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This data article contains values of oxygen and carbon dioxide solubility and diffusivity measured in various model and real food products. These data are stored in a public repository structured by ontology. These data can be retrieved through the @Web tool, a user-friendly interface to capitalise and query data. The @Web tool is accessible online at http://pfl.grignon.inra.fr/atWeb/. Keywords: Diffusivity, Solubility, Data, Data warehouse, Ontology, Food, O2, CO2

International audience; Despite CO2 production and diffusion during ripening of semi-hard Swiss-type cheese are considered as important quality parameters, the research concerning key gas production and transfer in cheese remains widely overlooked. In this study, experimentally assessed CO2 production was coupled with transfer coefficients in a mathematical model in order to predict CO2 gradients formed inside the cheese during ripening. The permeability coefficient of CO2 through the multilayer barrier packaging which wraps the cheese during ripening was also included in the model. The presented model was validated by assessing the CO2 concentration in the cheese and its partial pressure in the packaging headspace. CO2 production rate was found to be the most important input parameter affecting CO2 gradients formed in cheese during ripening whereas the other input parameters (solubility, diffusivity, permeability) had little effect on the total CO2 gradient.

Modified atmosphere packaging (MAP) is commonly used for packing fruits and relies on the natural interplay between the produce physiology (consumption or production of gases and vapours) and the mass transfer properties of the packaging material (gases and vapours permeation values), with possible gas flushing, in order to reach optimal conditions of storage. Then success of MAP depends on the choice of the material, whose mass transfer properties must match produce requirements. Decision aid tool for MAP of fruits would aim at helping decision makers to find the best material for a given fruit, but are not yet well developed and commonly used. If virtual MAP models exist, their objective is to dimension gas permeabilities of the packaging material to the needs of the fruit. They do not take into account multi-criteria design such as cost and mechanical properties. Then, this chapter brings an overview on current researches and developments in the field of biological, material, and computing science that could lead to the development of such a tool in regard to constitution of databases, and reliability of optimization and interrogation procedures.

Coupling gas transfer with predictive microbiology is essential to rationally design modified atmosphere packaging (MAP) strategies to ensure and guarantee food safety. Nowadays, these strategies are generally empirically built and over-sized since packaging material with high barrier properties is often chosen by default even if such a high level of protection is not systematically required. Protection strategies could be improved using rational sizing based on quantitative analysis and mathematical modeling of mass transfer. This paper aims at reviewing the current knowledge available for developing such a tool and the further research needed. First there is a special focus on oxygen (O2 ) and carbon dioxide (CO2 ) solubility and diffusivity parameters, which are absolutely indispensable to accurately model mass transfer in MAP systems. Next, the current knowledge of the effect of O2 /CO2 on the growth of microorganisms is explored with an emphasis on predictive microbiology. The last part points out the main bottlenecks and further research needed to be carried out in order to develop an efficient MAP modeling tool for food safety coupling O2 /CO2 transfer and predictive microbiology.

A mathematical model describing the water content-dependent release of an antimicrobial agent (allyl isothiocyanate (AITC)) from a bio-based film to the packaging headspace was implemented. The system was characterised experimentally by assessing release kinetics and diffusivities. The model was validated by comparing simulations to experimental data. In spite of the high complexity of the system coupling moisture and antimicrobial diffusion within the packaging material and then release into headspace, the presented model provides a good enough reproduction of experimental conditions. A sensitivity study conducted on the model showed that the release kinetics of the antimicrobial agent were the most influential parameters, and that the diffusivity of moisture and AITC within the film have negligible impact. The model was then used to demonstrate the efficiency of such packaging for shelf-life optimization as it successfully inhibited the growth of bacteria. This work provides a framework that can be used for decision support systems. Industrial relevance This work is relevant to industrial considerations as it provides a framework for decision support systems to help manufacturers and researchers to tailor their active packaging. Indeed, the development of anti-microbial applications for food packaging is a time-consuming task, that, if undertaken from a sole experimental point of view, can also be expensive. The use of the simulation framework proposed (that was experimentally validated) helps investigate and compare multiple packaging configurations. Numerical simulation are made by changing the kinetics of release parameters and initial anti-microbial content within the packaging without requiring further experiments, the main issue lying on having plausible values for the parameters.

The use of wheat gluten as sensing material to detect carbon dioxide is a promising approach. The dielectric properties of wheat gluten are modified in contact with carbon dioxide gas at high relative humidity (90%) and at a temperature of 25 °C due to a structural change in the sensing material, where amino groups act as receptors to carbon dioxide molecules. In the present study, the effects of carbon dioxide on the electrical and dielectric properties of wheat gluten at 20% and 90% of relative humidity (usually found in food packaging) are determined and discussed. At 90% of relative humidity, a linear increase of the dielectric permittivity and dielectric loss was observed with a significant hysteresis which increased with the number of carbon dioxide treatment cycles. One of the significant results is the increase in the dielectric permittivity from 7.01 ± 0.07 to 12.02 ± 0.03 with a sensitivity of 31.38 ± 0.06 fF/%CO2 measured at 868 MHz. The developed sensor is sought to be integrated in the design of UHF-RFID (ultra-high frequency − radio frequency identification) systems working at 868 MHz.

Oxygen and carbon dioxide solubility and diffusivity are 2 key parameters to understand gas transfer in food matrices. Knowledge of these parameters could help to predict gas concentration in modified atmosphere packaging and, consequently, to predict shelf-life of the product through the development of appropriate mathematical models. The aim of this review is to present the existing methodologies to quantify O2 and CO2 contents in food, especially in solid food matrices which is very challenging. There is a focus on how these methodologies could be used to determine gas transfers kinetics. Data of O2/CO2 solubilities and diffusivities in food are collected and compared with a specific emphasis on the food characteristics and factors impacting them. An analysis of the current state of knowledge in solid food matrices is carried out to tentatively build a general predictive model of the O2 and CO2 solubility and diffusivity extendable to any kind of food matrix.

International audience; This study focuses on CO2 diffusivity, which is one of the most important factors impacting eye growth in semi-hard cheese, but yet has scarcely been investigated in literature. The effect of compositional and ripening parameters on experimental CO2 diffusivity in semi-hard cheese was studied. CO2 diffusivity in semi-hard cheese showed a complex relationship with temperature in the range 4 to 25 °C, represented by a quadratic curve with the highest diffusivity at 13 °C. Salt was found to impact CO2 diffusivity, with a decrease of about 60% for 0 to 2.7% w/w salt addition, which may be ascribed to viscosity increase of the cheese matrix and “salting in” effect of protein. CO2 diffusivity was found to increase with moisture content from 39 to 42% w/w, then it decreased from 42 to 48% w/w. Inevitable changes in protein content of the three cheese variants may be responsible for the complex behaviour observed.

Despite the fact that CO2 production by Propionic Acid Bacteria (PAB) fermentation is the driving force for eye growth in most hard and semi-hard cheese types, few coefficients of CO2 production have been assessed in literature. In this study, the diffusion free CO2 production rate coefficient was experimentally assessed in semi-hard cheese as a function of salt content (0-1.3% w/w), ripening temperature (13-25 degrees C) and ripening time (2 weeks). The CO2 production rate decreased linearly with increasing salt content due to the inhibition effects of salt on the PAB, while it increased with temperature, due to the vicinity with the Poptimum growth temperature (25-30 degrees C). A lower rate of production was observed in the first days of ripening, followed by an increase in CO2 production rate and consequent decrease due to the lower availability of the main substrate (lactate). We proposed a polynomial equation for predicting changes in the CO2 production rate during ripening. This equation may be used to better describe the phenomenon of eye growth occurring in cheese with propionic acid fermentation.

Assessing gas permeation of the whole food packaging in industrial conditions (RH, temperature including stretching and sealing effect) is fundamental for predicting the quality changes of packed food during processing and shelf life. Permeability coefficients are usually assessed on a small flat, piece of packaging material which is not representative of the whole pack (usually assembly of tray + lid film or pouches of flexible films sealed on at least 2 or 3 sides) used in the industry. Moreover, conditions used are standardised (temperature of 23 °C, 0%RH) which are not representative of conditions that prevail in real use. This simplified approach may lead to erroneous mass transfer predictions when simplified permeability values are used in calculation. To face this problem, we propose a simple methodology for the assessment of the gas permeability coefficients (N2, CO2, O2) in sealed intact large scale (industrial) packaging (whole packaging) in conditions of temp and RH mimicking the real conditions of use (encountered by the material in contact with the food product). The CO2 permeability assessed in the industrial-like conditions was significantly higher compared to the one assessed with standard method. The higher gas permeation measured was ascribed to the impact of industrial operations such as shrinking and hot sealing. Our results highlight the necessity to better characterize impacts of industrial conditions such as hot sealing and shrinking on the permeability of the whole pack when prediction of gas permeation through packaging during food processing is needed.

Despite CO2 being one of the most important gases affecting the quality of most semi-hard cheeses, the thermodynamic properties of this molecule in relation to cheese ripening have rarely been investigated. In this study the CO2 solubility coefficient was experimentally assessed in semi-hard cheese as a function of the most relevant compositional and ripening variables. As expected, CO2 solubility was found to linearly decrease with temperature in the range 2–25 °C. Unexpectedly, solubility was not significantly different at 39% and 48% moisture, while it was found lower at 42%. Unavoidable changes in protein content of the three cheese variants is suspected to produce an interaction with water content, leading to complex interpretation of the results. Increasing salt content in cheese from 0 to 2.7% w/w significantly decreased CO2 solubility by about 25%, probably due to the increased bonded water molecules in the cheese water phase.

Based on the measurement of local oxygen partial pressure kinetic, a non-invasive methodology was proposed to assess O2 diffusivity ( D O 2 ) in liquid, viscous and solid matrices. This new method was compared with a previous invasive method, developed by the same group, based on the same principle. The new method has proven to be essential to measure D O 2 in solid food matrices where invasive methods usually failed. It was successfully used to obtain D O 2 of cooked ham and processed cheese which were found respectively equal to 0.450 ± 0.004 × 10−9 m2·s−1 and 1.15 ± 0.11 × 10−9 m2·s−1 at 20 °C. D O 2 was also evaluated as a function of temperature (from 5 to 30 °C) and viscosity in lipid-based matrices. These results have permitted to determine activation energy of the diffusion and have revealed that increasing viscosity of the lipid matrices tested did not impact their D O 2 values.

The main objective of the present work was to determine whether a single agropolymer [wheat gluten (WG)] could fit the modified atmosphere packaging (MAP) requirements of a range of six different fresh produce in key terms of oxygen permeation (PeO2) and CO2/O2 permselectivity (S) values. The required properties for optimal packaging of fresh fruits and vegetables were first evaluated using the Tailorpack MAP modelling software (UMR IATE, Montpellier, France) with packaging dimensions and respiratory and optimal atmosphere data as input parameters. Then, the modelled values obtained were compared with the properties of a range of WG composite films: monolayer self-supported or multilayer at microscale or nanoscale, cast or thermoplasticised, with different formulations (percentage of plasticisers or nanofillers). The experimental gas transfer properties that could be covered by these materials ranged from 0.05 × 10−10 to 2.00 × 10−10 mol/m2 s Pa for PeO2 and up to 18.0 for S. These ranges are much larger than conventional plastics that exhibit PeO2 from 0.10 × 10−10 to 0.20 × 10−10 mol/m2 s Pa and S up to 4.5. It was demonstrated from a food-requirements-driven (Tailorpack modelling) and a multiscale film structuring (WG-based composites) approaches, that transfer properties of WG-based films would fit the requirements of the six selected fruits and vegetables better than conventional plastics. Copyright © 2012 John Wiley & Sons, Ltd.

E-mail address: c-guillaume@univ-montp2.fr; International audience; The objective of the present work was to understand how the structural, surface, water vapour and gas barrier properties of wheat gluten (WG) coated paper could be influenced by the features of paper. For this purpose, a surface treated paper (TP) and an untreated paper (UTP) were compared. Penetration of WG-coating into the bulk of paper was more pronounced in UTP than TP. This led to the formation of a significant junction zone resulting in an interpenetrated structure for WG–UTP, suggesting a composite- like structure, while a bi-layer one was obtained for WG–TP. Differences in WG penetration were related to the hydrophilicity, roughness and porosity of the paper used. Even though the extent of penetration did not greatly affect the surface properties (water and oil resistance), the transfer properties (water vapour, O2 and CO2) of WG-coated papers were significantly improved when WG-coating highly penetrated: while the WG–TP behaved as a micro-perforated material, the WG–UTP behaved as WG-film

A mechanistic model coupling O-2 and CO2 mass transfer (namely diffusion and solubilisation in the food itself and permeation through the packaging material) to microbial growth models was developed aiming at predicting the shelf life of modified atmosphere packaging (MAP) systems. It was experimentally validated on a non-respiring food by investigating concomitantly the O-2/CO2 partial pressure in packaging headspace and the growth of Listeria monocytogenes (average microbial count) within the food sample. A sensitivity analysis has revealed that the reliability of the prediction by this "super-parametrized" model (no less than 47 parameters were required for running one simulation) was strongly dependent on the accuracy of the microbial input parameters. Once validated, this model was used to decipher the role of O-2/CO2 mass transfer on microbial growth and as a MAP design tool: an example of MAP dimensioning was provided in this paper as a proof of concept. (C) 2015 Elsevier Ltd. All rights reserved.

Composite materials made from fibrous support coated with agro-polymers are widely commercialized for different appli- cations. But, their transfer properties have only been sparingly studied despite their importance in membrane technologies or food packaging. Furthermore, most of past studies on the topic have been focused on the impact of surface properties of the support on the final coated material structure and its properties; leaving unexplored the potential impact of the in-bulk structure of the support. This study demonstrated the influence of in-bulk structure and especially fibers refining degree of 4 kraft papers (SP28, 36, 60, and 80) on the structure, and surface and gas transfer properties of their respective wheat gluten (WG) coated papers (WGP28, 36, 60, and 80). Paper presenting a high fibers refining degree (SP28) exhibited very tight and narrow in bulk fibers network which pre- vented most of the WG-coated layer penetration, maintaining an important WG apparent layer on top of the paper and a small fibers/wheat gluten composite zone inside (WGP28). Such structure gave strong "WG-like" properties to the final coated material with moderate oxygen permeation and high permselectivity (1.50 3 10 211 mol m 22 s 21 Pa 21 and 8.09, respectively for WGP28) whereas the highly impregnated structure of coated papers built on lowly refined papers (SP80, with wide and loose structure) gave coated materials presenting weak "WG-like" properties, supposedly due to a thick composite zone presenting interfacial defects, with higher oxygen permeation and very limited permselectivity (11.90 3 10 211 mol m 22 s 21 Pa 21 and 1.06, respectively for WGP80). V C 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2848-2858, 2013

Gas transfer properties of wheat gluten (WG) coated paper and their ability to fulfil the requirements in eMAP of fresh parsley were studied. Permeation of gases through WG-paper was demonstrated to be RH-dependent and closely related to structural modification in the WG layer. Formation of micro-cracks was evidenced in dry conditions; but when increasing RH, plasticisation occurs within the protein layer and micro-fractures were reduced until disappearance. This reversible phenomenon allowed the WG-layer to recover its integrity at RH higher than 70%, and the WG character to be expressed in such conditions. When used at 20 degrees C and 80% RH as part of the packaging of parsley, modified atmosphere was created and a steady state of 11 kPa O-2 and 4.5 kPa CO2 was reached after 45 h. In such conditions, the overall quality of parsley leaves remained acceptable during 8 days, with only 28% loss of chlorophyll. (C) 2013 Elsevier Ltd. All rights reserved.

International audience; To overcome the limitations of current trial and error approaches used to design food packaging, a requirement driven approach was adapted from the software and service industries to the field of fresh fruits and vegetable packaging. Based on 5 steps, it relies on the knowledge of produce needs and the use of modeling tools to turn produce requirements into packaging properties before designing the packaging. It was then successfully applied to dimension and design an active packaging, tailor made for optimal preservation of strawberries at 20 degrees C. The solution consisted in a PET punnet providing protection against physical damage and a lid ensuring both gas transfer for optimal atmosphere and release of an active agent acting against mold growth. This active lid was made of wheat gluten proteins containing 2-nonanone that was quickly released only in high RH conditions in an amount equal to the minimal inhibition dose for Botrytis cinerea. Industrial Relevance: Design of packaging for fresh produce such as fruits and vegetables is still mainly based on a trial and error approach (often referred as "pack and pray") that does not ensure conception of an optimal packaging for produce preservation. The non-optimal character of existing packaging is one of the main causes of fresh fruit and vegetable losses along the supply chain. This study proposes an alternative approach to design optimal packaging for fresh and respiring produce: the requirement driven approach. This approach was adapted from the field of software and service industries to the specificity of fresh produce packaging one. It takes into account the needs of the produce (e.g. physical protection, microbial protection or optimal atmosphere for preservation) from the very beginning of the conception process to reduce the risks of inadequacy between the packaging and the produce. In addition to knowledge of the produce physiology and needs, this approach relies on the use of modeling tools to turn produce requirements into packaging properties before designing the packaging. The efficiency of such method was demonstrated through a case study on strawberry packaging. Given the increasing quantity of data available on produce physiology and needs, and the online, free to use and user friendly character of recent MAP modeling tools such as Tailorpack (www.tailorpack.com), generalization of the requirement driven approach proposed in this study could be of major interest for the fresh fruits and vegetable packaging industry. It should help to design optimal packaging for specific produce and thus reduce risk of losses along the supply chain by improving preservation.

IATE Axe 5 : Application intégrée de la connaissance, de l’information et des technologies permettant d’accroître la qualité et la sécurité des aliments Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; Mathematical models are instrumental tools to predict gas (O2 and CO2) evolution in headspaces of Modified Atmosphere Packaging (MAP). Such models simplify the package design steps as they allow engineers to estimate the optimal values of packaging permeability for maintaining the quality and safety of the packed food. However, these models typically require specifying several input parameter values (such as maximal respiration rates) that are obtained from experimental data and are characterized by high uncertainties due to biological variation. Although treating and modelling this uncertainty is essential to ensure the robustness of designed MAPs, this subject has seldom been considered in the literature. In this work, we describe an optimisation system based on a MAP mathematical model that determines optimal permeabilities of packaging, given certain food parameters. To integrate uncertainties in the model while keeping the optimisation computational burden relatively low, we propose to use an approach based on interval analysis rather than the more classical probabilistic approach. The approach has two advantages: it makes a minimal amount of unverified assumption concerning uncertainties, and it requires only a few evaluations of the model. The results of these uncertainty studies are optimal values of permeabilities described by fuzzy sets. This approach was conducted on three case studies: chicory, mushrooms and blueberry. Sensitivity analysis on input parameters in the model MAP was also performed in order to point out that parameter influences are dependent on the considered fruit or vegetable. A comparison of the interval analysis methodology with the probabilistic one (known as Monte Carlo) was then performed and discussed.

International audience; This chapter discusses the use of wheat gluten (WG) based materials for food packaging. It presents the two technological processes to prepare WG-based materials and reviews the ways to modulate mechanical and mass transfer properties, with a specific section devoted to WG-based nanocomposites. The chapter also includes a case study of using WG-based materials (paper coated by wheat gluten) as modified atmosphere packaging for fruits and vegetables.

Correspondance: fax: +33 4 6714 4990. E-mail address: c-guillaume@univ-montp2.fr Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; Quality changes of fresh endives were related to packaging condition and development of the internal atmosphere composition. Three packaging conditions were tested at 20C: a macroperforated oriented polypropylene (OPP) pouch considered as "unmodified atmosphere packaging" (UAP) and a low density polyethylene (LDPE) pouch with or without an individual oxygen scavenger sachet to create active or passive modified atmosphere packaging (MAP), respectively. With a steady modified atmosphere composed of 3 and 4.5 kPa of O2 and CO2, respectively, the effect of passive MAP on colour changes in endives was similar to that of UAP. Benefit of MAP of endives was obtained by using an O2 scavenger, i.e. active MAP, that did not change O2 and CO2 partial pressure during the steady state period, compared to passive MAP, but induced a 50% reduction of the transient period. This reduction led to an important delay in greening and browning of endives

International audience; In response to consumer demand and the market trend for more convenient, safer products that can be stored longer despite containing low quantities of preservatives, active packaging has become more of a factor in food packaging innovations. Packaging that was limited to protecting food products against external influences is no longer considered as an inert barrier and might be termed active when it interacts with food, or its surrounding environment, to delay degradation and extend shelf-life. Currently, there is an increasing interest in the possible use of natural solutions to delay and prevent microbial growth in food items, responding to consumer pressure to reduce chemical additives in foods and/or strong, detrimental thermal treatment. Antimicrobial packaging is expected to improve the shelf-life and microbial quality of packaged food. The antimicrobial effect of packaging materials could be achieved either by direct contact with food surfaces, using antimicrobial, non-migratory, or controlled diffusion systems, or by indirect contact, using volatile antimicrobial-releasing systems to create a modified antimicrobial atmosphere in the headspace of packaging. Many preservatives, such as bacteriocins, organic acids, various plant extracts, volatiles from essential oils, and silver-substituted zeolite, have been incorporated in packaging materials to provide antimicrobial activity.

The ability of an original pH-reversible treatment of milk to improve rennet gelation was evaluated by rheological measurements on reconstituted skim milk supplemented or not with casein. Samples were acidified at 4°C to pH 5.10 by injection of CO 2 in a laboratory pilot plant (pressure less than 2 MPa) and then depressurised under vacuum. Depressurisation induced the pH to return to its initial value (6.65±0.02) and restored the mineral and protein partition of milk as well as the water solvation, the size diameter and the zeta potential of the casein micelles. After rennet addition, CO 2 -treated milk showed a decrease of the rennet clotting time and an increase of the firming rate compared with a non-treated sample. Moreover, this treatment had a positive effect on the release of glycomacropeptide during enzymatic gelation, suggesting that the rennet accessibility of κ -casein was greater in the CO 2 -treated than in the non-treated sample. The pH-reversible CO 2 acidification greatly activated the rennet gelation of casein-supplemented milk. Indeed, without this treatment, no clotting was observed even 300 min after rennet addition. Therefore, this CO 2 treatment might involve modification of the micellar surface properties in favour of rennet gelation.

An experimental method based on the controlled chymosin-induced kappa-casein hydrolysis of milk was proposed to modify micellar reactivity. Milk samples with a degree of kappa-casein hydrolysis of 19, 35, and 51% were obtained. The physicochemical properties of partially converted casein micelles were determined. The net negative charge of casein micelles was reduced with increasing degree of kappa-casein hydrolysis and a small but significant decrease in hydrodynamic diameter and micellar hydration were noted. Dynamic low amplitude oscillatory rheology was used to monitor the rheological properties of acid milk gels (GDL) made with partially chymosin-hydrolyzed milks in comparison with those of strictly acid and rennet gels. An increase in the gelation pH value was observed with increasing the degree of kappa-casein hydrolysis. The moduli values (G' and G'') reached 2 h after the point of gel were, for all degrees of hydrolysis tested, significantly higher than those of strictly rennet and acid gels. Comparison of changes in delta G'/delta t with time indicated differences in gel formation that could be related to the increased values of G' obtained for acid gel made with chymosin-treated milk. At a given time after gelation (2 h), increasing the degree of kappa-casein hydrolysis in milk led also to an increase in the loss tangent and the serum holding capacity of acid milk gels suggesting a correlation between these two parameters.