Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Investigation of Structural and Biological Activities of D-Glucose D-Glucose and Bread Melanoidins(01. Izmir Institute of Technology, 2022) Elci, Ferhat; Ceylan, Çağatay; Şahin, İpekAs a result of Maillard reactions, high molecular weight compounds known melanoidins are formed from the proteins and sugars in food. Amino acids and reducing sugars combine, making them common ingredients in meals, fruit juices, coffee, and baked products that are consumed on a regular basis. Food melanoidins can affect human health, thus it's critical to assess and understand their chemical composition. Understanding the relationship between melanoidins' structural analysis and their activity was the main objective of this work. According to our observations, melanoidins have an antibacterial effect on the microorganisms E. coli and S. aureus. Melanoidins demonstrated excellent antibacterial action against E. coli at low doses, whereas S. aureus was more resistant at higher concentrations. These data suggested that melanoidins have a significant level of activity against gram-negative bacteria. The antioxidant capacity of melanoidins was assessed using the ABTS test. The bread melanoid exhibited the lowest antioxidant value, whereas the Gly - Glc melanoid model system had the strongest antioxidant property. Fourier transform Infrared (FTIR) spectroscopy was utilized to identify the functional groups of melanoidins and to analyze these groups. HPLC was used to identify melanoidins. We investigated the structural and functional properties of melanoidins utilizing spectroscopic methods such as FTIR spectroscopy, UV-Visible Spectroscopy, Scanning Electron Microscopy, and biochemical approaches. Studies on their biological activities and structures have enhanced our understanding of them; yet the complexity of the structures and variety of melanoidins provide the greatest obstacle to the knowledge.Master Thesis Optimizing the Dispersion of Ceramic Nanoparticles and Assessing the Role of Aggregation in Mediating Biological Activity(Izmir Institute of Technology, 2022) Önder, Anıl Can; Öksel Karakuş, Ceyda; Öksel Karakuş, CeydaThe aim of this study is to optimize the sample preparation protocol for dispersing powder-form ceramic nanoparticles (CeNPs) in liquid media by leveraging the power of the design of experiment approach to narrow down potential causes of aggregation and to investigate the subsequent effect of CeNP aggregation on the biological activity of SaOS-2 human osteosarcoma cells. Dispersion of the nanopowders is one of the problems in the nanotechnology field because of the tendency of the nanoparticles for aggregation. Although there are existing dispersion protocols, they offer a one-size-fits-all approach overseeing the unique physicochemical properties of the different nanomaterials. In this study, optimization of the sample preparation protocol for two CeNPs was assessed via the investigation of the most contributing parameters and their synergetic effect through measurements of Z-average and zeta potential. Evaluation of these parameters allowed the development of two different models for each nanomaterial, predicting Z-average and zeta potential for given parameter sets. Through these models, two different sample sets were selected to evaluate the effect of aggregation on the SaOS-2 cell line. Outcomes show that the concentration of nanomaterial, pH, and the presence of additive molecule are three main parameters that affect dispersion stability. It was seen that these parameters can be included in a design to develop an efficient model to predict Z-average and zeta potential for investigated nanomaterials. Moreover, cell viability tests show that there is no significant difference between untreated and nanomaterial-treated cells. The findings promise that tailor-made and reliable dispersion protocols for different nanopowders can be developed via design of experiment.