Food Engineering / Gıda Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/12

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  • Article
    Citation - WoS: 80
    Citation - Scopus: 107
    Application of Active Zein-Based Films With Controlled Release Properties To Control Listeria Monocytogenes Growth and Lipid Oxidation in Fresh Kashar Cheese
    (Elsevier Ltd., 2013) Uysal Ünalan, İlke; Arcan, İskender; Korel, Figen; Yemenicioğlu, Ahmet
    The antimicrobial and antioxidant potential of zein and zein-wax composite films having different release profiles for lysozyme and mixture of lysozyme, catechin and gallic acid were tested on cold-stored fresh Kashar cheese inoculated with Listeria monocytogenes ATCC 7644. All lysozyme containing films prevented the increase of L. monocytogenes counts in Kashar cheese for 8 weeks at 4°C, but it was only the zein-wax composite films with sustained lysozyme-release rates which caused a significant reduction (- 0.4 decimals) in initial microbial load of inoculated cheese samples. The mixture of catechin and gallic acid improved the in vitro antimicrobial effect of films against L. monocytogenes, but showed no considerable antimicrobial effect in cheese. However, the films containing catechin and gallic acid were effective in preventing oxidative changes in cheese. This study showed the possibility of increasing safety and quality of fresh cheeses by use of active packaging employing natural antimicrobial compounds and controlled release technology. Industrial relevance There has been a growing interest to develop the functional properties of packaging materials and to obtain packed foods with better shelf-life and quality. Active packaging incorporating antimicrobials is one of the most promising areas since application of this method can improve safety of foods by inhibiting pathogenic bacteria or controlling spoilage flora by using minimum amounts of active compounds. Recently, health concerns of consumers and environmental problems related to plastics increased the popularity of using natural antimicrobial substances in edible films and coatings. This work employs a GRAS status natural antimicrobial lysozyme and zein a major by-product of rapidly growing oil and bioethanol industries which can form self-standing films, coatings or casings. The results of this study showed the possibility of using flexible antimicrobial and antioxidant films with controlled release properties in diary industry.
  • Article
    Citation - WoS: 153
    Citation - Scopus: 192
    Development of Cellulose Acetate Based Antimicrobial Food Packaging Materials for Controlled Release of Lysozyme
    (Elsevier Ltd., 2009) Gemili, Seyhun; Yemenicioğlu, Ahmet; Alsoy Altınkaya, Sacide
    Antimicrobial packaging materials were obtained by incorporation of lysozyme into cellulose acetate (CA) films. In order to achieve controlled release of lysozyme, the structure of the films was changed from highly asymmetric and porous to dense by modulating the composition of the initial casting solution. The highest release rate, soluble lysozyme activity and antimicrobial activity were obtained with the film prepared from 5% CA solution including 1.5% lysozyme. Increasing CA content in the casting solution decreased the porosity of the films, hence, reduced the release rate, maximum released lysozyme activities and the antimicrobial activities of the films. In contrast, immobilized lysozyme activities and the tensile strength of the films increased. The incorporation of lysozyme did not cause significant reductions in tensile strength and elongation at break values except in films prepared with 15% CA. This study showed the good potential of asymmetric CA films to achieve controlled release in antimicrobial packaging.
  • Article
    Citation - WoS: 87
    Citation - Scopus: 111
    Development of Antioxidant Food Packaging Materials With Controlled Release Properties
    (Elsevier Ltd., 2010) Gemili, Seyhun; Yemenicioğlu, Ahmet; Alsoy Altınkaya, Sacide
    In this study, cellulose acetate (CA) films with different morphological features were prepared in order to control the release rates of low molecular weight natural antioxidants, L-ascorbic acid and L-tyrosine. Increasing CA content in the casting solution decreased the average pore size and porosity of the films, thus, reduced the diffusion rates of both antioxidants through the films. Although both antioxidants have similar molecular weights, L-tyrosine released into water much more slowly than L-ascorbic acid. The highest antioxidant activity in release test solutions was observed with highly porous L-tyrosine containing films. However, when the porosity of the films reduced, the antioxidant activity of L-ascorbic acid released into solution was found to be higher due to trapping of significant amount of L-tyrosine in dense films. The use of different antioxidants caused different changes in morphological and mechanical properties of the CA films. Varying the structural features of the films with the preparation conditions or using different surfaces of the films allowed the controlled release of each antioxidant. © 2009 Elsevier Ltd. All rights reserved.