Since deoxynivalenol (DON), the main representative of Fusarium toxic secondary metabolites, is a relatively common natural contaminant in barley, its traces can be detected in many commercial beers. Our previous study reporting for the first time the occurrence of relatively high levels of DON-3-glucoside (DON-3-Glc) in malt and beer prepared from relatively "clean" barley (semiscale experimental conditions) induced a follow-up investigation focused on this DON conjugate in commercial beers. The current survey involving in total 176 beers, representing different brands, and collected at various markets, has documented a ubiquitous occurrence of DON-3-Glc in this product. Its levels even exceeded that of free DON in some samples; the highest level found was 37 microg/L. In addition to glucosylated DON, its acetylated forms (ADONs) were also common contaminants in most of the beers. Generally, stronger beers (higher alcohol content) tended to contain higher levels of DON and its conjugates. No distinct relationship between the contamination of malt and beer was observed in samples collected from several breweries. Attention was also paid to comparison of data on malts obtained by LC-MS/MS and ELISA DON-dedicated kits. The latter provided apparently higher levels of DON, the most distinct difference being observed for malts processed at higher temperatures (caramel and roasted malts). The nature of this phenomenon has not yet been explained; in addition to cross-reacting species, other factors, such as the higher content of dark pigment, can also be the cause.

Baroň M., Fiala J. (2012): Chasing after minerality, relationship to yeast nutritional stress and succinic acid production. Czech J. Food Sci., 30: 188-193. Minerality is certainly one of the most mysterious and most valuable tones of wine taste and it is very often associated with the concept of terroir. The isotachophoresis was used for determination of cations -minerals in two wines from vineyards with different soil conditions, with and without exceptional "minerality". However, it was found that it has nothing to do with minerals. More attention was paid to the relationship between the nutritional stress of yeasts and succinic acid production, which can result in a final difference in the taste of wine. In addition, sensory evaluation was used to reveal differences between wines with increasing levels of succinic acid.

In recent years, interest in hop-derived constituents, especially for prenylflavonoids has grown, as they have a wide range of biological properties including antioxidant, anticarcinogenic and antimicrobial activities. Two main hop prenylflavonoids, xanthohumol and isoxanthohumol, and hop extract enriched in prenylflavonoids, were tested for their antiproliferative activities on colon cancer cell lines, HT-29 and SW620, and a noncancerous cell line, IEC-6. It was confirmed that both xanthohumol and isoxanthohumol inhibited cell proliferation, even at micromolar concentrations. For cell line HT-29, the IC 50 was 1.2 ± 0.9 and 16.9 ± 0.9 μmol dm À3 for xanthohumol and isoxanthohumol, respectively. Similar values were obtained for SW620 cells (2.5 ± 0.2 and 37.3 ± 3.2 μmol dm -3 ). None of the pure prenylflavonoids that were tested affected the proliferation of the noncancerous cell line, IEC-6. The effect of the hop extract containing xanthohumol was also tested for antiproliferative activities on the cancer cell lines, HT-29 (IC 50 = 3.1 ± 0.2 μmol dm -3 ) and SW620 (IC 50 = 1 ± 0.2 μmol dm À3 ), and on the cell line, IEC-6 (IC 50 = 65.5 ± 11.3 μmol dm À3 ). The results showed a similar trend to that for pure compounds, suggesting a possible future application of hop extracts in the pharmaceutical industry.