps of the ergosterol biosynthetic pathway (EBP) on the yeast resistance to transitions from aqueous to aerial media, typical perturbations of the higher fungi habitats. Five mutants of the EBP (ergΔ), accumulating different sterol intermediates in the EBP, and the WT strain were exposed to drying under atmospheric air or nitrogen and wetting. Results show that the progression in the EBP parallels an …