Transport parameters for aroma compounds through i-carrageenan and sodium alginate-based edible films

In an effort to produce more environmentally friendly materials, renewable and biodegradable biopolymers have been investigated as coating materials. Edible films obtained from i-carrageenan and sodium alginates have good mechanical characteristics, are emulsion stabilizers, and decrease oxygen transfer. The addition of lipids to form emulsified films decreases the water vapour transfer and could be used to encapsulate active substances or aroma compounds. The aim of this work was to measure permeability, sorption and diffusion coefficient of the n-hexanal and D-limonene aroma compounds through emulsified (wf) and non-emulsified (wof) i-carrageenan and sodium alginate-based films to finally…

How composition and process parameters affect volatile active compounds in biopolymer films

Abstract Active edible films based on chitosan and containing an active aroma compound have been investigated. The influence of the composition of the film forming solution (solvent, plasticizers, nanoparticles, emulsifiers and aroma traps) and process parameters (temperature and viscosity) on drying kinetics, water content, colour, aroma compound retention and partition coefficient was studied. Solvent evaporation rate was increased by addition of ethanol. Water evaporation was delayed by glycerol. The aroma retention during film drying was directly related to the water content. The drying temperature had opposite influences according to the composition of the solvent and additives. Increa…

Transfer of Water and Volatiles at Interfaces: Application to Complex Food Systems

International audience; During processing, storage and consumption, mass transfer of various small molecules (water, gases, flavour compounds or other solutes) occurs between the different phases in complex food products, or between complex food and its surroundings. These mass transfers can lead to physical or chemical changes and thus induce food quality modifications.The objective of this paper is to better understand the behaviour of small molecules at the interfaces, especially in model heterogeneous food systems. Different techniques have been designed to characterize mass transfers of these small molecules and their effects on food properties. In particular, techniques such as rotati…

Papers and Boards

Methyl cellulose-based edible films and coatings I. Effect of plasticizer content on water and 1-octen-3-ol sorption and transport

Edible films were prepared from methyl cellulose with various concentrations of poly(ethylene glycol) 400 (PEG400) used as a plasticizer. Water vapour and 1-octen-3-ol (an aroma compound) were selected as hydrophilic and hydrophobic volatile penetrants respectively. Their solubility and permeability through methyl cellulose-based edible films were studied using gas chromatography methods. Whatever penetrant was used, the flux increased with the PEG400 content. Transfer behaviour, i.e., the order of increased magnitude of the transfer rate, strongly depends on the nature of the volatile compound. However, water sorption only depends on the PEG400 content whereas the aroma compound sorption i…

Techniques to measure sorption and migration between small molecules and packaging. A critical review

The mass transfer parameters diffusion and sorption in food and packaging or between them are the key parameters for assessing a food product's shelf-life in reference to consumer safety. This has become of paramount importance owing to the legislations set by the regulated markets. The technical capabilities that can be exploited for analyzing product–package interactions have been growing rapidly. Different techniques categorized according to the state of the diffusant (gas or liquid) in contact with the packaging material are emphasized in this review. Depending on the diffusant and on the analytical question under review, the different ways to study sorption and/or migration are present…

Carvacrol affects interfacial, structural and transfer properties of chitosan coatings applied onto polyethylene

Different chitosan coating solutions were tested with the aim of investigating their adhesion and wettability onto polyethylene film to improve packaging performance and provide antimicrobial properties. Surface wetting kinetics was monitored by contact angle measurements. Addition of ethanol and carvacrol improved wettability and adhesion of the thin chitosan layer. Structure, water vapour, O2, CO2 and air permeabilities of self supported chitosan films and coated polyethylene were determined. The formation of a thin chitosan layer on polyethylene improved gas barrier properties decreasing the Permeability Coefficient for oxygen and carbon dioxide ( [Formula: see text] , [Formula: see text…

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…

Antioxidant Activity and Release Kinetics of Caffeic and p-Coumaric Acids from Hydrocolloid-Based Active Films for Healthy Packaged Food

International audience; Sustainable hydrocolloid-based films containing natural antioxidants, caffeic and p-coumaric acids at different concentrations of 0.5%, 1%, 5%, and 10% w/w of polymers, were designed for packing fatty foods. Antioxidant activities and kinetics for all film formulations were assessed using radical scavenging activity (DPPH), reducing power, and iron chelating ability. Release kinetics of the antioxidants from the films into a food simulant (96% ethanol) were analyzed. The intermolecular interactions between antioxidants and polymers chains were assessed by Fourier transform infrared attenuated total reflectance (FTIR-ATR) and related to the film properties. Antioxidan…

Transferts de matière au travers des emballages au contact de produits alimentaires

Le point sur des recherches dans le domaine des transferts de matière au travers des emballages : impact sur la qualité du produit, causes de ces transferts.

From macroscopic to molecular scale investigations of mass transfer of small molecules through edible packaging applied at interfaces of multiphase food products

Abstract This paper presents a multi-scale approach to investigate mass transfer properties of edible films that integrates some published data and new original results. The transport of small molecules, such as water, between the different parts of multiphase food products leads to quality deterioration and thus requires the use of barrier edible films or coatings. Therefore, it is necessary to characterise the properties of both food and edible barriers, like the diffusivities of their respective migrants. Surface properties characterisation of edible films, composed of an iota-carrageenan matrix in association with a high melting point fat was investigated by goniometry and allows the de…

Protein and glycerol contents affect physico-chemical properties of soy protein isolate-based edible films

Abstract This study was conducted to determine the effect of both soy protein and glycerol contents on physico-chemical properties of soy protein isolate-based edible (SPI) films. The aim of this study was to better understand the influence of SPI and GLY contents on the behavior of the physico-chemical properties of soy protein isolate-based films. Films were casted from heated (70 °C for 20 min) alkaline (pH 10) aqueous solutions of SPI at 6, 7, 8, and 9 (w/w %), glycerol (50%, w/w, of SPI) and SPI at 7 (w/w %), glycerol (40, 60, 70 %, w/w of SPI). Water vapor permeability (WVP), was measured at 25 °C and for four different relative humidities (30–100%, 30–84%, 30–75%, 30–53%). Surface pr…

Importance of surface tension characterization for food, pharmaceutical and packaging products: a review.

This article reviews the various theoretical approaches that have been developed for determination of the surface tension of solids, and the applications to food industrial products. The surface tension of a solid is a characteristic of surface properties and interfacial interactions such as adsorption, wetting or adhesion. The knowledge of surface tension is thus of great interest for every domain involved in understanding these mechanisms, which recover a lot of industrial investigations. Indeed, it is the case for the packaging industry, the food materials science, the biomedical applications and the pharmaceutical products, cleaning, adhesive technology, painting, coating and more gener…

Corrigendum to “Influence of temperature and NaCl on the release in aqueous liquid media of aroma compounds encapsulated in edible films” [Journal of Food Engineering 108 (2012) 30–36]

Effect of relative humidity on carvacrol release and permeation properties of chitosan based films and coating

International audience; The influence of water vapour conditions on mass transport and barrier properties of chitosan based films and coatings were studied in relation to surface and structural properties. Water contact angles, material swelling, polymer degradation temperature, barrier properties (PO2, PCO2, WVP) and aroma diffusion coefficients were determined. The solvent nature and the presence of carvacrol influenced the surface and structural properties and then the barrier performance of activated chitosan films. Increasing RH from 0% to 100% led to a significant increase in material swelling. The plasticization effect of water was more pronounced at high humid environment, while at …

Effect of modified starch or maltodextrin incorporation on the barrier and mechanical properties, moisture sensitivity and appearance of soy protein isolate-based edible films

Abstract This work aimed to study the effect of starch (acetylated di-starch phosphate and starch acetate) and maltodextrin (DE 10.2 and DE 15.6) on the properties of soy protein isolate (SPI) films. Films were cast from heated (70 °C for 20 min) alkaline (pH 10) aqueous solutions of soy protein isolate (8%) containing glycerol (50% of SPI) as a plasticizer and starch or maltodextrin (20% of SPI). For all types of films, water vapor sorption kinetics during 24 h at 25 °C and 75% relative humidity (RH), diffusion coefficient of water vapor, water vapor permeability at 25 °C for two relative humidity differentials (40–75 and 40–100%), tensile strength and elongation at break, color and micros…

Effect of ferulic acid and α-tocopherol antioxidants on properties of sodium caseinate edible films

Edible films, based on sodium caseinate containing three different concentrations of ferulic acid or alpha-tocopherol (20, 40 and 60 mg/g sodium caseinate), were obtained in order to evaluate the effect of these compounds on properties of the caseinate matrices. Special emphasis was placed on their effect on the films' oxygen barrier properties, which are decisive in the prevention of the oxidation of foods containing lipids. Films were characterized as to their tensile, optical and surface properties as well as their barrier properties to water vapor, oxygen and aroma compounds (n-hexanal and n-hexanol). Ferulic acid was more efficient at reducing oxygen and n-hexanal permeability than alp…

Protection of active aroma compound against moisture and oxygen by encapsulation in biopolymeric emulsion-based edible films.

International audience; Edible films made of ι-carrageenans display interesting advantages: good mechanical properties, stabilization of emulsions, and reduction of oxygen transfers. Moreover, the addition of lipids to ι-carrageenan-based films to form emulsified films decreases the transfer of water vapor and can be considered to encapsulate active molecules as flavors. The aim of this study was to better understand the influence of the composition and the structure of the carrageenan-based film matrices on its barrier properties and thus on its capacity to encapsulate and to protect active substances encapsulated. Granulometry, differential scanning calorimetry, and Fourier transform infr…

BIOPOLYMERS USED AS EDIBLE COATING TO LIMIT WATER TRANSFER, COLOUR DEGRADATION AND AROMA COMPOUND 2-PENTANONE LOST IN MEXICAN FRUITS

Low preservation of typical fruits in countries with warm weather represents a limitation to export. A recently proposed method to increase shelf-life of fresh guava, is the application of biopolymers as edible coatings. This research involves the use of biopolymers of microbial origin obtained with low cost nutrients, to prepare edible coatings applied on mexican guava and apricot. Dextrans obtained by fermentation with Leuconostoc mesenteroides isolated from a typical mexican beverage named pulque (cactus juice fermented). Dextrans were purified by precipitation with methanol and dispersed in purified water. This procedure was repeated 3 times to eliminate carbohydrates others than dextra…

Sorption kinetic of aroma compounds by edible bio-based films from marine-by product macromolecules: Effect of relative humidity conditions

International audience; Edible films based on gelatin and chitosan have high gas and aroma barrier properties. This study focused on their capability to sorbed/retain aroma compounds (1-hexanal, 2-hexen-1-ol, 1-hexanol, 3-hexanone and phenol) at three relative humidity level (≤2%, 53% or 84% RH). Whatever the relative humidity condition, the order of sorption is keton (3-hexanone) < aldehyde (1-hexanal) < aliphatic alcohols (2-hexen-1-ol and 1-hexanol) < phenol. This order could be related to the intrinsic chemical properties of aroma compounds. The increase in moisture enhanced the sorption at the highest RH for all the aroma compounds. However, a competition between water and aliphatic al…

Influence of interactions on water and aroma permeabilities of ι-carrageenan–oleic acid–beeswax films used for flavour encapsulation

The objective of this work is to investigate the water and aroma barrier properties of films obtained from ι-carrageenan containing glycerol and lipids mixtures of oleic acid (OA) and beeswax (BW) used for encapsulation of active compounds. Water vapor permeability (WVP) is greatly influenced by lipid composition, encapsulated aroma compound and also relative humidity. WVP decreases when films contain encapsulated aroma compound but increases when the moisture content in the films increases. When oleic acid was the main compound of lipid phase, the plasticizing effect of water revealed through water permeability is less marked. The results of ethyl acetate, ethyl butyrate, ethyl hexanoate, …

Lipid hydrophobicity and physical state effects on the properties of bilayer edible films

Abstract Edible bilayer films based on methylcellulose, used as the film-forming substance, and lipid mixtures, as barriers against moisture transfers, were prepared. The thickness of the lipid layer had little influence on film mechanical properties, regardless of the nature and the solid content of the fat layer. Mechanical resistance was mainly attributed to the methylcellulose matrix. The water vapor transfer rate (WVTR) decreased substantially when film thickness increased up to 100 μm. Upwards, transfer seemed to be independent of thickness. The WVTR was 1.5 up to 2.5 higher for triglyceride lipid layers than alkane lipid layers. Also, WVTR increased by a factor of 25–75 when the liqu…

Lipid-Based Edible Films and Coatings

The quality of food products depends on their organoleptic, nutritional, and microbiological properties, all of which are subject to dynamic changes during storage and distribution. Such changes are mainly due to interactions between foods and their surrounding environment or to migration between different components within a composite food.

Lipids and biopackaging

Packaging is important to preserve food quality. It is a barrier to water vapor, gas, aroma, and solute migration between the food and the environment. With the recent increase in ecological consciousness, research has turned toward finding biodegradable materials. The different kinds of biopackaging are discussed with special focus on edible films. The aim of this review is to focus on the influence of lipids used in edible films, mainly for their efficiency as water-vapor barriers. The structure, degree of saturation, chainlength, physical state, shape and dimension of crystals, and distribution of lipids into the film influence the functional properties of the film. In general, the perfo…

Effect of plasticizers (water and glycerol) on the diffusion of a small molecule in iota-carrageenan biopolymer films for edible coating application.

Translational diffusion of a fluorescein probe has been measured in iota-carrageenan edible films containing different amounts of glycerol (0, 15, 30, and 45%), using fluorescence recovery after photobleaching (FRAP) experiments. The effects of this plasticizer as well as the plasticizing effect of water on the diffusion of fluorescein have been studied in this edible coating mainly composed of natural biopolymer. Diffusion coefficients of about 10(-13) m2 s(-1) have been measured in these films for water activity (aw) lower than 0.7. Above this water content threshold, fluorescein translational diffusion coefficient increases up to 10(-12) m2 s(-1). Another interesting information obtained…

Encapsulation of aroma compounds in biopolymeric emulsion based edible films to control flavour release

Abstract Flavour loss strongly affects food quality. In order to decrease flavour changes during food conservation, different strategies could be used. Aroma compound encapsulation allows the protection of food flavour from loss and degradative reactions, like oxidation. Edible films could be an encapsulation matrix: in the case of emulsified film, lipid globules incorporated can act as carriers of active molecules, such as aroma compounds. Edible films prepared from ι-carrageenans are interesting for good mechanical and gas barrier properties. The aim of this study was to encapsulate different aroma compounds in an ι-carrageenan emulsion based edible film. Release of ten aroma compounds wa…

Wood‐based Packaging

Surface, mechanical and barrier properties of bio-based composite films based on chitosan and whey protein

Mono-component and composite bilayer and blend films composed of chitosan and whey protein were made. Colour, microstructure, water contact angles, swelling, water vapour sorption, barrier properties (oxygen, water vapour), water vapour diffusion coefficients and mechanical properties were determined. The influence of water vapour on barrier properties was studied in relation to the surface and structural properties. Mono-component and bilayer films were transparent with a homogeneous surface. Contrarily, blend films were translucent. Bilayer films had significantly lower water vapour permeability in comparison to mono-component and blend films. In all bilayer films, the air side (chitosan)…

Factors affecting the moisture permeability of lipid-based edible films: a review.

Moisture transfers inside food products could be controlled or limited by the use of edible films. These are usually based on hydrophobic substances such as lipids to improve barrier efficiency. Water permeability of films is affected by many factors, depending on both the nature of barrier components, the film structure (homogeneous, emulsion, multilayer, etc.), crystal type, shape, size and distribution of lipids, and thermodynamics such as temperature, vapor pressure, or the physical state of water in contact to the films. After a brief presentation of lipids and hydrophobic substances used as moisture barrier, cited in the scientific literature, this article reviews all of the parameter…

Edible Arabinoxylan-Based Films. 1. Effects of Lipid Type on Water Vapor Permeability, Film Structure, and Other Physical Characteristics

Arabinoxylans (AX) are natural fibers extracted from maize bran, an industrial byproduct. To promote this polymer as a food ingredient, development of edible coatings and films had been proposed. Indeed, composite arabinoxylan-based films were prepared by emulsifying a fat: palmitic acid, oleic acid, triolein, or a hydrogenated palm oil (OK35). Lipid effects on water vapor permeability (WVP), surface hydrophobicity (contact angles), lipid particle size, and mechanical properties were investigated. Results showed that OK35-AX emulsion films had the lowest WVP. Emulsified films presented a bimodal particle size distribution; however, the smallest particle mean diameter (0.54 microm) was obser…

Effect of oil lamination between plasticized starch layers on film properties

International audience; To reduce the hygroscopic character of biodegradable starch-based films, rapeseed oil was incorporated by lamination (starch-oil-starch 3-layers technique). The lipid lamination followed by starch solution casting step induced an emulsion type structure of dried films. Composite films are more opalescent and glossier than fatty free starch films. For all the films, structure is heterogeneous in the cross-section only. Adding fat induced a twice decrease of the tensile strength. Thermal gravimetry analysis did not show differences between films with and without oil. Lipid reduced the moisture absorption particularly at higher RH as well as the surface swelling index, …

Transfer of volatile phenols at oak wood/wine interface in a model system

Abstract In order to assess the influence of wood on the concentration of aroma compounds during ageing of wine, the transfer of volatile phenols including 4-ethylphenol, eugenol and a homologous series of guaiacols from wine to oak wood were studied in a model system at 10°C. At equilibrium most of the volatile phenols adsorbed in the wood. The results display that the amounts adsorbed depend on the nature of the volatile phenols and the botanical origin of oak wood.

Effects of Candelilla and Carnauba Wax Incorporation on the Functional Properties of Edible Sodium Caseinate Films

International audience; The aim of this study was to evaluate the effects of candelilla (CAN) or carnauba wax (CAR) incorporation on functional properties of edible sodium caseinate (CAS) films. Glycerol and Tween-80 were used as the plasticizer and the emulsifier, respectively. The results showed that the incorporation of waxes increased film opacity, total color differences (∆E), and mechanical resistance and reduced film lightness, water vapor permeability (WVP), and elongation at break. Scanning electron microscopy showed heterogeneous structure of emulsion films with regular distribution of lipid particles. A different internal arrangement was observed as a function of the film composi…

Interface and aroma barrier properties of iota-carrageenan emulsion–based films used for encapsulation of active food compounds

Abstract Food quality preservation requires that the initial properties of the food products be maintained by protecting them from the environment and by limiting the gain or loss of external matter. Barrier edible films can preserve food quality by controlling moisture transfer, oxygen uptake or the loss of volatile aroma compounds. Edible films made of iota-carrageenans display interesting advantages: good mechanical properties, stabilization of emulsions and reduction in oxygen transfer. Moreover, lipid globules incorporated as emulsion-based films can be the carriers for the encapsulation of active volatile molecules such as flavor compounds. Such films also enhance the barrier properti…

Relevance of Interactions between Starch-based Coatings and Plum Fruit Surfaces: A Physical-Chemical Analysis

In order to extend the shelf life of the fruit, improve appearance, and to keep all nutrition properties of the plum from diminishing, edible coatings comprised of wheat starch and wheat starch&ndash

Water vapour permeability, thermal and wetting properties of whey protein isolate based edible films

Abstract This study deals with the effect of whey protein isolate (WPI) and glycerol (GLY) used as a plasticizer on some physical properties of cast whey protein isolate (WPI) films. Films were prepared from heated (80 °C for 30 min) aqueous solutions of WPI at 7, 8, 9 and 10% (w/w), GLY (40%, w/w, of WPI) and WPI at 8% (w/w), GLY (30, 40, and 60%, w/w, of WPI). For all types of films, water vapour permeability for four relative humidity differentials (30–100%, 30–84%, 30–75%, and 30–53%), surface and thermal properties were measured. Varying the proportion of WPI and GLY in edible films had some effect on water vapour permeability, wetting and thermal properties of WPI films. A cumulative …

Modified arabinoxylan-based films. Part B. Grafting of omega-3 fatty acids by oxygen plasma and electron beam irradiation.

Arabinoxylans (AXs) are byproducts of the cereal milling industry. To obtain high-value products, AXs have been used as a film-forming agent. Hence, AX-based films are poor water vapor barriers. The objectives of this study were to graft omega-3 (omega3) fatty acids onto AX polymeric chains by using two new technologies: cold plasma and electron beam (EB) irradiation. Results show that the surface hydrophobicity of the modified films is higher than that of a waxy coating or a low-density polyethylene (LDPE) film. In addition, FTIR spectroscopy analysis reveals vibration bands attributed to new chemical functions. Finally, a decrease in water vapor permeability (WVP) is obtained for the film…

Lipid hydrophobicity, physical state and distribution effects on the properties of emulsion-based edible films

Abstract Addition of lipids to polysaccharide-based films is necessary to improve water vapor barrier properties but it leads to a decrease of mechanical properties. Model emulsified edible films mainly composed of methylcellulose (film-forming substance) and lipid mixtures (moisture barrier) were prepared. The effect of the physicochemical characteristics of the lipid phase (hydrophobicity and physical state) and of its distribution within the methylcellulose-matrix on the mechanical and water vapor barrier film properties was investigated. The nature of the lipid phase had little influence on mechanical properties of emulsified films, but had a substantial effect on the water vapor barrie…

Toward Sustainable PLA-Based Multilayer Complexes with Improved Barrier Properties

Poly(lactic acid) or PLA is currently considered as one of the most promising substitutes of conventional plastics, with low environmental impact, especially for food packaging applications. Nevertheless, some drawbacks, such as high permeability to oxygen, are still limiting its industrial applications. The objective of this study was to highly increase the oxygen barrier performance of PLA without compromising its sustainable nature and following the principles of circular economy perspective. Coproducts coming from mill industries, such as wheat gluten proteins (WG), were used to produce PLA-WG-PLA multilayer complexes with improved barrier performance. Different technologies of industri…

Effect of environmental humidity and coating on aroma transfer through treated papers

Abstract Coupled transfers of aroma compounds and water vapour were investigated by varying the relative humidity gradient of storage (50% or 90%) of two paper packaging at 25 °C. These papers differed in their coating surface: both were identically impregnated then supercalendered, and only one was twice coated on both sides with a synthetic barrier substance. Permeability and solubility coefficients were determined. The coating treatment was more effective to decrease the permeabilities of water vapour and ethyl ester than the effect of RH. On the contrary, the RH modified the water content of the treated papers and affected more strongly their permeability and solubility to cis-3-hexenol…

Spectroscopic analyses of the influence of electron beam irradiation doses on mechanical, transport properties and microstructure of chitosan-fish gelatin blend films

International audience; The objective of this work was to better display the effect of electron beam accelerator doses (0, 20, 40 and 60 kGy) on structural, mechanical and barrier properties of edible lightly plasticized chitosan-fish gelatin blend film. From Electron Spin Resonance (ESR), signal at 3500 G for blend film was identified as free radical formation during irradiation, which might introduce intermolecular cross-linking into the polymer matrix, thus affecting structural properties. Tensile Strength (TS) for gelatin film significantly increased with growing irradiation doses (improved by 30% for 60 kGy), but the TS of chitosan and blend films were not significantly affected. On th…

Characterization of Food Packaging Films with Blackcurrant Fruit Waste as a Source of Antioxidant and Color Sensing Intelligent Material

Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young’s modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by D…

Aroma behaviour during steam cooking within a potato starch-based model matrix.

To help understand the organoleptic qualities of steam cooked foods, the kinetics of aroma release during cooking in a potato starch based model matrix was studied. Behaviour of components having a major impact in potato flavour were studied using solid phase micro extraction-gas chromatography (SPME-GC). Evolution of microstructure of potato starch model-matrix during steam cooking process was analyzed using environmental scanning electron microscopy (ESEM). Both aroma compounds that are naturally present in starch matrix and those that were added were analyzed. Both the aroma compounds naturally presented and those added had different behaviour depending on their physico-chemical properti…

Diffusion of small molecules in edible films: Effect of water and interactions between diffusant and biopolymer

Mass transfers of various molecules in multiphasic food products lead to quality modification and thus require the use of edible films or coatings in-between the foodstuff. Consequently, it is important to assess the barrier properties and efficiencies of edible films as well as to determine the diffusivities of the migrants. Translational diffusion of a reference molecule such as fluorescein, determined by the fluorescence recovery after photobleaching (FRAP) method, displays a threshold of a critical water content inducing an increase of the molecular mobility, and demonstrates that multiple populations of a single molecular specie can be involved in different diffusion kinetics. Further …

FITNESS, première plateforme européenne sur l’emballage et le conditionnement des aliments

National audience; FITNESS (2017-2020) est un projet financé dans le cadre du programme européen Erasmus+. Le but de ce projet est de mettre en place une plateforme virtuelle proposant librement des contenus interactifs (présentations, guides, quizz, webinaires, outils de calcul) en lien avec l’emballage alimentaire et les problématiques de conditionnement des aliments. L’objectif est d’offrir un contenu permettant de comprendre les principes et les enjeux (modules de base), et d’apprendre des techniques plus avancées permettant de maîtriser les impacts ou la sécurité sanitaires des matériaux utilisés (modules avancés). La plateforme s’adresse aussi bien aux étudiants, enseignants et profes…

Sorption of n-hexane in amorphous polystyrene

Sorption properties of pure n-hexane vapor in amorphous polystyrene (PS) were studied at 298 K by thermogravimetry under controlled vapor pressure. Two sorption-desorption cycles were performed by varying the relative pressure between 0 and 0.91. Mixing of PS with n-hexane resulted in a strong plasticization, which was evidenced by quite significant depression in the glass transition temperature of the polymer as shown by differential scanning calorimetry. Maximum quantity of n-hexane sorbed in the PS at 298 K and at a pressure close to saturation was about 12.4 wt %. The thermogravimetry yielded an isotherm with a strong hysteresis loop, explanation of which was hypothesized with the help …

Structure and thermal properties of a chitosan coated polyethylene bilayer film

The thermal and the structural properties of chitosan coated polyethylene (PE) films were studied. The coating process did not significantly influence the thermal stability and the PE surface structure and/or composition of the polyolefin. Dehydration temperature of chitosan films reflected the strength of water/acetic acid/chitosan chains interactions. Glycerol, used as a plasticizer, formed new hydrophilic centres in the film matrix. Moreover it was better integrated in the CSEGLY than in CSAGLY network. Besides, the addition of a plasticizer in the chitosan films decreased the film degradation temperature. There were two main steps for the PE chitosan coated films degradation. The first …

Controlled release of tyrosol and ferulic acid encapsulated in chitosan–gelatin films after electron beam irradiation

Abstract This work deals with the study of the release kinetics of antioxidants (ferulic acid and tyrosol) incorporated into chitosan–gelatin edible films after irradiation processes. The aim was to determine the influence of electron beam irradiation (at 60 kGy) on the retention of antioxidants in the film, their release in water (pH=7) at 25 °C, in relation with the barrier and mechanical properties of biopolymer films. The film preparation process coupled to the irradiation induced a loss of about 20% of tyrosol but did not affect the ferulic acid content. However, 27% of the ferulic acid remained entrapped in the biopolymer network during the release experiments whereas all tyrosol was …

Influence of the physical state of water on the barrier properties of hydrophilic and hydrophobic films.

Water transfer through different films, as a function of the physical state of water in contact with the film, the relative humidity difference, and the water vapor pressure difference, was investigated. The films were two synthetic packagings (hydrophobic polyethylene and hydrophilic cellophane) and an edible film. The physical state of water affects water sensitive films, such as cellophane, inducing a higher liquid water transfer due to interactions with the polymer. For hydrophobic polymers, such as polyethylene, neither the physical state of water nor the relative humidity has an influence on the water permeability. In complex system, such as an edible film composed of hydrophilic part…

Novel functional chitosan and pectin bio-based packaging films with encapsulated Opuntia-ficus indica waste

Abstract The aim of this work was to study the effect of adding red prickly pear, as wasted source of antioxidants on various characteristics of novel functional (antioxidant) chitosan and pectin film formulations. Four types of prickly pear material were used: fruit pulp or peel, as powdered extracts and as aqueous extracts. Prickly pear peel extract was shown to possess higher antioxidant properties than fruit pulp. The antioxidant power of extracts was pretty high, around 1000 mgAAE∙100 g−1 for extract and that of all films around 100 mgAAE∙100 g−1 for films. Even though some changes in thickness, moisture content, water solubility, oxygen permeability and water vapor permeability of fil…

EFFECT OF ULTRASOUND TREATMENT ON PROPERTIES OF GLUTEN-BASED FILM

Abstract Gluten films obtained in acid conditions display some protein dispersion difficulties. Ultrasound treatment (UT) could represent an interesting strategy for improving gluten film appearance. Different UT exposure times were applied to film-forming dispersion. The aim of this work was to investigate the effect of ultrasound treatment on gluten-based films at molecular and mesoscopic levels. Distribution in gliadin and glutenins was determined with SE-HPLC. The UT improved protein dispersion and final film appearance. Sonication did not lead to large changes in various gluten fractions, which suggests absence of important protein breakdown at the molecular level. Gluten showed high t…

Transfer of Water and Active Molecules at the Interfaces in Complex Food Systems: Theoretical and Practical Aspects

Abstract During processing, storage and consumption, mass transfer of various molecules (water, gases, flavour compounds or other solutes) occur between the different phases in complex food products, and/or also between the complex food and its surroundings. These mass transfers can lead to physical and/or chemical changes and thus induce food quality modifications. The objective of this presentation is to better understand the behaviour of small molecules at the interfaces, especially in model heterogeneous food systems. Different techniques have been developed to characterize their properties and their impact on the mass transfers. Particularly, techniques such as rotative diffusion cell …

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…

Edible films and coatings: tomorrow's packagings: a review.

(1998). Edible Films and Coatings: Tomorrow's Packagings: A Review. Critical Reviews in Food Science and Nutrition: Vol. 38, No. 4, pp. 299-313.

Study of the retention and release of n-hexanal incorporated into soy protein isolate–lipid composite films

[EN] This work deals with the study of the kinetic of aroma release, which had been previously incorporated into soy protein isolate (SPI)-lipid composite films. The aim was to determine the influence of type and amount of lipidic material on aroma (n-hexanal) release and retention, as well as the apparent diffusion coefficients. To carry out this study it have been employed SPI-based films containing two SPI:LIPID ratios (1:0.25 and 1:0.5), and two types of lipids, oleic acid (OA) and beeswax (BW), in OA:BW ratios 100:0, 70:30, 50:50, 30:70 and 0:100. The measurements were performed by a gas chromatography technique. The films that showed more retention were SPI:LIPID 1:0.5 100% BW and con…

Wetting properties at the surface of iota-carrageenan-based edible films

International audience; Surface properties of edible films composed of a polymeric matrix of carrageenan in association with hydrophobic material were studied by contact angle measurements. The use of this technique not only in a static mode but also in a dynamic way enables investigation of surface hydrophobicity as well as surface wettability. The absorption flux inside the material can be estimated from the wetting kinetic, which can be very useful to quickly compare water barrier efficiency of the tested films. Comparison of carrageenan films with films containing known amounts of additives enables understanding and correlation of changes of the surface properties with the nature of use…

Water-induced local ordering of chitosan polymer chains in thin layer films

International audience; Carbon-13 NMR (CP-MAS and FSLG 1H–13C HETCOR) have been applied to chitosan salt films synthesized in acetic acid and exposed to different relative humidity environments (32% or 75%) at 20 °C for 1 month. It gives insight in the relationship between structure and functional properties according to the hydration level of this biomaterial as a film. The acetate ions trapped in the chitosan act as structuring agents between chitosan chains for the low hydration state. But, increasing the moisture content induces spontaneous removal of acetic acid and a subsequent modification in the film structure, with an increase in local ordering. HETCOR experiments also showed a mul…

Microstructure and characteristic properties of dogfish skin gelatin gels prepared by freeze/spray-drying methods

International audience; The effects of two pretreatments (microwaves or oven-drying) on the dogfish (Squalus acanthias) skin as well as two drying processes (freeze-drying or spray-drying) on the extracted gelatins were studied. Thus six types of gelatins were obtained, three of which were freeze-dried (FG) and the others were spray-dried (SG), from the untreated skin (US), microwaves-pretreated skin (MS) and oven-pretreated skin (OS). The highest yield (8.67%) was obtained for the OSFG, while the lowest one (3.06%) was measured for the OSSG. Interestingly, all gelatins exhibited relatively high protein (84.02-89.53%), and low lipid (0.50-1.71%) and ash (3.05-7.17%) contents. In addition, g…

Translational diffusion coefficients of volatile compounds in various aqueous solutions at low and subzero temperatures.

International audience; Translational diffusion coefficients (D(12)) of volatile compounds were measured in model media with the profile concentration method. The influence of sample temperature (from 25 to -10 degrees C) was studied on translational diffusion in sucrose or maltodextrin solutions at various concentrations. Results show that diffusivity of volatile compounds in sucrose solutions is controlled by temperature, molecule size, and the viscosity of the liquid phase as expected with the Stokes-Einstein equation; moreover, physicochemical interactions between volatile compounds and the medium are determinant for diffusion estimation. At negative temperature, the winding path induce…

Influence of alginate emulsion-based films structure on its barrier properties and on the protection of microencapsulated aroma compound

In recent years the use of natural polymers coming from renewable sources has greatly increased due to the over-solid packaging waste and dwindling petroleum reserves. Biopolymer films, which contain both lipid and polysaccharide ingredients to form complex packaging enable us to obtain edible films with good mechanical and water barrier properties as emulsified alginate edible films. Moreover, these can be considered to encapsulate active molecules as flavours. The aim of this work is to better understand the influence of the composition and the structure of the film matrix on its barrier properties and thus on its capacity to protect encapsulated active substances. Granulometry, Different…

Effect of Oxidized Potato Starch on the Physicochemical Properties of Soy Protein Isolate-Based Edible Films

The influence of oxidized starch on the physicochemical properties of cast soy protein isolate films is determined in this study. Films were cast from heated (70 °C for 20 min) alkaline (pH=10) aqueous solutions of 7 % soy protein isolate containing 50 % (by mass) glycerol as a plasticizer and different levels of added oxidized starch (0, 5, 10, 15, and 20 %, by mass). For all types of films, opacity, contact angle, tensile strength, elongation at break, water vapour permeability, measured at 25 °C for four relative humidity differentials (30–53, 30–75, 30–84 and 30–100 %), differential scanning calorimetry and microstructure were determined after conditioning film specimens at 25 °C and 30…

Methylcellulose-Based Edible Films and Coatings:  2. Mechanical and Thermal Properties as a Function of Plasticizer Content

Several edible films based on methylcellulose and polyethylene glycol 400 (PEG400) were prepared and stored until equilibration at different relative humidities. Tensile stress−strain curves show very different behaviors as a function of PEG400 and relative humidity. Tensile strength strongly depends on relative humidity and then on water content, more than on PEG400 content. On the contrary, elongation is dependent both on water and PEG400. These differences correspond to the glass transition of the polymer, which affects the elongation more than the tensile strength. However, from DSC measurements, it appears that the PEG400 has no or a very low compatibility with the methylcellulose matr…

Aroma Volatility from Aqueous Sucrose Solutions at Low and Subzero Temperatures

International audience; The gas-liquid partition coefficients of ethyl acetate and ethyl hexanoate have been measured in water and aqueous sucrose solutions from 25 to -10 degrees C by dynamic headspace. Experiments were carried out on sucrose solutions at temperatures where no ice formation was possible. Results showed that when sucrose concentration increased, aroma volatility increased except for ethyl hexanoate and in the highest sucrose concentration solution (57.5%). A quasi-linear temperature decrease on aroma volatility was observed in sucrose solutions from 25 to around 4 and 0 degrees C. Then, from 0 to -10 degrees C, aroma volatility did not decrease: ethyl acetate volatility rem…

Effect of high power ultrasound on physical–chemical properties of polypropylene films aimed for food packaging: structure and surface features

International audience; Biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex) films have been treated with high power ultrasound (HPUS) while submerged in water. Polymer structure and the surface morphology changes were noticed, and obtained results were correlated with the physical properties of tested materials. In anticipation of sonochemically enhanced reactions, physical–chemical profile of film samples was determined using thermogravimetric analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy, UV spectrophotometry and environmental scanning electron mic…

Pla/Protein Complex Films: Multilayer Process and Properties. Matbim 2017

International audience

Water vapour pressure above saturated salt solutions at low temperatures

Abstract The properties of water–salt systems in relation to their vapour pressure are studied especially at low temperature. The water vapour pressure of saturated salt solutions of strontium chloride, zinc chloride, nickel chloride, nickel nitrate, magnesium chloride, magnesium bromide, magnesium nitrate, calcium chloride, potassium nitrite, lithium chloride, lithium bromide, lithium iodide and sodium bromide are measured in a temperature range −40 to +10°C. The apparatus used in this study, is well adapted to measure very low pressure with an uncertainty of pressure measurement of 2% for a range between 10−3 and 10 mm Hg. The experimental values are fitted by Antoine equation with mean p…

Effect of surfactants and drying rate on barrier properties of emulsified edible films

Summary The effects of globule size, nature and concentration of surfactant, and drying duration of water vapour transmission rate and tensile strength of emulsified edible barriers containing methylcellulose and paraffin wax, were measured. of the six surfactants tested, 0.6% purified glycerol monostearate (GMS) produced films with the lowest water vapour transmission rates and the highest mechanical resistance. Longer drying times of film-forming emulsions produced better barrier and mechanical properties. Control of the film forming emulsion stability allowed the reduction of the water vapour transfer rate by an order of magnitude.

Mechanical and barrier properties of extruded film made from sodium and calcium caseinates

Abstract Over the past few years, much interest has been placed into the investigation of increased barrier and mechanical properties of protein films via a multitude of approaches. Generally, these techniques involve modifications of interactions among protein molecules, such as ionic crosslinking using divalent ions. To evaluate the crosslinking effect of Ca 2+ cations, films were made from calcium caseinate (CaCAS) and/or sodium caseinate (NaCAS). The production of caseinate thin films was carried out in two steps: first thermoplastic pellets were made using a co-rotating twin-screw extruder, then they were transformed into thin films (60 μm) using a classical film blowing machine. Tensi…

Liquid and vapour water transfer through whey protein/lipid emulsion films

BACKGROUND: Edible films and coatings based on protein/lipid combinations are among the new products being developed in order to reduce the use of plastic packaging polymers for food applications. This study was conducted to determine the effect of rapeseed oil on selected physicochemical properties of cast whey protein films. RESULTS: Films were cast from heated (80 °C for 30 min) aqueous solutions of whey protein isolate (WPI, 100 g kg−1 of water) containing glycerol (50 g kg−1 of WPI) as a plasticiser and different levels of added rapeseed oil (0, 1, 2, 3 and 4% w/w of WPI). Measurements of film microstructure, laser light-scattering granulometry, differential scanning calorimetry, wetti…

Design of Gelatin Pouches for the Preservation of Flaxseed Oil during Storage

Flaxseed oil (FO) is composed mainly of polyunsaturated fatty acids that are very sensitive to oxidation induced by oxygen, temperature, and light. To overcome this problem, gelatin-based films containing glucose are crosslinked via the Maillard reaction (MR) at 120 &deg

The Schroeder paradox or how the state of water affects the moisture transfer through edible films

The objective of this work was to better understand the water permeation through edible films when water is either in its vapour or in its liquid state related to their physico-chemical properties. Film based on iota-carrageenans or sodium alginate, containing or not fat, and encapsulating or not an aroma compound (n-hexanal) have been prepared. Films were conditioned at three different relative humidities, 0%, 43% and 84%. The incorporation of the n-hexanal in both types of biopolymer modifies the mechanical properties of film matrix and has a synergistic effect when associated to fat. Increasing the moisture content induces film plasticization by decreasing the glass transition of the gly…

Enhancement of structural, functional and antioxidant properties of fish gelatin films using Maillard reactions

International audience; This study investigates the effect of Maillard reactions (MR) on the physico-chemical and biological properties of fish gelatin based edible films. Glucose was incorporated in gelatin film forming solutions at different glucose/lysine molar ratios: 0.5/1.0, 1.0/1.0 and 5.0/1.0. The MR was then induced by heating films at 90 °C for 24 h in dry conditions. Color changes and browning index measurements were used to pursue the MR kinetic. Results showed that the development of MR products was dependent on the glucose content and on the reaction time. Mechanical and thermal properties of treated films displayed an increase in tensile strength, elongation at break and glas…

Beyond Biodegradability of Poly(lactic acid): Physical and Chemical Stability in Humid Environments

International audience; Poly(lactic acid) (PLA) is the most traded biodegradable and biobased material. It is largely used as ecofriendly substitute of conventional plastics. Nevertheless, one of the main limiting factors is its water sensitivity. PLA reacts with water and is hydrolyzed during time, which determines its performance. Limited information related to the hydrolysis mechanism driven by water in vapor state is available in scientific literature. Literature is mainly focused on the effects of water in liquid state. This lack of information is of significant importance, since PLA interacts with water in both phases. This work was aimed to give a full depiction of the chemical and p…

Influence of thermal process on structure and functional properties of emulsion-based edible films

Abstract Synthetic food packaging is classically used to prevent mass transfer of various small molecules (water, gases, flavour compounds or solutes) between a food and its surrounding medium. In the case of composite foods, the development of edible films and coatings, applied between the different phases of this food is rising up. The increase of such food products shelf-life is indeed related to the barrier efficiency of these edible packaging against small molecules transfers. This is especially true for water transfer between compartments of different water activities in the same food, that leads to important physico-chemical changes and therefore to food quality deterioration. Film-f…

Influence of high power ultrasound on physical-chemical properties of polypropylene films aimed for food packaging: barrier and contact angle features

Investigation was focused on the impact of high power ultrasound (HPUS), also called thermosonication, on the oxygen permeation properties (permeability, solubility and diffusion coefficients) of barrier films aimed for food packaging. For this purpose, biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex) were used. The physical–chemical profile of the samples was determined using goniometry. There is a significant impact only of extreme HPUS conditions (the longest time and the highest amplitude) on the permeability, solubility and diffusion coefficients of oxygen through the BOPP films. …

Wine Oxidation and the Role of Cork

The present review aims to show the state of the art of oxidation mechanisms occurring especially in white wines by taking into account knowledge from different fields in relation to the subject. It is therefore divided into three main parts. First, the mechanisms of oxidation relevant to white wine are discussed in the light of recent scientific literature. Next, the phenomenon of oxygen solubility in wine during the winemaking process, and in particular during bottling is stated theoretically as well as practically. Finally, the aspect of wine conservation after bottling is examined with respect to mass transfers which may occur through the closure, with a special emphasis on cork. Curren…

Barrier properties of chitosan coated polyethylene

The transfer properties of chitosan coated polyethylene (PE) films were studied. The barrier properties of non coated PE were not affected by relative humidity changes. The presence of the hydrophilic chitosan layer acted as a water reservoir on the polyethylene film surface which significantly promoted its sensitivity to the water vapour. The water vapour permeability increased 1.85 times at a higher RH. Coated PE films showed more than two-order decrease in the oxygen permeability (PO2) and three-order-decrease in the carbon dioxide permeability (PCO2). When the chitosan coated PE surface was exposed to the water vapour, the PO2 and the PCO2 were significantly increased. However, the perm…

Impact of electron beam irradiation on fish gelatin film properties

International audience; The objective of this work was to display the effect of electron beam accelerator doses on properties of plasticized fish gelatin film. Electron spin resonance indicates free radical formation during irradiation, which might induce intermolecular cross-linking. Tensile strength for gelatin film significantly increases after irradiation (improved by 30% for 60 kGy). The vapour permeability is weakly affected by irradiation. Surface tension and its polar component increase significantly and are in accordance with the increase of wettability. So, irradiation may change the orientation of polar groups of gelatin at the film surface and crosslink the hydrophobic amino aci…

Interactions between aroma and edible films. 1. Permeability Of methylcellulose and low-density polyethylene films to methyl ketones.

This work contributes to the study of aroma transfers through edible and plastic packaging films. Permeability, sorption, and diffusivity of three methyl ketones (2-heptanone, 2-octanone, and 2-nonanone) in and through low-density polyethylene and methylcellulose-based edible films have been determined. Permeability was measured using a dynamic method coupled with a gas chromatograph. The methyl ketone permeability of polyethylene films mainly depends on diffusivity of the penetrant in the polymer. In the case of 2-heptanone, a saturation of the polymer network is observed at high vapor concentrations. The formation of clusters could take place when concentrations are higher in the vapor ph…

Coupling tyrosol, quercetin or ferulic acid and electron beam irradiation to cross-link chitosan–gelatin films: A structure–function approach

International audience; Marine industry by-products, chitosan and fish gelatin, entrapping natural antioxidants (ferulic acid, quercetin and tyrosol) were used to prepare edible active films by casting. The films were composed of chitosan and fish gelatin (1:1 w:w) and incorporating antioxidants (∼50 mg/g). After solvent evaporation (drying), the films were irradiated at 60 kGy by electron beam. This treatment aims at investigating the coupled effect of irradiation with the presence of active compound on the structure and functional properties of the films. Electron Spin Resonance (ESR) unravelled free radical formation during irradiation in films containing ferulic acid or tyrosol which fa…

Barrier, structural and mechanical properties of bovine gelatin-chitosan blend films related to biopolymer interactions

BACKGROUND The increased use of synthetic packaging films has led to a high ecological problem due to their total non-biodegradability. Thus, there is a vital need to develop renewable and environmentally friendly bio-based polymeric materials. Films and coatings made from polysaccharide polymers, particularly chitosans and gelatins have good gas barrier properties and are envisaged more and more for applications in the biomedical and food fields, as well as for packaging. In this study a casting method was used to develop an edible plasticised film from chitosan and gelatin. Aiming to develop a blend film with enhanced properties, the effects of mixing chitosan (CS) and gelatin (G) in diff…

Active biopackaging produced from by‐products and waste from food and marine industries

The agro‐food industry cannot today do without packaging to preserve and above all market its products. Plastic materials coming mainly from petrochemicals have taken a predominant place in the food packaging sector. They have become indispensable in many sectors, from fresh to frozen products, from meat and dairy products to fruit and vegetables or almost‐ready meals. Plastics are cheap, their lightness reduces transport costs, and their convenience is fundamental for out‐of‐home catering. However, plastics pose serious end‐of‐life issues. The development of materials that are more respectful of the consumer and the environment has become a major issue. In addition, the agro‐food industrie…