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Author: Pant, Astrid ×

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Now showing 1 - 10 of 20
  • Publication
    Application of humidity absorbing trays to fresh produce packaging
    ( 2019)
    Jalali, Ali
    ;
    Rux, Guido
    ;
    Linke, Manfred
    ;
    Geyer, Martin
    ;
    Pant, Astrid
    ;
    Saengerlaub, Sven
    ;
    Mahajan, Pramod
    Humidity control is one of the biggest challenges in modified atmosphere and humidity packaging (MAHP) of fresh horticultural products, especially those of high transpiration rate. Humidity absorbing trays containing active moisture absorber substance in the structure have been recently emerged as a potential solution in this area. Here packaging of strawberries using two different humidity absorbing trays of different moisture absorption capacity named T0 and T12, under fluctuating ambient conditions was simulated using an integrated mathematical modeling approach and validated experimentally. The model considered transpiration and respiration behavior of fresh produce, moisture absorption by packaging tray, gas and water vapor permeation through the perforated packaging film to predict changes in relative humidity of packaging headspace as well as moisture condensation within the package. Based on RMSE values, there was a good agreement between predicted and measured data of humidity, moisture loss, absorption and condensation inside the package. The RMSE values for prediction of the headspace humidity were 1.28, 2.38 and 4.34 and corresponding R2 values were 0.71, 0.86 and 0.87 for control, T0 and T12 packages, respectively. Further simulations were made to design MAHP for strawberry using T12 tray and appropriate number of perforations in packaging film under different conditions of fruit mass and ambient temperature. For example, using 1 perforation of 0.8 mm diameter for 6 days storage of a 400 g strawberry package under 15 °C ambient temperature, resulted in desired gas composition of O2 (7.0%) and CO2 (12.6%), while preventing humidity saturation and consequent moisture condensation by keeping in-package equilibrium humidity at 97.6% and maintaining fruit mass loss less than 0.3%.
  • Publication
    Effect of temperature and relative humidity on the reaction kinetics of an oxygen scavenger based on gallic acid
    ( 2018)
    Pant, Astrid
    ;
    Dorn, Julia
    ;
    Reinelt, Matthias
    Gallic acid (GA) is a potential oxygen scavenger for food packaging applications. In this study we investigated the effect of temperature and relative humidity (RH) on the reaction kinetics of an oxygen scavenger consisting of GA and sodium carbonate. The reaction was described by a second-order kinetic law and the reaction rate coefficient k as well as the scavenger capacity n were determined from experimental data using a multiple-run downhill simplex method. Both the rate coefficient and the scavenger capacity increased significantly with higher temperatures. At 21°C it was shown that both the rate coefficient and the scavenger capacity increased significantly with higher RH. However, below 54% RH, there was no detectable reaction. For optimum scavenger performance we therefore recommend GA-based scavengers for packaging of food products with a high water activity stored at room temperature. Prior to application, the packaging materials with GA-based scavengers can be stored at 21°C and 54% RH without losing their scavenger activity. The results of this study provide the basis for the functional design of active packaging systems with GA-based oxygen scavengers.
  • Publication
    Functional properties of foamed and/or stretched polypropylene-films containing sodium chloride particles for humidity regulation
    ( 2018)
    Sängerlaub, Sven
    ;
    Seibel, Karoline
    ;
    Miesbauer, Oliver
    ;
    Pant, Astrid
    ;
    Kiese, Sandra
    ;
    Rodler, Norbert
    ;
    Schmid, M.
    ;
    Müller, Kajetan
    The relative humidity level in the immediate vicinity of objects such as foods and technical items has an influence on transpiration and undesired relative humidity dependent reactions on their surfaces such as water vapour condensation, chemical reactions and microbial growth. Desirable are therefore materials that regulate the relative humidity to predefined levels in closed spaces such as in packagings and also in housing spaces. Such materials should be able to adjust the surface humidity of objects via water vapour diffusion in the gas phase without being in direct contact. A strategy to create such humidity regulating materials is the use of substances that absorb and desorb high amounts of water vapour, such as sodium chloride. Sodium chloride (NaCl) particles absorb water vapour at a relative humidity above 75% at 23 °C and then they form NaCl solution. NaCl solution desorbs water vapour when the relative humidity in the immediate vicinity decreases below the equilibrium relative humidity of that salt solution. Therefore, this system is able to regulate the relative humidity in its immediate vicinity. A strategy to provide free space in polymeric structures for the NaCl solution is the creation of cavities by foaming and stretching. However, only little knowledge exists about the influence of the combination of both processes on the functional properties of humidity regulating films with salt as active substance. Hence, the aim of this study was to investigate how and to which extend foaming and/or stretching affects the functional properties, i.e. water vapour sorption and mechanical properties, of polypropylene (PP) films containing NaCl particles. For this study, foamed and non-foamed PP with 3 and 6 weight-% NaCl were extruded into films. In the next step, some of these samples were biaxially stretched and their structures, water vapour absorption, porosities and mechanical strengths were analysed. The only-foamed films had a porosity of 0.3, the porosity of only-biaxially stretched films was between 0.1 and 0.2. The porosity increased to 0.7 when the films were first foamed and stretched afterward. Foamed and then stretched films with 6 wt.-% NaCl absorbed a high amount of water vapour from air with a value of 0.8 g H2O/g film at 97% relative humidity. Stretching of filled and non-filled foamed films also resulted in higher mechanical strength of the pure matrix polymer in comparison to the pure matrix polymer of non-stretched films. By the results of this study is shown that humidity regulating films with high water vapour sorption capacity can be produced via extrusion, foaming and stretching processes which are established processes in the polymer industry.
  • Publication
    Gallic acid as an oxygen scavenger in bio-based multilayer packaging films
    ( 2017)
    Pant, Astrid
    ;
    Sängerlaub, Sven
    ;
    Müller, Kajetan
    Oxygen scavengers are used in food packaging to protect oxygen-sensitive food products. A mixture of gallic acid (GA) and sodium carbonate was used as an oxygen scavenger (OSc) in bio-based multilayer packaging films produced in a three-step process: compounding, flat film extrusion, and lamination. We investigated the film surface color as well as oxygen absorption at different relative humidities (RHs) and temperatures, and compared the oxygen absorption of OSc powder, monolayer films, and multilayer films. The films were initially brownish-red in color but changed to greenish-black during oxygen absorption under humid conditions. We observed a maximum absorption capacity of 447 mg O2/g GA at 21 °C and 100% RH. The incorporation of GA into a polymer matrix reduced the rate of oxygen absorption compared to the GA powder because the polymer acted as a barrier to oxygen and water vapor diffusion. As expected, the temperature had a significant effect on the initial absorption rate of the multilayer films; the corresponding activation energy was 75.4 kJ/mol. Higher RH significantly increased the oxygen absorption rate. These results demonstrate for the first time the production and the properties of a bio-based multilayer packaging film with GA as the oxygen scavenger. Potential applications include the packaging of food products with high water activity (aw > 0.86).
  • Publication
    Recycling aktiver und intelligenter Verpackungen
    ( 2017)
    Pitschke, Thorsten
    ;
    Kreibe, Siegfried
    ;
    Pant, Astrid
    ;
    Krüger, Franziska
  • Publication
    Recyclingfähigkeit von aktiven und intelligenten Verpackungen
    ( 2017)
    Pitschke, Thorsten
    ;
    Kreibe, Siegfried
    ;
    Pant, Astrid
    ;
    Krüger, Franziska
  • Publication
    Umweltbezogene Bilanzierung von "intelligenten" und "aktiven" Verpackungen hinsichtlich der Recyclingfähigkeit und Durchführung eines Dialogs mit Akteuren der Entsorgungs- und Herstellungsbranchen
    (UBA, 2017)
    Kreibe, Siegfried
    ;
    Pitschke, Thorsten
    ;
    Berkmüller, Ruth
    ;
    Bokelmann, Monika
    ;
    Förster, Andreas
    ;
    Stramm, Cornelia
    ;
    Pant, Astrid
    Verpackungen werden immer komplexer und es werden zunehmend Komponenten eingesetzt, um ihre Eigenschaften zu verbessern oder ihre Funktionalität zu erhöhen. Hierzu zählen u. a. Beschichtungen zur Verlängerung der Haltbarkeit von Lebensmitteln oder RFID-Chips zur kontaktlosen Identifizierung (Radio Frequency Identification). Das Design einer Verpackung hat jedoch einen entscheidenden Einfluss auf ihre Recyclingfähigkeit. Ziel dieses Projektes war es daher, die Auswirkungen von ""aktiven"" und ""intelligenten"" Verpackungen auf das Recycling zu erheben. Darauf aufbauend wurden Vorschläge für Maßnahmen zur Sicherung der hochwertigen werkstofflichen Verwertung von Verpackungsabfällen erarbeitet.
  • Publication
    A mathematical model for tailoring antimicrobial packaging material containing encapsulated volatile compounds
    ( 2017)
    Kurek, Mia
    ;
    Laridon, Yannick
    ;
    Torrieri, Elena
    ;
    Guillard, Valérie
    ;
    Pant, Astrid
    ;
    Stramm, Cornelia
    ;
    Gontard, Nathalie
    ;
    Guillaume, Carole
    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.