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Wine adulteration and its detection based on the rate and the concentration of free amino acids
139-151Views:364Following the definition of wine adulteration, the authors briefly review its history from ancient times to present day and describe the methods that are applied for adulteration of wine from the historical point of view. More space is devoted to the Hungarian wine adulteration and to the detailed reports of the early methods, which attempted to discover fake wine. It describes in detail the current situation of wine adulteration and the fight against counterfeiting. The second half of the review article presents some examples of the analytical chemistry techniques with which fake wines can be detected. In doing so, priority is given to the discussion of high performance liquid chromatography and gas chromatography applications. The end of this paper describes the free amino acid content of wines, and the possibilities of using the results for detection of wine adulteration.
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Selenium speciation analysis of selenium-enriched food sprouts
23-28Views:218In this present study, we prepared selenium-enriched pea and wheat sprouts. During our research we aimed not only to measure the total selenium content of the sprouts but to identify different selenium species.
Scientifical researches show why the analytical examination of different selenium (Se) species is necessary: consumption of all kind of Se-species is useful for a person who suffers in selenium deficit, while there is significant difference between effects of different Se-species on person, in whose body the Se-level is just satisfactory. Biological availability, capitalization, accumulation, toxicity of Se-species are different, but the main difference was manifested in the anti-cancer effect of selenium.
During our research selenium was used in form of sodium selenite and sodium selenate, the concentration of the solutions used for germination was 10 mg dm-3. Control treatment meant germination in distilled water. Total selenium content of sprout samples was measured after microwave digestion by inductively coupled plasma mass spectrometry (ICP-MS). Different extraction solvents were applied during sample preparation in order to separate different Se-species (0.1 M and 0.2 M HCl or 10 mM citric acid buffer). We wanted the following question to be answered: Which extraction solvent resulted the best extraction efficiency? Selenium speciation analysis of sprout sample extracts was performed by high performance liquid chromatography with anion exchange column, detection of selenium species was performed by ICP-MS.
Evaluating our experimental results we have been found that significant amount of selenium of inorganic forms used during germination transformed into organic selenium compounds. There was difference between the amount of Se-species in pea and wheat sprouts and selenium uptake and repartition of selenium species were depended on Se-form used during germination. In addition the chromatogram analysis made us clear as well, that the citric acid solvent proved to be the most effective extraction solvent during sample preparation int he view of organic Se species.