Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

Browse

Filters

2018 - 201922020 - 20241

Settings

Department: search.filters.department.Thesis (Master)--İzmir Institute of Technology, Food EngineeringSubject: search.filters.subject.Food packaging

Search Results

Now showing 1 - 3 of 3
  • Master Thesis
    Development of Pectin-Wax Composite Edible Films With High Moisture Barrier Properties
    (01. Izmir Institute of Technology, 2024) Yemenicioğlu, Ahmet; Yemenicioğlu, Ahmet; Yemenicioğlu, Ahmet; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Bu tez çalışmasında literatürde ilk kez turunçgil pektininin aynı anda hem su buharı geçirgenliği (WVP) düşük, hem de antimikrobiyel etki gösteren çift fonksiyonlu filmlerinin üretilmesi amaçlanmıştır. Bu amaçla ulaşmak için pektinin mumlarla sıcak homojenizasyon yöntemiyle emülsifikasyon yöntemi kullanılarak karvakrol içeren kompozit filmleri üretilmiştir. Pektinin %15 gliserol ve %40 balmumu içeren kompozit filmleri CaCl2'le çapraz bağlandıktan sonra elde edilen en düşük WVP değeri 1.58 g.mm/m2.gün.kPa olarak belirlenmiştir (kontrol pektin filme göre %54 daha düşük WVP). Buna karşın pektinin %15 gliserol ve %30 karnauba mumu kullanılarak elde edilmiş filmleri çapraz bağlama uygulanmadan 0.16 g.mm/m2.gün.kPa gibi çok düşük bir WVP değeri göstermiştir (kontrol pektin filme göre %95.4 daha düşük WVP). Elde edilen bu sonuç karnauba mumu gibi erime noktası yüksek (e.n.=82-86 oC) mum kullanımının erime noktası düşük (e.n.= 62-66 oC) bal mumu kullanımına göre WVP değerini daha etkili düşürdüğünü göstermiştir. Dolayısıyla antimikrobiyal film üretimi amacıyla karnauba mumu içeren pektin film kompozitleri içerisine %1, 2 veya 3 oranında karvakrol ilave edilmiştir. Elde edilen karvakrol içeren tüm filmler Escherichia coli ve Listeria innocua üzerinde esansiyel yağ konsantrasyonuyla orantılı olarak antimikrobiyal etki göstermiştir. Ancak, filmlerin WVP değerleri de ilave edilen esansiyel yağ konsantrasyonu arttıkça artmıştır. Bu nedenle tezde elde edilmiş olan en düşük WVP (1.47 g.mm/m2.gün.kPa) gösteren antimikrobiyal film %1 oranında karvakrol içeren olmuştur (kontrol pektin filme göre %57 daha düşük WVP). Filmlere karnauba mumu ilavesi ışık geçirgenliklerini azaltırken mekaniki özelliklerini de kısmen zayıflatmaktadır. Bu tez çalışması gıdalarda daha az nem kaybına neden olabilecek antimikrobiyel pektin temelli film üretiminin mümkün olduğunu göstermiştir.
  • Master Thesis
    Structure and Gas Transmission Properties of Surface Modified Food Packaging Materials by Layer-By Assembly
    (Izmir Institute of Technology, 2019) Koca, Nazan; Bayramoğlu, Beste; Bayramoğlu, Beste; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    In this study, two different LbL coatings of chicken egg white lysozyme (LZ) (0.2 % w/v)-gum arabic (GA) (0.2 % w/v) and lysozyme (LZ) (0.2 % w/v)-iota carrageenan (IC) (0.2 % w/v) were investigated as a potential agent in the fabricaton of surfacemodified food packaging materials with improved gas barrier properties. The effects of solution pH, adsorption time, number of layers, and inclusion of drying step in between deposition steps on multilayer formation were explored for both LbL coatings seperately. Film growth was monitored up to 10 layers by UV-Vis spectrometry and Surface Plasmon Resonance (SPR), which allows for in situ observation of the multilayer formation. The LbL coatings were characterized by AFM (Atomic Force Microscopy) and SEM (Scanning Electron Microscopy). The oxygen and water vapor transmission rates of the coatings (assembled on corona treated polypropylene (PP) films) were also measured. The most successful LbL assembly was obtained at pH 7-7 combination, with 20 minutes adsorption time and with intermediate drying steps for both (LZ-GA and LZ-IC) LbL coatings. For both LbL coating, both the UV-Vis and SPR measurements showed the similar zig-zag trend; i.e. desorption of some of the pre-adsorbed LZ from the interface with the deposition of GA (or IC) on it, probably due to formation of soluble complexes between them. The importance of intermediate drying steps was established by UV-Vis, AFM and gas transmission rate measurements. The absence of intermediate drying caused a reduction in total mass deposited and the gas barrier properties of the coatings.
  • Master Thesis
    Development of Bio-Based Coatings as Flexible Food Packaging Applications
    (Izmir Institute of Technology, 2018) Adalı, Merve Betül; Korel, Figen; Korel, Figen; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The sustainable packaging solutions require the development of materials based on renewable resources and efficient production methods, which are important nowadays. In this study, a multilayer coated flexible polyethylene terephthalate (PET) sheets were produced by Layer-by-Layer (LbL) assembly using chitosan and pectin bio-based materials incorporated with galls extract (GE) as an active agent. These fabricated films were firstly characterized and results of increasing the depositing of chitosan and pectin from 0 to 60 layers indicated that the deposition of biopolymers successfully improve the performance of flexible films. The optimization of the deposition different number of layer on PET (20 – 40 and 60 layers) was carried out by the study of the surface characterization and the shelf-life tests in order to find out surface modification. The coated LbL films were applied on fresh-cut ‘Abate Fetel’ pears and color, microbial, sensory assays were carried out during 7 days of storage at 4 ºC. At the end of storage, in terms of all tests, the LbL treated samples were presented better preserved compared to the control samples (treated base film). In addition, the release of active agents from multilayer films was evaluated using LbL films in contact with food and gradual reduction was observed. This research demonstrates the feasibility of LbL coating, which acts as a carrier of active substances to enhance the quality of fresh-cut products as an active packaging system.