3. Biotechnological applications based on biocompatible components - Olive oil
We recently developed an interesting type of microemulsions: systems with biocompatible ingredients such as olive oil or limonene. The obtained systems were structurally characterized using Dynamic light scattering, fluorescence, EPR and conductivity. They offer a suitable environment for the entrapment of various active components with applications to the Food, cosmetics and pharmaceutical industries.
Virgin olive oil itself can be considered as a colloidal dispersion of various amphiphiles and hydrophilic compounds (minor components) in a relatively non polar triglyceride environment. The project aims at characterizing the structure of the dispersed molecular assemblies in relation to the stability of the product, as well as analysing the function of some antioxidant and protein compounds. For this model microemulsions based on olive oil and used to encapsulate enzymes that are involved in oxidation processes in olive oil in presence of antioxidants. The technique of EPR was applied to determine the production of free radicals either directly or through the use of spin-traps such as PBN or DMPO.
In parallel we developed an accurate and fast technique for the assessment of the antioxidant activity and the free radical scavenging capacity using EPR.
Á. Light microscopy of olive oil emulsion formed after extraction with 50 mM Tris-HCl (pH 9.0).
B. Light microscopy of olive oil emulsion, extracted with 50 mM Tris-HCl (pH 7.5), after papain treatment (0.05 mg/ml) for 10 min.
V. Papadimitriou, E. D.Tzika, S. Pispas, T.G. Sotiroudis, A. Xenakis (2011) "Microemulsions based on virgin olive oil: a model biomimetic system for studying native oxidative enzymatic activities" Colloids Surfaces.A: Physichochemical & Engineerinig Aspects, 382, 232-237E.
D. Tzika, M. Christoforou, S. Pispas, M. Zervou, V. Papadimitriou, T. G. Sotiroudis, E. Leontidis, A. Xenakis (2011) "Influence of nanoreactor environment and substrate location on the activity of horseradish peroxidase in olive oil-based w/o microemulsions" Langmuir, 27, 2692-2700.
A. Xenakis, V. Papadimitriou, T.G. Sotiroudis (2010) "Colloidal structures in natural oils" Curr.Opinion Colloid Interface Sci. 15, 55-60E.
D.Tzika, T.G. Sotiroudis, V.Papadimitriou, A.Xenakis (2008) "Characterization of peroxidase activity in oil producing koroneiki olives" European Food Research and Technology., In press
V. Papadimitriou, T.G. Sotiroudis, A. Xenakis, (2007) Olive oil microemulsions: enzymatic activities and structural characteristics, Langmuir, 23, 2071-7.
V. Papadimitriou, T.G. Sotiroudis, A. Xenakis, N. Sofikiti, V. Stavyiannoudaki, N.A. Chaniotakis (2006) "Oxidative stability and radical scavenging activity of extra virgin olive oils by using Electron Paramagnetic Resonance spectroscopy", Anal.Chim.Acta, 573-574, 453-458.
T.G. Sotiroudis, G.T. Sotiroudis, N. Varkas and A. Xenakis (2005) "Interfacial properties of virgin olive oil-in-water emulsions stabilized by endogenous amphiphiles" J.Am.Oil Chem. Soc. 82, 415-420.
