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In this work the long-term antibacterial activity of silver doped titania coatings is studied systematically as a function of the titania layer structure (with and without molecular template) and the amount and physical properties of the silver dopant. Silver was incorporated in two different ways into the titania sol-gel films, either by co-deposition, i.e., adding the silver ions directly to the precursor sol of the layer or by postsynthetic impregnation of the mesoporous titania coating. The structure and morphology of the layers were investigated using transmission and scanning electron microscopy, whereas the silver content was determined by Rutherford backscattering spectrometry. Antibacterial properties against Escherichia coli bacteria were studied by colony forming unit assay and agar diffusion method. It was found that directly after preparation, all composite coatings show antibacterial activity both in the dark and under visible light illumination. The antibacterial activity of the co-deposited samples vanished after the first use despite their high and constant remaining silver content (2.597 at%). This type of coating was not effective in agar diffusion tests at all. The antibacterial activity of the impregnated coatings with lower silver contents (0.596 at% and 1.961 at%), however, showed long-lasting antibacterial effect both in the colony forming unit assay and in agar diffusion tests as well. This can be attributed to the fact that the silver content is distributed over the mesoporous network of the titania coating and is effective during the long-term tests. Fig. 2 Toluene adsorption-desorption isotherms at 294 K and normalized pore radius distribution of (a and b) TiO 2 , (c and d) pTiO 2 , and (e and f) TiO 2 -AgNO 3 type titania coatings determined by ellipsometric porosimetry.This journal is

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Radványi D., Juhász R., Németh Cs., Suhajda A., Balla Cs., Barta J. (2012): Evaluation of the stability of whipped egg white. Czech J. Food Sci., 30: 412-420.An investigation was made into the effects of various egg white products and sweeteners on the stability and organoleptic properties of egg white foams. 12 foam products were prepared from egg white and sweeteners. The egg white was produced in the following forms: raw liquid egg white, pasteurised liquid egg white, liquid egg white treated at 55°C for 24 h, and spray-dried egg white powder. Three different sweeteners were used: sucrose, fructose-glucose syrup, and fructo-oligosaccharide syrup. The storage stability, firmness, adhesiveness based on the texture profile analysis, and organoleptic properties of the foams were evaluated. The flow curves of raw materials were also determined by means of a rotational viscometer. The results indicated that sucrose among the sweeteners and egg white powder among the egg white products are the most suitable for producing egg white foam and enhancing its stability. However, liquid egg white heat treated at low temperature also proved to be an appropriate choice for making stable egg white foams for the confectionery industry.

In our tests, we artificially infected liquid whole egg samples with Salmonella enteritidis, Listeria monocytogenes, and Staphylococcus aureus bacteria, and then treated the samples in "Food Lab900" high hydrostatic pressure (HHP) instrument for 3-17 min at 200-400 MPa. Subsequently, the change of the viable cell count of the specific bacteria has been tested. In addition to the samples infected with various bacteria, non-infected samples were also treated in each test and the change in viable cell count, colour and viscosity of the samples upon the effect of the treatment. In summary, it can be concluded that in each test of our investigations, the viable cell count of S. enteritidis critical for egg products is reduced significantly, while the reduction of the total viable cell count was around two magnitudes. Additionally, based on our results, microbial destruction, reduction of enthalpy (denaturation of egg white) caused by the treatment at HPP, and colour change are primarily affected by the pressure level, while the changes in rheological properties are also significantly affected by the duration of high pressure treatment (p < 0.05).