This study is focused on the novel approaches to enhance the inactivation of the Gram (-) food pathogen Salmonella enterica and harmful molds in vitro and on the surface of strawberries using the chlorophyllin-chitosan complex. Salmonella enterica (∼1 × 10(7) CFU mL(-1)) was incubated with chlorophyllin 1.5 × 10(-5) M (Chl, food additive), chitosan 0.1% (CHS, food supplement) or the chlorophyllin-chitosan complex (1.5 × 10(-5) M Chl-0.1% CHS) and illuminated with visible light (λ = 405 nm, light dose 38 J cm(-2)) in vitro. Chlorophyllin (Chl)-based photosensitization inactivated Salmonella just by 1.8 log. Chitosan (CHS) alone incubated for 2 h with Salmonella reduced viability 2.15 log, whereas photoactivated Chl-CHS diminished bacterial viability by 7 log. SEM images indicate that the Chl-CHS complex under these experimental conditions covered the entire bacterial surface. Significant cell membrane disintegration was the main lethal injury induced in Gram (-) bacteria by this treatment. Analysis of strawberry decontamination from surface-inoculated Salmonella indicated that photoactivated Chl-CHS (1.5 × 10(-5) M Chl-0.1% CHS, 30 min incubation, light dose 38 J cm(-2)) coatings diminished the pathogen population on the surface of strawberries by 2.2 log. Decontamination of strawberries from naturally distributed yeasts/molds revealed that chitosan alone reduced the population of yeasts/molds just by 0.4 log, Chl-based photosensitization just by 0.9 log, whereas photoactivated Chl-CHS coatings reduced yeasts/molds on the surface of strawberries by 1.4 log. Electron paramagnetic resonance spectroscopy confirmed that no additional photosensitization-induced free radicals have been found in the strawberry matrix. Visual quality (color, texture) of the treated strawberries was not affected either. In conclusion, photoactive Chl-CHS exhibited strong antimicrobial action against more resistant to photosensitization Gram (-) Salmonella enterica in comparison with Gram (+) bacteria in vitro. It reduced significantly the viability of strawberry surface-attached yeasts/molds and inoculated Salmonella without any negative impact on the visual quality of berries. Experimental data support the idea that photoactivated Chl-CHS can be a useful tool for the future development of edible photoactive antimicrobial coatings which can preserve strawberries and prolong their shelf-life according to requirements of "clean green technology".

The room temperature ionic liquid (RTIL) 1-decyl-3-methyl-imidazolium bromide [C10mim][Br], dissolved in water, was studied using 1 H and 13 C NMR spectroscopy. The manifestation of phase transitions and fine features of molecular motion in NMR spectra upon changing temperature and composition have been analysed. The 1 H NMR line shape typical for anisotropic fluids with zero biaxiality (asymmetry) of magnetic shielding and the chemical shift anisotropy (CSA) of ca 0.33 ppm was observed and attributed to water molecules. CSA values for 13 C nuclei have been found in the range of 1.2-1.7 ppm. The difference between lyotropic liquid-crystalline (LC) ionogel phase and the solid one has been revealed, where the motions of RTIL and water molecules have been found to be dynamically segregated. The anisotropic 13 C NMR signal shape at 16.89 ppm shows the difference between LC ionogel and the lamellar phases, where usually the decreasing order parameter moving along hydrocarbon chain from the polar head is observed. It indicates, that the terminal −CH3 groups are more ordered and the supramolecular structures of [C10mim][Br], similar to some higher micellar RTIL aggregates are expected. In order to explain the experimental observations, the quantum chemistry DFT calculations of 1 H and 13 C magnetic shielding tensors of [C10mim] [Br] and various H-bond structures of H2O were performed.

The solid-state 1H, 31P NMR spectra and cross-polarization (CP MAS) kinetics in the series of samples containing amorphous phosphate phase (AMP), composite of AMP + nano-structured calcium hydroxyapatite (nano-CaHA) and...

O NMR spectra of pyridine N-oxide (PyO) complexes with the acids – acetic (AA), cyanoacetic (CyA), propiolic (PA), trichloroacetic (TCA), trifluoroacetic (TFA), hydrochloric (HCl) and methanesulfonic (MSA) – as well as some related molecules with intramolecular H-bonds (4-substituted picolinic acid N-oxides) were studied in an acetonitrile (ACN) solution. In order to evaluate the effect of proton positioning along the O–H…O bond on the measured chemical shifts the full geometry optimization was carried out, and 17O magnetic shielding tensors were calculated using density functional theory (DFT). The modified hybrid functional PBE1PBE with the 6-311++G** basis set and the gauge-including atomic orbital (GIAO) approach were applied. The solvent effect was taken into account by a polarized continuum model using the integral equation formalism (IEFPCM). Two stable structures were deduced for the PyO complexes with TCA and TFA that correspond to the H-bonds with and without proton transfer (PT). Two minima on the potential surface were separated by ca 0.2 Å. The experimental 17O NMR spectra have shown that the PyO-TCA complex in ACN can be considered as H-bonding with incipient PT, whereas it is known from neutron diffraction that in its crystalline state PT occurs. The proton location in PyO-TFA due to the thermally induced proton sharing was found at the middle point. The 17O NMR data for the acids with an intramolecular H-bond (nitroPANO, PANO and methoxyPANO) deviate from the general trend. The factors that can cause it, such as the substitution effect, persistence of nano-crystallites in a solution due to a low solubility, etc., have been discussed.

The cost of the rare‐earth metal cerium means that preparation of YAG : Ce is expensive. To overcome this, the garnet could partially be replaced by cheaper alternatives, while retaining the original properties of YAG : Ce. Composites with different polymers such as polyethylene glycol diacrylate (M280) and dipentaerythrityl hexaacrylate (M600) were therefore studied. YAG : Ce and boron nitride were added into the polymer matrix in order to obtain composites with enhanced thermal conductivity, necessary for high‐optical‐density applications. The physical properties of the composites were measured by using XRD, DSC, SEM, and NMR, and the most important characteristics for LED materials such as emission, excitation, decay time and quantum efficiency were analyzed. An LED prototype was developed to test and demonstrate the composites for practical applications. That developed device exhibited optical properties very close to those comprising a commercial garnet prototype, which was also developed for comparison. The main advantage of the proposed technology is that by using 2 time less the amount of YAG : Ce, almost the same light output was obtained compared to commercial phosphors.