Kimya - Metalurji Fakültesi

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http://hdl.handle.net/11527/17537

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Yazar "Dikmetaş, Dilara Nur" ile Kimya - Metalurji Fakültesi'a göz atma
  • Öge
    Plasma treated-double layer electrospun fiber mats from thermoplastic polyurethane and gelatin for wound healing applications
    (Wiley, 2024) Yıldırım, Arzu ; Erdoğan, Eray Sarper ; Çağlayan, Şeyma ; Keskinkaya, Rüya ; Türker, Yurdanur ; Karbancıoğlu-Güler, Funda ; Dikmetaş, Dilara Nur ; Batirel, Saime ; Erol Taygun, Melek ; Guner, F. Seniha ; orcid.org/0000-0002-3414-4868 ; Kimya Mühendisliği
    Conventional wound treatment options provide a barrier against exogenous microbial penetration but cannot simultaneously provide an antibacterial characteristic and promote healing. However, bioactive dressings can accelerate wound healing and have an antibacterial effect in addition to being able to cover and protect lesions. In this study, double-layer thermoplastic polyurethane (TPU)-gelatin fibrous dressings that mimic the epidermis and dermis layers of the skin were fabricated via electrospinning technique. As a bioactive agent, Hypericum perforatum oil (HPO) was utilized to impart antibacterial and therapeutic properties to the dressings. Tannic acid was also used in fiber mat formulations as a cross-linking agent. Oxygen plasma treatment was applied as a surface activation technique to improve adhesion of TPU and gelation layers. The fiber structure of the mats was revealed by a scanning electron microscopy (SEM) study. Fourier transform infrared (FTIR) spectroscopy was used to demonstrate HPO loading onto the mats. The water vapor transmission rate (WVTR) and fluid absorbency of the mats were compared with some commercial dressings. According to these results, it can be suggested that the mats can be used for moderate to high exudative wounds. All dressings, even the control sample showed antibacterial features against both Staphylococcus aureus and Escherichia coli bacteria due to the tannic acid. In vitro wound healing assays were carried out on the plasma-treated sample and it was observed that the sample did not negatively affect the migration and proliferation abilities of the cells which are necessary for wound healing. Overall results indicated that the plasma-treated fibrous mat would be a good candidate as a wound dressing material having an antibacterial character.
  • Öge
    Recent Insights into the Use of Antagonistic Yeasts for Sustainable Biomanagement of Postharvest Pathogenic and Mycotoxigenic Fungi in Fruits with Their Prevention Strategies against Mycotoxins
    (American Chemical Society, 2023-06-23) Karbancıoğlu Güler, Funda ; Öztekin, Sebahat ; Dikmetaş, Dilara Nur ; Devecioğlu, Dilara ; Acar, Emine Gizem ; 0000-0001-6576-0084 ; Food Engineering
    Fungi-induced postharvest diseases are the leading causes of food loss and waste. In this context, fruit decay can be directly attributed to phytopathogenic and/or mycotoxin-producing fungi. The U.N. Sustainable Development Goals aim to end hunger by 2030 by improving food security, sustainable agriculture, and food production systems. Antagonistic yeasts are one of the methods presented to achieve these goals. Unlike physical and chemical methods, harnessing antagonistic yeasts as a biological method controls the decay caused by fungi and adsorbs and/or degrades mycotoxins sustainably. Therefore, antagonistic yeasts and their antifungal mechanisms have gained importance. Additionally, mycotoxins’ biodetoxification is carried out due to the occurrence of mycotoxin-producing fungal species in fruits. Combinations with processes and agents have been investigated to increase antagonistic yeasts’ efficiency. Therefore, this review provides a comprehensive summary of studies on preventing phytopathogenic and mycotoxigenic fungi and their mycotoxins in fruits, as well as biocontrolling and biodetoxification mechanisms.
  • Öge
    Sequential extraction and characterization of essential oil, flavonoids, and pectin from industrial orange waste
    (American Chemical Society, 2024) Dikmetaş, Dilara Nur ; Devecioğlu, Dilara ; Karbancıoğlu-Güler, Funda ; Kahveci, Derya ; 0000-0002-1514-7166 ; 0000-0001-6681-0944 ; 0000-0001-6576-0084 ; 0000-0003-0450-5682 ; Gıda Mühendisliği
    Orange is one of the primary fruits processed into juice and other products worldwide, leading to a vast amount of waste accumulation. Such waste has been considered as an attractive candidate for upcycling to obtain bioactive components remaining. The present study investigated the extraction of essential oil (EO), flavonoids, and pectin from industrial orange waste with a holistic approach. To maximize EO yield and d-limonene concentration, hydrodistillation (HD) conditions were selected to be 5.5 mL water/g solid for 180 min. Remaining solids were further used for flavonoid extraction where conventional solvent, sequential ultrasound + solvent, and ultrasound-assisted extraction (UE) were applied. UE applied for 50 min with 120 mL solvent/g solid yielded the highest total phenolic (TPCs) and total flavonoid contents (TFCs), antioxidant capacity, and hesperidin and neohesperidin concentrations. In terms of TPC, TFC, antioxidant capacity, and antibacterial activity, both EO and flavonoid fractions demonstrated moderate to high bioactivity. At the final step, ethanol precipitation was applied to obtain the pectin that was solubilized in hot water during HD and it was characterized by Fourier transform infrared, degree of esterification, and galacturonic acid content. Practical application: to ensure utilization in the food, pharmaceutical, and cosmetic industries, this study presents a combined method to obtain several value-added compounds from industrial orange waste. Bioactive EO and flavonoids obtained could have applications in functional food, supplements, or cosmetic formulations, whereas extracted pectin can be used in many formulated foods and drugs.