(-)-Epigallocatechin gallate (EGCG) was encapsulated into liposomes in order to protect it against adverse environmental conditions. The liposomes were further incorporated into alginate and chitosan microparticles. The stability of free and encapsulated EGCG in all three systems was evaluated at different pH values and in fruit nectar. Furthermore, the interactions between EGCG and the compounds of the microparticles were studied using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). All three encapsulation systems showed high encapsulation efficiency ()97%) and sustained release; in 14 days, no more than 15% of EGCG was released. The encapsulation systems successfully protected EGCG against degradation at alkaline pH. For non-encapsulated EGCG, )70% was degraded after 14 days, while there was no significant degradation of encapsulated EGCG in these three systems. In fruit nectar, )30% of non-encapsulated EGCG was degraded in 14 days, while only 6% of EGCG encapsulated into liposomes or chitosan microparticles reinforced with liposomes was degraded at that time. The DSC and FTIR analyses showed that the main interactions occurred between the liposomes and the EGCG. This study demonstrates that liposomes as well as alginate and chitosan microparticles reinforced with liposomes have the potential to enhance EGCG stability in food products during storage.
COBISS.SI-ID: 4633976
Sprouting and malting of buckwheat, results in the induction of biosynthesis of polyphenols, predominantly isoorientin, orientin, and isovitexin. Only a minor relative increase was observed for the most abundant phenolic compound, rutin. A considerable increase in total phenolic compounds and higher antioxidant activity were observed after germination, whereas kilning resulted in minor decreased of total phenolic compounds and antioxidant activity. Changes in the composition of the phenolic compounds and increased antioxidant content indicate that buckwheat malt can be used as a food rich in antioxidants.
COBISS.SI-ID: 4649592
Aminopeptidases execute and regulate the total and specifically limited protein breakdown involved in plant physiology. We have identified, in leaves of common bean, five aminopeptidases whose levels of activity changed when three week old plants were subjected to drought. Three metallo and two serine aminopeptidases were first identified and then isolated using ion exchange chromatography of leaf extracts. Their apparent molecular weights range from 37 kDa to 80 kDa. Levels of activity of individual aminopeptidases are shown to depend on the age of leaves. Drought initiated an almost general increase of their activities, although to different extents, meaning that it is necessary to investigate the effects of drought separately in leaves of different ages.
COBISS.SI-ID: 29951271
This research studied the possible relation between oil properties and structure and physical properties of saturated monoglyceride (MG)-based organogels. To this aim different oils (castor, cod liver, corn, extra virgin olive, flax-seed, peanut and sunflower oil, and mixture of medium chain triacylglycerols (MCT)) were used to prepare organogels by adding 10% w/w of monoglycerides. The fatty acid composition, viscosity, and dielectric properties of oils were measured. Then, organogels were characterized for crystallization induction time, dielectric properties, firmness, rheological behavior, thermal properties, crystal morphology by polarized light microscopy, and crystal polymorphism by synchrotron X-ray diffraction (XRD) analysis. Results acquired showed that the addition of MG in different types of oils led to the formation of organogels with different properties. In all cases, β polymorph formed in the system irrespective of oil type. Regarding oils containing long chain fatty acids, gel firmness, and other structural parameters correlated well with the dielectric constant and/or viscosity of oils: increasing oil viscosity or decreasing oil dielectric constant, firmness and rheological parameters linearly increased. On the other hand, these correlations cannot be found including in the statistical analysis castor oil or MCT, probably due to the higher ability of these oils to make dipole–dipole rotation as well as the higher solubility of MG in castor oil. Practical applications: Oil gelation (organogelation) is a relative novel strategy to convert liquid oils into structured systems that has attracted food scientists and industry managers looking for solutions to reduce saturated/trans fats, deliver bioactive molecules, and minimize oil migration in foods. Results acquired in this research highlight that the choice of oil to be structured by means of saturated monoglycerides could affect the final gel structure. These findings could be useful in the attempt to applied organogels in different food products having different physical properties.
COBISS.SI-ID: 4672632
We investigated the influence of carrier systems for different commercially available water-soluble formulations for coenzyme Q10 on structural changes of model lipid. Structural changes in the membranes were measured using fluorescence anisotropy, electron paramagnetic resonance, and differential scanning calorimetry. Two fluorophores and two spin probes were used to monitor membrane characteristics close to the water-lipid interface and in the middle of the bilayer of the model lipid membranes. Different water-soluble carrier systems were tested. These data show that different systems can facilitate penetration of CoQ10 in the lipid membranes. In addition water soluble CoQ10 formulations allowed better protection from oxidation in liposome solution, and shoved better antioxidative potential in water and ethanol solution.
COBISS.SI-ID: 4571256