Ultrasound assisted extraction of lipids and antioxidants from wheat germ

Melikoğlu, Mehmet
The aim of this thesis work was to extract lipids and antioxidants from wheat germ using an ultrasonic bath. Alternative solvents: Ethanol, isopropanol and acetone were used for the extraction purposes and for the fat content determination hexane was used. Alternative solvents dissolve wax, phospholipids and some other proteins because of their polar nature which increased the yield. Since waxes and some proteins can be added to the soaps and creams which were made from carrier oils, obtaining these substances together with the oil in the extract was very useful. For isopropanol a linear relation was found between the extract ratio and ultrasonication time. The highest extract ratios were achieved with ethanol. For 30 minutes of ultrasonication 0.10 g extract / g germ was obtained. After the extraction in order to enhance the phase separation between the solid phase (germ and other solids) and the extract phase, combinations of centrifugation, storage in the refrigerator and decantation were tested. The technique involving storage the extracts in the refrigerator for 24 hours and centrifugation at 2800 rpm for 20 minutes gave the second highest yield but the best phase separation. Ethanol extracts from both roasted and nonroasted wheat germs were characterized in terms of their total polyphenol contents. For non roasted wheat germs total polyphenol contents of 200 mg gallic acid / L solution and for roasted wheat germs an average of 170 mg gallic acid / L solution were obtained for 30 minutes of ultrasonic extraction. For nonroasted wheat germs weak but significant linear relations were found between total polyphenol contents of the extracts and ultrasonication time.


Hydrogen production by microorganisms in solar bioreactor
Uyar, Başar; Eroğlu, İnci; Department of Biotechnology (2008)
The main objective of this study is exploring the parameters affecting photobiological hydrogen production and developing anaerobic photobioreactor for efficient photofermentative hydrogen production from organic acids in outdoor conditions. Rhodobacter capsulatus and Rhodobacter sphaeroides strains were used as microorganisms. EU project “Hyvolution” targets to combine thermophilic fermentation with photofermentation for the conversion of biomass to hydrogen. In this study, the effluent obtained by dark fe...
Hemicellulose based biodegradable film production
Göksu, Emel Iraz; Bakır, Ufuk; Department of Chemical Engineering (2005)
Xylan was extracted from cotton waste, characterized by DSC and TGA analysis and used in biodegradable film production. Pure cotton waste xylan did not form film. The presence of an unknown compound, as an impurity, yielded composite films. The unknown compound was determined as a phenolic compound, and most probably lignin, by using DSC and TGA analysis and Folin-Ciocalteau method. The effects of xylan concentration of the film forming solutions, glycerol (plasticizer) and gluten additions on thickness, me...
Investigating the anticarcinogenic role of salix aegyptiaca l. in colorectal carcinoma
Enayat, Shabnam; Banerjee, Sreeparna; Department of Biology (2009)
In this study, extracts from bark, leaves and catkins of Salix aegyptiaca L. were investigated for their antioxidant content by 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) free radical quenching assay, total phenolic and total flavonoid assays. The highest antioxidant activity (19 ug/ml IC50 for inhibition of DPPH radical activity), total phenolic content (212 mg gallic acid equivalents/g of dried extract) and total flavonoid (479 mg catechin equivalents/g of dried extract) was observed in the ethanolic ex...
Optimization of selection conditions and agrobacterium mediated transformation of chickpea (cicer arietinum L. cv. Gökçe)
Öz, M. Tufan; Öktem, Hüseyin Avni; Department of Biotechnology (2005)
The objective of this study was to optimize an efficient selection system and Agrobacterium mediated transformation of chickpea (Cicer arietinum L.). Cotyledonary node explants of Turkish chickpea cultivar Gökçe were used to determine the effects of selective agents, two antibiotics (Kanamycin, Hygromycin) and two herbicides (PPT, Glyphosate) as well as four antibiotics (Augmentin, Carbenicillin, Cefotaxime, Timentin) for eliminating Agrobacterium on multiple shoot and root induction. Selective agents and a...
In vitro induction of growth and development of common juniper(Juniperus communis L.) from shoot and bud explants
Koçer, Zeynep Ahsen; Kaya, Zeki; Department of Biotechnology (2005)
The objective of the study was to investigate the optimum conditions for in vitro regeneration of common juniper (Juniperus communis L.) by using indirect organogenesis approach. Throughout the study; callus induction, organogenesis, improved organogenesis and root induction experiments were performed sequentially. It was found that explant position, genotype, gender, treatments and sampling time had significant effects on callus induction rate in common juniper. The results of treatments indicated that IBA...
Citation Formats
M. Melikoğlu, “Ultrasound assisted extraction of lipids and antioxidants from wheat germ,” M.S. - Master of Science, Middle East Technical University, 2005.