Food Engineering / Gıda Mühendisliği

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

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Department: search.filters.department.İzmir Institute of Technology. PhysicsPublication Index: search.filters.publicationIndex.PubMed

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  • Article
    Citation - WoS: 24
    Citation - Scopus: 25
    Investigation of the Structure of Alpha-Lactalbumin Protein Nanotubes Using Optical Spectroscopy
    (Cambridge University Press, 2014) Tarhan, Özgür; Tarhan, Enver; Harsa, Şebnem
    Alpha-lactalbumin (α-la) is one of the major proteins in whey. When partially hydrolysed with Bacillus licheniformis protease, it produces nanotubular structures in the presence of calcium ions by a self-assembly process. This study presents investigation of α-la protein structure during hydrolysis and nanotube formation using optical spectroscopy. Before spectroscopic measurements, nanotubes were examined with microscopy. The observed α-la nanotubes (α-LaNTs) were in the form of regular hollo strands with a diameter of about 20 nm and the average length of 1 μm. Amide and backbone vibration bands of the Raman spectra displayed remarkable conformational changes in α and β domains in the protein structure during nanotube growth. This was confirmed by the Fourier-transform infrared (FTIR) spectroscopy data. Also, FTIR analysis revealed certain bands at calcium (Ca++) binding sites of COO- groups in hydrolysed protein. These sites might be critical in nanotube elongation.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 16
    Humidity Adsorption Kinetics of a Trypsin Gel Film
    (Elsevier Ltd., 2012) Okur, Salih; Ceylan, Çağatay; Çulcular, Evren
    This study focuses on the humidity adsorption kinetics of an isopropanol-induced and pH-triggered bovine pancreatic trypsin gel (BPTG). The BPTG was adsorbed on a gold coated Quartz Crystal Microbalance (QCM) substrate with a thickness of 376nm. The morphology of the film was characterized using Atomic Force Microscopy (AFM). QCM was used to investigate the humidity sensing properties of the BPTG film. The response of the humidity sensor was explained using the Langmuir model. The average values of adsorption and desorption rates between 11% RH (relative humidity) and 97% RH were calculated as 2482.5M -1s -1 and 0.02s -1, respectively. The equilibrium constant and average Gibbs Free Energy of humidity adsorption and desorption cycles were obtained as 133,000 and -11.8kJ/mol, respectively. © 2011 Elsevier Inc..