No abstract

No abstract

No abstract

Please cite this article as: Lević, S., Pajić Lijaković, I., Đorđević, V., Rac, V., Rakić, V., Šolević Knudsen, T., Pavlović, V., Bugarski, B., Nedović, V., Characterization of sodium alginate/D-limonene emulsions and respective calcium alginate/D-limonene beads produced by electrostatic extrusion, Food Hydrocolloids (2014), Abstract 17 18 In this study, calcium alginate beads immobilizing D-limonene (solid systems) have been 19 manufactured starting from emulsions of this flavor in sodium alginate (liquid systems). The 20 effects of alginate concentration (0.02 and 0.03 g/mL) and flavor content (5 and 10 %w/w) on 21 viscosity, conductivity and stability of emulsions were investigated. The flavor droplets in 22 emulsions are bigger as polymer solution is more concentrated and contains more of the flavour.23When emulsions have been subjected to electrostatic extrusion and upon Na + -Ca 2+ ion exchange, 24 smaller (~960 to ~1450 µm) and less spherical beads were obtained (sphericity factor 0.003 to 25 M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 2 0.21) compared to beads produced by simple dripping technique (without electrostatic field). 26When wet beads were air dried, they shrunk less if they had higher content of the flavour. Novel 27 mathematical model describing swelling kinetics of dried beads is developed. In this work, D-28 limonene was efficiently immobilized within Ca-alginate beads (immobilization efficiency ~50 29 to ~77%) and its thermal stability was confirmed by TG/MS analysis. 30 31

The surface modification of nanocrystalline TiO2 particles (45 Å) with catecholate-type ligands having different electron donating/electron withdrawing substituent groups, specifically 3-methylcatechol, 4-methylcatechol, 3-methoxycatechol, 3,4-dihydroxybenzaldehyde and 4-nitrocatechol, was found to alter the optical properties of nanoparticles in a similar way to catechol. The formation of the inner-sphere charge-transfer (CT) complexes results in a red shift of the semiconductor absorption compared to unmodified nanocrystallites and a reduction of the effective band gap, being slightly less pronounced in the case of electron withdrawing substituents. The investigated ligands have the optimal geometry for binding to surface Ti atoms, resulting in ring coordination complexes of the catecholate type (binuclear bidentate binding-bridging) thus restoring six-coordinated octahedral geometry of surface Ti atoms. From the absorption measurements (Benesi-Hildebrand plot), the stability constants in methanol/water = 90/10 solutions at pH 2 in the order of 10(3) M(-1) have been determined. The binding structures were investigated by using FTIR spectroscopy. Thermal stability of CT-complexes was investigated by using TG/DSC/MS analysis. Quantum chemical calculations on model systems using density functional theory (DFT) were performed to obtain the vibrational frequencies of charge transfer complexes, and the calculated values were compared with the experimental data.