National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Estery karotenoidů v potravinách a potravinových doplňcích
MICHALČÍKOVÁ, Anna
Carotenoids are lipophilic dyes; their production is very important for photosynthetic processes as well as for tissue protection in leaves and as attractants in fruits. They are also crucial in human/animal nutrition for their antioxidant effects. Carotenoids can be found in plant and animal tissues both in free and esterified forms. The main goal of this bachelor thesis was to establish the method of saponification of carotenoid extracts from fruits, food supplements and subsequent analysis of the presence of carotenoid esters by HPLC. Saponification was tested with sodium and potassium hydroxides. Content of carotenoid esters was detected in food samples and in selected food supplements with presumed high carotenoid content. Findings are discussed in terms of carotenoid uptake in human digestive tract.
Rebecca and Eliezer at the well a mysterious oil painting from the Historical Museum of the Slovak National Museum at the Bratislava Castle
Hradilová, J. ; Kližanová, H. ; Bezák, M. ; Holcová, K. ; Bezdička, Petr
Light microscopy, scanning electron microscopy and microanalysis, X-ray powder micro-diffraction, infrared micro-spectrometry as well as palaeontological analysis have been applied in order to solve the question of provenance of the oil-on-canvas painting Rebecca and Eliezer at the well. In addition to the finding of pigments important for the dating of the painting, as, e.g. Naples yellow (Pb2Sb2O7), or smalt, fossil nannoplankton was described in the carbonate-rich clay ground. It indicates the use of marine sediments of Eocene to Oligocene age. According to mineralogical and paleontological data this ground may be included among grounds used in Italy, particularly in the 17th century. The studied painting is today greatly altered due to extensive reworkings. Prussian blue was used to overpaint faded ultramarine and degraded smalt, which is visibly affected by saponification processes.

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