Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Comparative Optimization of Hot Water and Citric Acid Extraction Methods for Sericin Recovery From Silk Cocoons: In Vitro Antioxidant and Antidiabetic Activities(Springer, 2026) Sincar, Bahar; Ozdemir, Feyza; Bicakci, Beyza Tutku; Erdem, Cansu; Yalcin, Dilek; Alamri, Abdulhakeem S.; Bayraktar, OguzSilk sericin, a hydrophilic protein derived from Bombyx mori cocoons, has attracted increasing interest due to its antioxidant, moisturizing, and enzyme-inhibitory properties. Efficient extraction is essential to preserve its biofunctional potential. In this study, sericin was extracted using hot water and 1.25% (w/v) citric acid using autoclave-based heating to achieve pressurized conditions above 100 degrees C. A Box-Behnken Response Surface Methodology (RSM) was applied to systematically evaluate the effects of extraction parameters (temperature and time) and to optimize five key response variables: yield, purity, molecular weight and polydispersity index (PDI), total antioxidant capacity (ABTS), and alpha-glucosidase inhibition activity. The results revealed that higher temperatures (125 degrees C) produced the maximum sericin yield, while moderate conditions (115 degrees C for 45 min) ensured better preservation of antioxidant and antidiabetic activities. Hot acid extraction resulted in significantly enhanced purity and enzymatic inhibition compared to hot water extraction. Sericin fractions above 7 kDa exhibited the strongest bioactivity, as reflected by lower IC50 values in both ABTS and alpha-glucosidase inhibition assays. The optimized hot water citric acid-based method yielded 24.00% sericin with 100.00% purity and an IC50 of 0.67 mg/mL for alpha-glucosidase inhibition. This study compares hot water and hot acid autoclave extractions using Box-Behnken design and evaluates their effects on sericin yield, purity, and bioactivities. Citric acid-based extraction produced higher purity and stronger alpha-glucosidase inhibition, while hot water extraction preserved antioxidant potential more effectively. These findings support the use of citric acid as an eco-friendly and scalable extraction agent and highlight the potential of sericin in biomedical and nutraceutical applications.Article Techno-Functional and Antioxidant Properties of Chickpea Proteins Interacted with Green Tea Phenolics-Exploring Benefits for Gel and Emulsion-Based Vegan Foods(Elsevier, 2025) Kavur, Pelin Baris; Sahin, Damla Oyku; Cavdaro Glu, Elif; Buyuk, Miray; Cakitli, Gamze; Hamzaoglu, Fatmagul; Yemenicioglu, AhmetThis study aimed at exploiting protein-polyphenol interactions to enhance techno-functional and antioxidant properties of chickpea proteins. For this purpose, prior to protein extraction, chickpeas were rehydrated in green tea infusion (GTI). Extracted chickpea proteins (CPCGTI) contained free (90.7 mu g/g) and bound (32.0 mu g/g) green tea phenolics (e.g., gallic acid, catechin, epigallocatechin 3-gallate, epicatechin 3-gallate). A close association between chickpea protein and green tea polyphenols was determined considering pH-solubility profile of CPCGTI. CPCGTI showed superior antioxidant potential (6.5-fold), water/oil absorption capacity (1.4-1.5-fold), and gel firmness than control chickpea protein (CPCC). Edible films of CPCGTI also showed 2.4-fold higher antioxidant capacity than those of CPCC. CPCGTI and CPCC showed similar SDS-PAGE patterns, but different alpha-helix and beta-sheet contents evaluated by FTIR. CPCGTI gave thick, creamy and stable mayonnaise while CPCC failed to form mayonnaise. The coconut milk pudding with CPCGTI showed better gelation than that with CPCC. However, foods with CPCGTI had a darker color than those with CPCC. CPCGTI is a novel, highly functional ingredient for manufacturing plant-based food and edible packaging.Review Citation - WoS: 7Citation - Scopus: 7Ultrasonication Effects on Quality of Tea-Based Beverages(MDPI, 2023) Uzuner, SibelTea is the most popular consumed drink after water. Teas and tea-based beverages have grown in popularity due to bioactive compounds. Tea-based beverages have started to take their place in the market. Extraction is a crucial step for the production of functional tea-based beverages. Compared to conventional methods, ultrasound is attractive due to its lower energy requirements, and shorter extraction time. This review aimed to discuss recent marketing aspects of tea-based beverages as well as the potential and challenges of a novel infusion technique. This review describes the health benefits and technological aspects of tea-based beverages in relation to how to best solve nutritional and microbial concerns. Current and future challenges and opportunities of the novel infusion technique and its scaling-up for the extraction of bioactive compounds are also covered in the present review.Article Citation - WoS: 36Citation - Scopus: 38Phytochemical Screening and Evaluation of the Antimicrobial and Antioxidant Activities of Ferula Caspica M. Bieb. Extracts(King Saud University, 2019) Kahraman, Çiğdem; Topçu, Gülaçtı; Bedir, Erdal; Tatlı, İ. İrem; Ekizoğlu, Melike; Akdemir, Zeliha S.Chloroform, ethyl acetate and methanol extracts from the aerial parts of Ferula caspica M. Bieb. were tested for their antioxidant capacities by CUPRAC, ABTS, FRAP, Folin-Ciocalteu and aluminum chloride methods and for antimicrobial activities by the broth microdilution method. Chloroform and ethyl acetate extracts showed the highest antioxidant capacity and antimicrobial activity. Three known sesquiterpene derivatives; 1-(2',4'-dihydroxyphenyl)-3,7,11-trimethyl-3-vinyl-6(E), 10-dodecadien-1-one (1), 2,3-dihydro-7-hydroxy-2,3-dimethyl-2-[4',8'-dimethyl-3',7'-nonadienyl]-furo[3,2,c]coumarin (2), 2,3-dihydro-7-hydroxy-2,3-dimethyl-3-[4',8'-dimethyl-3',7'-nonadienyl]-furo[3,2,c]coumarin(3); phenylpropanoid; laserine/2-epilaserine (4/5) and steroid mixtures; stigmasterol and beta-sitosterol (6/7) were isolated from chloroform extract; three known flavonoids; kaempferol-3-O-beta-glucopyranoside (8), kaempferol-3-O-alpha-rhamnopyranoside (9), quercetin-3-O-beta-glucopyranoside (10), and one benzoic acid derivative; 2,4-dihydroxybenzoic acid (11) were isolated from the ethyl acetate extract. The structures were elucidated by spectroscopic methods. (C) 2019 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.Book Part Citation - WoS: 30Citation - Scopus: 41Nanocarriers for Plant-Derived Natural Compounds(Elsevier Ltd., 2017) Bayraktar, Oğuz; Erdoğan, İpek; Köse, Merve D.; Kalmaz, GülcanNatural products constitute a large fraction in drug discovery processes. The term includes compounds from plants, microorganisms, and animals. Most of the natural products are secondary metabolites derived from plants, which are low in amounts and difficult to isolate. Another issue is the preservation of their bioactivity during process and storage as well as degradation in the gastrointestinal system before reaching circulation. Advances in nanotechnology offer nanoparticles, nanocapsules, and conjugates, which are devoted to site-specific, time-controlled delivery of bioactive agents. Nanoencapsulated systems have the advantage of high drug encapsulation efficiency because of optimized drug solubility in the core, low polymer content compared to other nanoparticulated systems such as nanospheres, drug polymeric shell protection against degradation factors, and the reduction of tissue irritation caused by the polymeric shell. This chapter will discuss nanoencapsulation methods and advances in carrier systems for plant-derived natural compounds.Book Part Citation - WoS: 3Citation - Scopus: 4Physiology of Metabolites(CABI Publishing, 2012) Frary, Amy; Frary, AnneThis chapter provides an overview of recent research on the effects of genotype fruit development and growing conditions on the synthesis and concentrations of the following metabolites in pepper (Capsicum spp.): antioxidants, carotenoids, phenolic compounds, capsaicinoids, flavonoids and vitamin C.Article Citation - WoS: 62Citation - Scopus: 73Antioxidant and Antimicrobial Activities of Thyme and Clove Essential Oils and Application in Minced Beef(John Wiley and Sons Inc., 2015) Zengin, Hatice; Baysal, Ayşe HandanIn this study, thyme and clove essential oils (EOs) were studied for their chemical composition, antioxidant, antiradical and antibacterial activity and application in ground beef. Carvacrol (75.27%) and eugenol (75.2%) were detected by gas chromatography-mass spectrometry analysis as the main components of thyme and clove EOs, respectively. Broth microdilution method showed all bacteria inhibited by the EOs, while Shewanella putrefaciens and Listeria innocua were the most resistant bacteria to thyme and clove EOs, respectively. EO treatment restricted the growth of artificially inoculated Salmonella typhimurium and native Coliforms in the ground beef. Antioxidant activity determined by ferric-reducing antioxidant power and 1,1 diphenyl-2-picrylhydrazyl methods demonstrated that clove EO had higher in vitro antioxidant activity than thyme EO. Similar results were obtained in ground beef application using 2-thiobarbituric acid value. EOs of clove (2MIC) exerted remarkable higher antioxidant activity in ground beef than EOs of thyme (4MIC), which represent valid alternative antioxidant in meat products. Practical Applications: Plant essential oils (EOs) serve as a "safe" alternative to chemical or synthetic antimicrobials and antioxidants to struggle with the foodborne pathogens or spoilage organisms, inhibiting lipid oxidation and thus extending shelf life. Antioxidant activity determined by ferric-reducing antioxidant power and 1,1 diphenyl-2-picrylhydrazyl methods showed that clove EO had higher in vitro antioxidant activity than thyme EO. Results obtained using 2-thiobarbituric acid value in ground beef application were found similar. EOs of clove (2MIC) exerted higher antioxidant activity in ground beef than EOs of thyme (4MIC). Therefore, EOs could be a valid alternative antioxidant in meat products.Article Citation - WoS: 31Citation - Scopus: 32Immobilization of Alpha Lipoic Acid Onto Polysulfone Membranes To Suppress Hemodialysis Induced Oxidative Stress(Elsevier Ltd., 2014) Yaşar Mahlıçlı, Filiz; Alsoy Altınkaya, SacideAlpha-lipoic acid (ALA) immobilized polysulfone (PSF) hemodialysis membranes have been fabricated by the dry-wet phase inversion technique. The antioxidant properties of the membranes were evaluated in terms of inhibition of reactive oxygen species (ROS) in blood plasma, while their blood compatibilities were determined by quantitating plasma protein adsorption, platelet adhesion, activation and cytotoxicity to blood cells. The stability of ALA under typical hemodialysis conditions was improved by immobilization, and the greatest enhancement was achieved when it was sandwiched between two polyethyleneimine (PEI) layers. In vitro antioxidant activity measurements showed that ALA coated membranes are not only capable of reducing ROS levels in blood, protein adsorption and platelet activation on the membranes, but, can also prolong coagulation time. All membranes prepared were noncytotoxic to peripheral blood mononuclear cells. In addition, the high permeation rates of solutes through PSF membrane were not affected by ALA immobilization.Article Citation - WoS: 19Citation - Scopus: 22Absence of Superoxide Dismutase Activity Causes Nuclear Dna Fragmentation During the Aging Process(Academic Press Inc., 2014) Muid, Khandaker Ashfaqul; Karakaya, Hüseyin Çaglar; Koç, AhmetSuperoxide dismutases (SOD) serve as an important antioxidant defense mechanism in aerobic organisms, and deletion of these genes shortens the replicative life span in the budding yeast Saccharomyces cerevisiae. Even though involvement of superoxide dismutase enzymes in ROS scavenging and the aging process has been studied extensively in different organisms, analyses of DNA damages has not been performed for replicatively old superoxide dismutase deficient cells. In this study, we investigated the roles of SOD1, SOD2 and CCS1 genes in preserving genomic integrity in replicatively old yeast cells using the single cell comet assay. We observed that extend of DNA damage was not significantly different among the young cells of wild type, sod1Δ and sod2Δ strains. However, ccs1Δ mutants showed a 60% higher amount of DNA damage in the young stage compared to that of the wild type cells. The aging process increased the DNA damage rates 3-fold in the wild type and more than 5-fold in sod1Δ, sod2Δ, and ccs1Δ mutant cells. Furthermore, ROS levels of these strains showed a similar pattern to their DNA damage contents. Thus, our results confirm that cells accumulate DNA damages during the aging process and reveal that superoxide dismutase enzymes play a substantial role in preserving the genomic integrity in this process.Article Citation - WoS: 7Citation - Scopus: 10Biotechnology for Enhanced Nutritional Quality in Plants(Taylor and Francis Ltd., 2013) Uncu, Ayşe Özgür; Doğanlar, Sami; Frary, AnneWith almost 870 million people estimated to suffer from chronic hunger worldwide, undernourishment represents a major problem that severely affects people in developing countries. In addition to undernourishment, micronutrient deficiency alone can be a cause of serious illness and death. Large portions of the world population rely on a single, starch-rich crop as their primary energy source and these staple crops are generally not rich sources of micronutrients. As a result, physical and mental health problems related to micronutrient deficiencies are estimated to affect around two billion people worldwide. The situation is expected to get worse in parallel with the expanding world population. Improving the nutritional quality of staple crops seems to be an effective and straightforward solution to the problem. Conventional breeding has long been employed for this purpose but success has been limited to the existing diversity in the gene pool. However, biotechnology enables addition or improvement of any nutrient, even those that are scarce or totally absent in a crop species. In addition, biotechnology introduces speed to the biofortification process compared to conventional breeding. Genetic engineering was successfully employed to improve a wide variety of nutritional traits over the last decade. In the present review, progress toward engineering various types of major and minor constituents for the improvement of plant nutritional quality is discussed. © 2013 Copyright Taylor and Francis Group, LLC.