Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Formulation and characterization of clove and thyme oil emulsions
Download
12626114.pdf
Date
2021-2-10
Author
Tonyalı Karslı, Gökcem
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
450
views
825
downloads
Cite This
Essential oils are natural aromatic compounds obtained from various parts of plants such as flowers, bark, stems, and roots. They have been used in medicine, cosmetics, and food science since ancient times due to their antimicrobial, antioxidant, and therapeutic properties. Especially in recent times, negative impressions about synthetic additives have increased the use of essential oils in the food industry. The aim of this study is to produce and characterize emulsions with thyme and clove essential oils as natural additives. Emulsification was important to have stable systems since essential oils are highly volatile and aromatic droplets. Through the emulsions, excessive consumption of essential oils was avoided, and long-term stable emulsion systems were obtained while aiming to have same effects. Emulsions were prepared by using essential oil as the dispersed phase and water-surfactant mixture as the continuous phase. As the surfactant, Tween 80 was used. In total, four emulsions were formulated with 2% and 4% of each essential oil by using microfluidization as the homogenization method. Droplet sizes, polydispersity index and zeta potential values of emulsions were measured, and their effects on stability were investigated. The morphology of the emulsions was analyzed by TEM. Antioxidant capacity and total phenolic content were determined on both pure essential oils and emulsions. In addition, TD-NMR analysis was conducted to measure the relaxation times of T1 and T2 of both pure oils and emulsions. As a result of droplet size measurements, emulsions with smaller droplet size were obtained with clove oil emulsions. The reason was thought to be the good interaction between clove oil and Tween 80. However, while thyme oil emulsions were stable for three months, de-stability started in clove oil emulsions soon after homogenization. The mechanism of instability was thought to be Ostwald ripening, which is quite common in emulsions containing essential oils. Stability results were parallel to the change of polydispersity index over time. However, no correlation was found between zeta potential and stability. Considering antioxidant experiments, clove oil was found to be a more powerful antioxidant than thyme oil. It has also been stated that clove oil emulsions have more antioxidant capacity than thyme oil emulsions. The total amount of phenolic content gave a positive correlation with the antioxidant capacity results. In particular, a stronger correlation was found with clove oil.
Subject Keywords
Emulsions
,
Essential Oils
,
Droplet Size
,
Antioxidant Capacity
,
Stability
URI
https://hdl.handle.net/11511/89564
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Synthesis and characterization of multi-hollow opaque polymer pigments
Asmaoglu, Serdar; Gündüz, Güngör; MAVİŞ, BORA; Colak, Uner (Wiley, 2016-08-05)
A new generation multihollow opaque polymer pigment was synthesized by suspension polymerization of water-in-oil-in-water emulsion method, where methyl methacrylate and ethylene glycol dimethacrylate monomer mixture was used as oil phase. The effects of surfactant and cosurfactant composition in terms of hydrophilic/lipophilic balance on the stability of the water-in-oil emulsion and the size of water droplets were studied. Low droplet sizes and the optimum stability were obtained with Span 80&Tween 80 surf...
Synthesis and charaterization of single hollow opaque polymer pigments
Karakaya, Ekin; Gündüz, Güngör; Maviş, Bora; Department of Chemical Engineering (2013)
In the present work opaque polymer pigments with single hollow structure were synthesized by osmotic swelling method. The hollow pigment is composed of an outer shell and an inner void space which can be filled with air or water. The osmotic swelling process involves synthesizing of a core polymer containing carboxylic acid group on the backbone, and encapsulating it with another polymer which functions as shell. The swelling of the polymer is provided by neutralization of the core with a base. Methyl metha...
Synthesis of conducting polysiloxane-polypyrrole graft copolymers
Gunaydin, O; Toppare, Levent Kamil; Yagci, Y; Harabagiu, V; Pintela, M; Simionescu, BC (Springer Science and Business Media LLC, 2002-02-01)
Polysiloxane-polypyrrole graft copolymers have been synthesized by a series of chemical reactions and subsequent electropolymerization. First, the hydrosilation of 4-vinyl aniline by dimethyl-methylhydrosiloxane copolymer gave the corresponding aminophenyl functional polydimethylsiloxane (PDMS-NH2). The side chain pyrrole functionalized. polysiloxanes were then prepared by the reaction of PDMS-NH2 with glycidylpyrrole. Finally, the synthesis of graft copolymers of polysiloxane and pyrrole has been achieved ...
Biodegradation of the Allelopathic Chemical Pterostilbene by a Sphingobium sp. Strain from the Peanut Rhizosphere
Yu, Ri-Qing; Kurt, Zöhre; He, Fei; Spain, Jim C. (American Society for Microbiology, 2019-03-01)
Many plants produce allelopathic chemicals, such as stilbenes, to inhibit pathogenic fungi. The degradation of allelopathic compounds by bacteria associated with the plants would limit their effectiveness, but little is known about the extent of biodegradation or the bacteria involved. Screening of tissues and rhizosphere of peanut (Arachis hypogaea) plants revealed substantial enrichment of bacteria able to grow on resveratrol and pterostilbene, the most common stilbenes produced by the plants. Investigati...
Identification and Quantification of Phenolic Components of Rosa heckeliana Tratt Roots
Çoruh, Nursen (2015-03-16)
Medicinal plants reveal their therapeutic effects due to the high amount of phenolic compounds confined abundantly in roots, fruits, leaves, and flowers. Rosa heckeliana Tratt, as a member of Rosa, was recently discovered as one of the important medicinal plants used in folk medicine. In this study, the therapeutically notable Rosa heckeliana was selected for the analysis of important phenolic components particularly confined in the roots. The roots were first extracted in methanol, then phenolic constituen...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
G. Tonyalı Karslı, “Formulation and characterization of clove and thyme oil emulsions,” M.S. - Master of Science, Middle East Technical University, 2021.