Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Effect of Edible Film and Allicin on Shelf Life of Chicken Meat(01. Izmir Institute of Technology, 2024) Cancı, Şeyda; Baysal, Ayşe HandanTavuk eti besleyici değeri sebebiyle sağlıklı beslenme için önemli bir gıdadır ve büyüme çağındaki çocuklar ve yaşlılar gibi toplumun çoğu popülasyonu tarafından tüketilen bir gıdadır. Ancak tavuk eti kolay bozulabilen bir gıdadır ve bunun önüne geçmek için yenilebilir kaplamalardan ve biyoaktif bileşenlerden yararlanılmaktadır. Bu çalışmada, kitosanın antibakteriyel, antimikrobiyal, biyouyumlu ve biyolojik olarak parçalanabilir özellikleri ve allisinin antimikrobiyal, antifungal ve antioksidan özellikleri kullanılarak tavuk bagetlerdeki raf ömrüne etkisi incelenmiştir. Tavuk bagetlerin, farklı konsantrasyonlarda hazırlanan kitosan ve allisin çözeltileriyle K1A1(1% Kitosan + 10% Allisin), K1A2 (1% Kitosan + 20% Allisin), K2A1(2% Kitosan + 10% Allisin), K2A2(2% Kitosan + 20% Allisin) ve sadece kitosanın farklı konsantrasyonlarını içeren çözeltileriyle (%1 Kitosan, %2 Kitosan) kaplanması, mikrobiyolojik özellikleri, duyusal özellikleri, kimyasal parametleri, oksidatif bozulma parametreleri belirlenen raf ömrü boyunca 4 ⸰C'de saklanarak değerlendirilmiştir. Kitosan ve allisin ile kaplanan numunelerde ve kitosan çözeltisiyle kaplanmış numunelerde kontrol grubuna kıyasla toplam canlı, Enterobacteriaceae, Pseudomonas bakteri sayımlarında, bakteri sayısı önemli ölçüde azalmıştır. Toplam canlı gelişimini engellemede en etkili sonuç, tavuk bagetlerin raf ömrünü uzatan K2A1 örnek grubuyla elde edildi. Depolamanın 10. günündeki TBA sonuçlarında, %1 kitosanla kaplanmış tavuk bagetlerin 0.33 mg MDA/kg değeriyle lipid oksidasyonunu engellemede en başarılı grup olduğu bulunmuştur. Bu sonuçtan sonra en başarılı sonuç 0.55 mg MDA/kg değeriyle K1A2 örneği olmuştur. Anahtar Kelimeler: Allisin, Antimikrobiyal,Antioksidan, Kitosan, TBA, Toplam canlıMaster Thesis Investigation of Antimicrobial, Antioxidant and Cytotoxic Properties of Some Green Leaf Plants(2023) Çetin, Elif Nur; Baysal, Ayşe Handan; Özen, Fatma BanuThe present study aims to investigate the chemical composition, antimicrobial activity, antioxidant properties, and cytotoxic activity of extracts obtained from leaf samples that are discarded as waste products. For this purpose, two different green leaves were selected: one is the grape (Vitis vinifera) leaf, a by-product from the winemaking process, and the other is the cauliflower (Brassica oleracea, var. botrytis) leaf, which is a waste product of cauliflower, and they were subjected to related tests. Both leaf samples were extracted by water because of its easy accessibility and environmentally friendly properties. Leaf extracts were examined according to their total phenolic content and subjected to chemical characterization by Liquid chromatography-quadrupole time-of-flight tandem mass spectrometry system. The promising antioxidant activities of the water-extracted leaf samples were authenticated through DPPH and ABTS assays. Antimicrobial and antibiofilm activities were examined against some Gram-positive (Bacillus cereus, Listeria innocua, and Carnobacterium divergens) and Gram-negative (Escherichia coli, Serratia liquefaciens, and Salmonella Typhimurium) strains, and two fungi (Saccharomyces cerevisiae and Candida albicans) species. Both tested leaf extracts showed a dose-dependent antimicrobial activity, while the antimicrobial activity of grape leaf extract was slightly higher. However, their activities against biofilm formation were varying in different bacterial and fungi species. The cytotoxic activity of the leaf extracts was examined on the mouse fibroblast cell (L929) line. According to the presented results, neither of the leaf extract samples used in the study showed any unwholesome effects on the cell line at any time point.Master Thesis Antimicrobial, Antioxidant, Antiproliferative and Cytotoxic Activities of Aronia Fruit Extract(01. Izmir Institute of Technology, 2023) Tanağardı, Dilaranur; Baysal, Ayşe Handan; Sezgin, EfeAronia melanocarpa contains high amounts of phenolic compounds, especially anthocyanins. Because of its high chemical content and significant antioxidant action, this food is known as a functional food, and its use is spreading worldwide. Within the scope of this thesis research, studies were carried out on Aronia melanocarpa dry extract and liquid extract. For these purposes, chromatographic and chemical profile were determined in detail by HPLC (High-Pressure Liquid Chromatography), Fourier-Transform Infrared Spectroscopy (FTIR) and Q-TOFF- MS (Quadrupole Time of Flight Mass Spectrometry), and significant bioactive were determined. Spectroscopic methods were used to characterize phenolic, anthocyanin, and flavonoid components. Aronia melanocarpa dry and liquid extracts were tested for antioxidant activity using DPPH and ABTS methods. The antioxidant potential of the Aronia melanocarpa dry and liquid extracts studied is high. To test the antiproliferative and cytotoxic effects, cytotoxic studies were performed on the CaCo2 cell line. Cell migration was also studied in HUVEC and HaCat cell lines. The antimicrobial activity of Aronia melanocarpa dry extract and liquid extract was tested against Saccharomyces cerevisiae, a yeast species, and bacterial strains of Staphylococcus aureus, Escherichia coli O157:H7, Salmonella Typhimurium. The extracts analyzed showed an antimicrobial effect on the tested bacteria at different concentrations. The results obtained in this study emphasize that the tested Aronia melanocarpa dry extract and liquid extract have antimicrobial properties. Chromatographic, chemical, and cytological data reveal that Aronia melanocarpa liquid and dry extracts can be used as antioxidative and antiproliferative products as food supplements in the health field.Master Thesis Development of Biosensors for Determination of the Total Antioxidant Capacity(Izmir Institute of Technology, 2008) Çoban, Seçil; Bayraktar, OğuzIn this study, an amperometric laccase biosensor was developed for determination of the oleuropein concentration that is the biological active component of olive leaf and contributes dominantly to the total antioxidant capacity. The biosensor was prepared by immobilization of laccase from Trametes versicolor by addition of cross-linking agent, glutaraldehyde, into the carbon paste electrode. Different biosensors were prepared by changing the amount of crosslinking agent and concentration of the enzyme solution. So, effect of these parameters on biosensor performance was investigated. The best biosensor performance was determined for the biosensor having glutaraldehyde amount of 12.03 % vol. of the biosensor bottom part and 5 mg/ml of laccase enzyme. The effect of scan rate and temperature on the biosensor performance was also investigated in this study. The scan rate of 10 mV/s was decided to be the optimum for the amperometric detection of oleuropein considering the fastest response and maximum reduction current. 250C was chosen as an optimum temperature value due to the maximum laccase activity and capability of oleuropein acting as an antioxidant. Extraction of phenolics from olive leaf was also an important part of this study. The extract was divided into fractions varying in their oleuropein amounts such as polar fractions and relatively less polar fractions. Therefore, biosensor performance was investigated for fractions containing different type of phenolics. HPLC analyses of the fractions were also performed in this study. In addition total phenol content and antioxidant capacity of the fractions were determined by conventional methods.Master Thesis Determination of Genetic Diversity and Antioxidant Content of the National Melon (cucumis Melo) Collection(Izmir Institute of Technology, 2008) Şığva, Hasan Özgür; Frary, Anne; Frary, AnneIn this study, characterization with 19 morphological criteria and two types of PCRbased molecular marker systems, Simple Sequence Repeats (SSRs, microsatellites) and Amplified Fragment Length Polymorphisims (AFLPs), were used to characterize genetic variability among 238 national melon (Cucumis melo L.) accessions and 12 different members of the Cucurbitaceae family.According to morphological analysis, all accessions were vigourous. The accessions showed a great variety of fruit shape, 53 (38.4%) accessions were globular (round), 51 (37.0%) were eliptical, 15 (10.9%) were ovate, 7 (5.1%) oblate, 2 (1.4%) elongate and one accession was flattened. Another agronomically important criterion was predominant fruit skin colour. A total of 55 (39.9%) accessions had light yellow predominant skin colour, 34 (24.6%) were pale green, 29 (21.0%) were orange, 9 (6.5%) were cream, 6 (4.4%) were green, 4 (2.9%) were blackish-green and 1 (0.7%) was dark green.In accordance with genetic characterization, a total of 345 polymorphic AFLP fragments (products of 10 AFLP primer combinations) and 93 SSR fragments (products of 12 SSR markers) were detected and used to calculate genetic distance using DICE matrix and UPGMA (Unweighted Pair Group Method) arithmetical averages. The average polymorphic AFLP fragments per combination was 34.5 and SSR fragments per marker was 7.75. The phylogenetic tree showed that groups were clearly separated by both marker systems. This study allowed the identification of the relationship between national melon accessions based on genetic similarity or differences.Forty three melon accessions were also analyzed for total water soluble antioxidant and total phenolic compound activities.Master Thesis Characterization of Antioxdant Activity and Protein Functionality in Some Legume Cultivars Grown in Turkey(Izmir Institute of Technology, 2008) Aydemir, Levent Yurdaer; Yemenicioğlu, AhmetTurkish chickpeas (4 cultivars) and lentils (6 cultivars) show similar total phenolic contents and free radical scavenging capacities in aqueous extracts ranging between 2869 and 4312 mg gallic acid equivalents/kg legume and 24.42 and 38.20 mmol Trolox equivalents/kg legume, respectively. However, the free radical scavenging capacity of lentil and chickpea protein extracts, range between 110 and 185 mmol Trolox/kg protein and 58 and 144 mmol Trolox/kg protein, respectively, clearly showed the higher free radical scavenging capacity of lentil proteins than chickpea proteins.Protein extracts of chickpeas and lentils showed considerable emulsifying and foaming capacities in almost at the same range, but emulsions and foams formed by chickpea proteins are more stable than those of lentil proteins. The lentil protein extracts are highly soluble and showed poor water absorption and gelling characteristics. In contrast, chickpea protein extracts showed moderate water absorption and gelling capacity.Chickpea protein extracts are also good oil absorbers with almost 1.5 to 2 fold better oil adsorption capacity than lentil protein extracts. Thus, chickpea proteins are suggested as soy and whey protein alternatives for functional proteins used in the food, drug and cosmetics industries. Considering functional properties of proteins for different cultivars, the outstanding Turkish chickpea cultivars are Gökçe and Cevdetbey, while the outstanding Turkish lentil cultivar is Alidayı. Variations in the functional properties of protein suggest the diversity of genes in chickpeas and lentils responsible for these properties. Thus, this study showed the possibility of improving functional properties of chickpeas and lentils by breeding programs.Master Thesis Characterization of Peppers for Antioxidant Content and Virus Resistance(Izmir Institute of Technology, 2008) Keçeli, Mehmet Ali; Doğanlar, SamiIn the first part of this study, total water soluble antioxidant activity, phenolic compounds and vitamin C content of 29 Turkish and 14 non-Turkish pepper cultivars were determined. Significant trait diversity was found in the cultivars with the most variation (7.4-fold) seen for total antioxidant capacity which ranged from 2565 to 18957 .mol Trolox/kg. Vitamin C content for the peppers ranged from 522 to 1631 mg/kg, a 3.1-fold difference, while total phenolic content for the pepper cultivars ranged from 607 to 2724 mg/kg, a 4.5-fold difference. A strong correlation between total antioxidant capacity and phenolic content (r . 0.71) was also seen. Significant variation for antioxidant content in Turkish germplasm indicates that this material can be used for improvement and genetic mapping of nutritional content in pepper. In the second part of this study, amplified fragment length polymorphism (AFLP), cleaved amplified polymorphism (CAPs) and simple sequence repeat (SSR) markers were used to map gene(s) for cucumber mosaic virus resistance. The mapping was conducted using a F2 population derived from a cross between Capsicum annuum cv. Jupiter (susceptible) X C. frutescens (resistant). The F2 population, consisting of 76 individuals, was screened with 13 AFLP primer pairs, 60 CAPs markers and 30 SSR markers to detect markers possibly linked to CMV resistance gene(s). As a result, 7 QTL were found which are related with resistance to CMV in pepper. This will provide pepper breeders an opportunity to use these markers for marker-assisted selection for CMV resistance in pepper.Master Thesis Production of Proanthocyanidins From Grape Seed(Izmir Institute of Technology, 2003) Altıok, Evren; Ülkü, Semra; Ülkü, SemraProanthocyanidin is a potent antioxidant that is why it directly affects many important diseases such as coronary heart disease, cholesterol etc. Thus, proanthocyanidin is one of the important dietary supplements, which is mainly found in grape seeds. In this study the extraction of this valuable antioxidant from grape seeds was studied. For the extraction of proanthocyanidins, different solvents such as ethanol, methanol, acetone and their aqueous forms were used. The maximum extraction yield was achieved after 24 h at room temperature. It was observed that 70% aqueous acetone was the best solvent with the highest yield of 17.5%. Yield of proanthocyanidin extracted with 70% aqueous acetone was 3 times greater than proanthocyanidins extracted with other solvents. The extract was freeze dried to obtain the product as powdered form. To compare the product with commercial ones HPLC chromatograms and FTIR spectra were taken and similar spectra were obtained. With HPLC, monomers of proanthocyanidins; (+)-catechin and (-)- epicatechin were determined. (+)-catechin was observed at 17.2 min as 3.06%w/w. Also, (-)-epicatechin was observed at 42.8 min as 1.99%w/w. Most of the drying methods are performed at high temperatures which may result negative effects on proanthocyanidin`s antioxidant capacity. Even the applications at low temperatures in case of freeze-drying have some disadvantages e.g. the process takes a long time, it is expensive and has some difficulties. Therefore as an alternative to other concentration and drying techniques, adsorption process was thought to be a promising technique. Although adsorption of proanthocyanidins on zeolites were not obtained, removal of excess water from the extracts can be achieved by using zeolites. This would possess as a promising technique for the concentration of the end productThe antioxidant capacities of proanthocyanidins from the grape seed extracts were also determined. Proanthocyanidin has an antioxidant capacity with 57 TEAC value, which is more than synthetic antioxidants; BHT, BHA, TBHQ and PG, 6.66, 0.593, 1.168 and 12.62 TEAC respectively. .Master Thesis Screening of Some Plant Species for Their Total Antioxidant and Antimicrobial Activities(Izmir Institute of Technology, 2008) Kaçar, Diren; Bayraktar, OğuzIn this study aqueous/ethanol extracts of 42 plant species collected from same geographic region (Karaburun/İzmir) were screened for their relative total phenol contents, total antioxidant and antibacterial activities. In the first part of the study, Folin- ciocalteu assay and PCL (Photochemiluminescence) method were performed to detect the total phenol contents and total antioxidant activities of extracts, respectively.It was detected that the Hypericum empetrifolium had the highest activities for both water soluble and lipid soluble antioxidants and Sarcopterium spinosum has the highest result for total phenol assay as 635.26 GAEqmg/g sample.In order to detect the antibacterial activities of extracts a preliminary screening study was performed by using disc diffusion method. Out of the 42 plant species tested, 26 species exhibited antibacterial activities by inhibiting one or more microorganisms.Microdilution assays by 96 well plates were applied for the most active species to find out their minimum inhibition concentrations (MICs). The most promising plant species in the study, having the antibacterial activities were determined as H. empetrifolium, P.terebinthus, Arbutus unedo, and C. parviflorus.In this study there is a clear relationship between the analysis results and S.spinosum is one of the most noteworthy species in this study showing the highest total phenol content and important biological activities which has never been examined scientifically before. In that manner this study also presents new potential species that can be used as natural raw materials in some related industries.Master Thesis Adsorption of Olive Leaf Antioxidants on Silk Fibroin(Izmir Institute of Technology, 2006) Bayçın Hızal, Deniz; Bayraktar, OğuzThis study focused on producing protein based functional food with antioxidative and antimicrobial properties by adsorption of olive leaf antioxidants on silk fibroin. In accordance with this aim, extraction and adsorption of two most abundant polyphenols in olive leaves, oleuropein and rutin were studied. Furthermore, desorption studies were performed to increase the purity of polyphenols.In this study, effect of various parameters on extraction and adsorption were investigated by HPLC and antioxidant analyses. The adsorption isotherms of oleuropein and rutin were plotted at different temperatures, pH values and solid-liquid ratios. After adsorption, the adsorbed polyphenols on silk fibroin was subjected to SEM, FTIR, color, antioxidant and antimicrobial analyses to observe the changes in the silk fibroin.The experimental data of adsorption isotherms were well-fitted to Langmuir model. The maximum adsorption capacity was determined as 108 mg oleuropein/g silk fibroin and 21 mg rutin/g silk fibroin. In desorption process, 81% of rutin and 85 % of oleuropein were removed from the adsorbent surface in 70 % aqueous ethanol solution.After adsorption of oleuropein and rutin, the antioxidant capacity of silk fibroin increased from 1.93 mmol TEAC/g to 3.61 mmol TEAC/g. Silk fibroin also gained antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae after adsorption of olive leaf antioxidants. Desorbed polyphenols exhibited higher antioxidant capacity than the same amount of olive leaf extract due to the increase in the purity of oleuropein and rutin after desorption.Consequently, silk fibroin is a promising protein for the production of functional food or dietary supplements and for the purification of oleuropein and rutin.