Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Microbiological Characterization of 'hurma Olives Grown in Karaburun Peninsula(Izmir Institute of Technology, 2013) Karslı, Gözde Seval; Baysal, Ayşe Handan; Baysal, Ayşe Handan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyErkence variety olive (Olea europea L.) cultivar growing in the Aegean Region of Turkey is a naturally black olive. Debittered Erkence variety called "Hurma" olive is an unusual olive type which is characterized by the sweet taste of its fruit. This olive which is grown mainly in Karaburun Peninsula differs from other varieties since it ripens on the tree losing its bitterness caused by phenolic compounds especially oleuropein. Thus, Hurma olives can be directly consumed from the tree without a further debittering process to make them edible. Total aerobic mesophilic microorganisms, lactic acid bacteria (LAB), Enterobacteriacaae, Pseudomonadaceae, Staphylococcaceae-Micrococcaceae, moulds and yeasts were enumerated in the olive drupes, leaves and orchards' air of Erkence and Gemlik cultivars during the maturation period. Moreover, bacterial microflora of Hurma olive fruit, leaf and orchards' air were characterized in terms of DNA sequencing. Microbial loads of naturally debittered "Hurma" olive were higher when compared with Gemlik olive's and non-debittered Erkence variety olive's. But no Pseudomonadaceae, Staphylococcaceae-Micrococcaceae and LAB were detected in all samples. Bacterial microflora genera of Hurma olive comprised of Bacillus, Pantoea, Acinetobacter and Pseudomonas while the other samples have also similar bacterial genera. The common genus found in all samples was Bacillus. Besides, more diversified genera were obtained from phylloplane and air microflora of Erkence variety olive orchard was substantially similar to bacterial phylloplane of leaf. This is the first study about microbiological characterization of Hurma olive type and will lead up to new studies about it.Master Thesis Chemical Characterization of 'hurma Olive Grown in Karaburun Peninsula(Izmir Institute of Technology, 2013) Aktaş, Ayşe Burcu; Özen, Fatma Banu; Özen, Fatma Banu; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyOlive type, mostly Erkence, grown in nearby area around Karaburun peninsula of Izmir-Turkey, goes through a natural debittering phase on the tree during its ripening. This olive is known by the name of Hurma and loses its bitter taste while still on the tree and can be consumed directly at the end of this natural process. The aim of this study is to investigate the changes in the chemical composition of Hurma, Erkence and Gemlik olives throughout their maturation period and to determine some chemical compositional differences between Hurma and other types of olives to obtain more insight about the natural debittering phenomena. For this purpose, the chemical parameters measured are pH, water activity, total fat amount, fatty acids, sugar and organic acid amounts, total phenol content and phenol profile. All analyses were performed for two harvest years. Data were analyzed by ANOVA and principal component analysis (PCA) to investigate the differences regarding the olive types, ripening period and harvest year. Total phenol content and generally concentration of individual phenolic compounds of Hurma olive were lower than Erkence and Gemlik olives. Both fatty acid and phenol profiles allowed a differentiation with respect to type and also harvest year according to PCA while organic acid and sugars provided a separation only in terms of harvest year.Master Thesis Purification of Polyphenolic Compounds From Crude Olive Leaf Extract(Izmir Institute of Technology, 2011) Karakaya, Alihan; Bayraktar, Oğuz; Bayraktar, Oğuz; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyStudy was carried out to investigate the adsorption characteristics of olive leaf extract on the macroporous adsorption resins and the efficiency of the adsorption column for the separation and purification of oleuropein and rutin from the crude plant extract. Both static and dynamic experiments were performed. In static studies, the performances of three macroporous Amberlite resins namely XAD4, XAD 16 and XAD7HP for the adsorption of polyphenols were evaluated. XAD7HP was chosen as an adsorbent for further adsorption study. XAD7HP was selected for the studies of isotherms, kinetics of adsorption. In conventional alcohol extraction, crude feedstock is mixed with solvent which is alcohol for most cases, and then extract is distilled to remove ethanol. This process ends with a certain amount of residual ethanol because of complication in separation process for ethanol and water makes an azeotropic binary system. The results showed that adsorption capacity of an alcoholic solution with 10 % ethanol content is better than aqueous solution which contained no ethanol. In dynamic studies, the adsorption and desorption experiments were carried out on a glass column packed with XAD7HP resin. The flow velocity 122 cm/h operated as a fixed bed while operation was in an expanded bed mode at 367 cm/h and 611 cm/h, respectively. The effectiveness of the packed bed adsorption and the fluidized bed adsorption were compared. The results show the breakthrough occurred earlier when the feed flow velocity increased. In the elution step, elution program with 2,000 ml for 0 %, 4,000 ml for 40 % and 3,000 ml for 90 % aqueous ethanol was used to achieve an efficient separation. Total phenol content and antioxidant capacity of olive leaf crude extract and effluent fractions were analyzed in order to find the difference between before and after separation. Consequently, fluidized bed adsorption is a promising alternative for the packed bed adsorption in order to isolate oleuropein and rutin from the olive leaf extract.