The use of contaminated raw materials can lead to the transfer of mycotoxins into the final product, including beer. This study describes the use of the commercially available immunoaffinity column 11+Myco MS-PREP® and UPLC-MS/MS for the determination of mycotoxins in pale lager-type beers brewed in Czech Republic and other European countries. The additional aim of the work was to develop, optimize and validate this analytical method. Validation parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), precision and accuracy were tested. The calibration curves were linear with correlation coefficients (R2 > 0.99) for all mycotoxins under investigation. The LOD ranged from 0.1 to 50 ng/L and LOQ from 0.4 to 167 ng/L. Recoveries of the selected analytes ranged from 72.2 to 101.1%, and the relative standard deviation under conditions repeatability (RSDr) did not exceed 16.3% for any mycotoxin. The validated procedure was successfully applied for the analysis of mycotoxins in a total of 89 beers from the retail network. The results were also processed using advanced chemometric techniques and compared with similar published studies. The toxicological impact was taken into account.
Mycotoxins are widely studied by many research groups in all aspects, but the stability of these compounds needs further research for clarification. The objective of this study is to evaluate deoxynivalenol and zearalenone stability during all steps of the malting and brewing processes. The levels of these compounds decreased significantly during the production process (barley to beer). During the malting process, the DON levels decreased significantly in the steeping, germination, and malting steps (62%, 51.5%, and 68%, respectively). Considering ZEN, when the levels were compared between barley and the last step of the process, a significant decrease was observed. Most of the mycotoxins produced were transferred to the rootlets and spent grains, which is advantageous considering the final product. Furthermore, the mycotoxin dietary intake estimation was included in this study. The results proved that if the concentrations of target mycotoxins in raw material are under the limits established by the regulations, the levels decrease during the malting and brewing processes and make the beer secure for consumers. The quality of the five commodities involved in the beer process plays a decisive role in the creation of a safe final product.
- MeSH
- dietární expozice analýza MeSH
- dospělí MeSH
- Fusarium MeSH
- ječmen (rod) mikrobiologie MeSH
- kontaminace potravin analýza MeSH
- lidé MeSH
- pivo analýza MeSH
- potravinářský průmysl MeSH
- trichotheceny analýza MeSH
- zearalenon analýza MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
α-Galactosidases are assigned to the class of hydrolases and the subclass of glycoside hydrolases (GHs). They belong to six GH families and include the only characterized α-galactosidases from yeasts (GH 27, Saccharomyces cerevisiae). The present study focuses on an investigation of the lactose-inducible α-galactosidase produced by Papiliotrema flavescens. The enzyme was present on the surface of cells and in the cytosol. Its temperature optimum was about 60 °C and the pH optimum was 4.8; the pH stability ranged from 3.2 to 6.6. This α-galactosidase also exhibited transglycosylation activity. The cytosol α-galactosidase with a molecular weight about 110 kDa, was purified using a combination of liquid chromatography techniques. Three intramolecular peptides were determined by the partial structural analysis of the sequences of the protein isolated, using MALDI-TOF/TOF mass spectrometry. The data obtained recognized the first yeast α-galactosidase, which belongs to the GH 36 family. The bioinformatics analysis and homology modeling of a 210 amino acids long C-terminal sequence (derived from cDNA) confirmed the correctness of these findings. The study was also supplemented by the screening of capsular cryptococcal yeasts, which produce the surface lactose-inducible α- and β-galactosidases. The production of the lactose-inducible α-galactosidases was not found to be a general feature within the yeast strains examined and, therefore, the existing hypothesis on the general function of this enzyme in cryptococcal capsule rearrangement cannot be confirmed.
- MeSH
- alfa-galaktosidasa chemie genetika izolace a purifikace metabolismus MeSH
- Basidiomycota klasifikace enzymologie genetika růst a vývoj MeSH
- Cryptococcus MeSH
- cytosol enzymologie MeSH
- DNA fungální genetika MeSH
- fungální proteiny chemie genetika izolace a purifikace metabolismus MeSH
- geny hub genetika MeSH
- glykosidhydrolasy metabolismus MeSH
- komplementární DNA MeSH
- koncentrace vodíkových iontů MeSH
- konformace proteinů MeSH
- laktosa metabolismus MeSH
- molekulární modely MeSH
- molekulová hmotnost MeSH
- sekvence aminokyselin MeSH
- sekvenční analýza proteinů MeSH
- sekvenční seřazení MeSH
- stabilita enzymů MeSH
- substrátová specifita MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
