The lecture presents the basics of lipid oxidation in emulsions and the reasons for the oxidative instability of the emulsion, offers the ways for the controlling of lipid oxidation in emulsions and highlights factors that determine the effectiveness of antioxidants in emulsions. These include, in addition to antioxidants' radical scavenging, their partition properties and the properties of the emulsions. The lecture includes, in addition to the theoretical bases, also the results of our research related to this topic.
B.04 Guest lecture
COBISS.SI-ID: 4432504We investigated the influence of carrier systems in commercially formulations of water soluble CoQ10 on structural changes of model lipid membranes composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and mixture of phosphatidylcholine and sphingomyelin (2.4:1) after contact with them. Structural changes in the membrane were measured by the combination of fluorescence spectroscopy, electron paramagnetic resonance and differential scanning calorimetry. Two fluorophors and two spin probes were used to monitor membrane characteristics close to water-lipid interface and in the middle of the bilayer of model lipid membranes. Results show that different water soluble carrier systems (glycerol in combination with polyglycerol fatty acid ester, soy lecithin and triglyceride of fatty acid; pregelatinized starch combined with gum arabic and lactose; starch sodium octenylsuccinate with dextrin and glycerol; β-cyclodextrin) facilitate perturbation of CoQ10 into lipid membrane where an increase in lipid order parameter is observed. In addition water soluble CoQ10 formulations allowed better protection from oxidation in liposome solution, and shoved better antioxidative potential in water and ethanol solution, measured as inhibition of ABTS•+ radical. With the exception of carriers present in emulsified formulation of CoQ10 (Sample A, where glycerol, soy lecithin and PGE are present as carriers), the carriers present in other samples did not have a significant effect on membrane fluidity
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 4399736The knotweed represents an invasive plant, which when uncontrolled, creates a high, compact growth which suppresses the original plants and in this way it lessens the biological diversity everywhere it penetrates. On the other hand these invasive plants contain lots of different antioxidants that still require identification and quantification. Therefore, for the purpose of this study, water, ethanol and butanol extracts of five different plant tissues (young leaves, old leaves, rhizomes, stalks, and flowers) from three different European knotweed species (Fallopia japonica, Fallopia sachalinensis and Fallopia x bohemica) were prepared and analysed by four different methods (chemiluminescence, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), Folin–Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙)) for evaluation of antioxidant capacity (AOC). Regarding methods, chemiluminescence assay correlates strongly with ABTS assay in all extraction media. The correlation between chemiluminescence assay and Folin–Ciocalteu assay was on the other hand strong only in the case of water and ethanol extracts, and with only a moderate correlation in the butanol extracts. Similarly, DPPH˙ assay is strongly correlated with chemiluminescence assay in water and ethanol extracts, whereas only weak correlation was determined in butanol extracts. Regarding overall AOC, all knotweed species were found to be a rich source of antioxidants, particularly F. sachalinensis. The most powerful antioxidants were extracted by ethanol and the weakest by butanol. The antioxidants are the most abundantly present in the flowers, whereas the stalks contain the lowest amount of them. Our study showed that antioxidants are synthesized during spring and early summer and they start to slowly degrade during late summer and autumn.
B.04 Guest lecture
COBISS.SI-ID: 4398712Day of biomolecular sciences is a dynamic and versatile event. The main purpose of the all-day event, which took place on 23. 9. 2014 at Biotechnical Faculty, was the promotion of life sciences for future undergraduate and doctoral students. Participants were also informed by the views of experts from industry and individuals who have established biotechnological company. The event was attended by more than 100 participants. Day of biomolecular sciences (http://www.biomolekularec.si/ ) is one of the few events where secondary school students, university students and recognized researchers side by side represent their own research work.
B.06 Other
COBISS.SI-ID: 275596288