Determination of zearalenone in malting barley

Tato bakalářská práce se zabývá sledováním obsahu zearalenonu ve sladovnickém ječmeni pomocí imunochemické metody ELISA a následně pomocí kapalinové chromatografie s hmotnostní detekcí (LC-MS/MS). V teoretické části byly charakterizovány základní pivovarské suroviny. Také byly popsány významné toxinogenní vláknité mikromycety. Pozornost byla věnována především vybraným fusariovým mykotoxinům (fumonisiny, trichotheceny, zearalenon). Dále byly popsány některé metody stanovení mykotoxinů. V experimentální části bylo metodou ELISA analyzováno 90 vzorků sladovnického ječmene různých odrůd. V 19 vzorcích byla stanovená koncentrace zearalenonu větší než limit kvantifikace. Nejvyšších hodnot koncentrace dosahoval vzorek ječmene odrůdy Wintmalt (39,2 g•kg-1), kde předplodinou byla kukuřice. Následně byly tyto vzorky podrobeny analýze pomocí LC-MS/MS. Pouze u čtyř vzorků byla koncentrace zearalenonu větší než limit kvantifikace, a to u vzorků ječmene odrůdy Blaník, Malz a Wintmalt. Dále byly analyzovány vzorky meziproduktů výroby sladu metodou LC-MS/MS. U žádného vzorku nebylo nalezeno množství zearalenonu větší než limit kvantifikace.This bachelor thesis deals with monitoring of zearalenone content in malting barley using immunochemical method ELISA and consequently method of liquid chromatography with mass spectrometry (LC-MS/MS). Theoretical part describes the brewing raw materials and important toxinogenic filamentous fungi. Special attention was drawn to selected fusarium mycotoxins (fumonisins, trichothecenes, zearalenone). It also describes some methods for determination of mycotoxins. Experimental section describes analyze 90 samples of malting barley of different varieties using method ELISA. In 19 samples zearalenone concentration was higher than limit of quantification. The highest level of zearalenone concentration (39,2 g•kg-1) contained barley, variety Wintmalt, where corn was used as a fore-crop. The samples were subsequently analyzed by LC-MS/MS. Zearalenone concentration was higher than limit of quantification only in four samples, namely in samples of Blaník, Malz and Wintmalt varieties of barley. Furthermore, the samples of intermediate products of malting process were analyzed by LC-MS/MS. No sample showed level of zearalenone higher than limit of quantification.

Monitoring of the occurrence of mycotoxins in beers from market retail

Tato diplomová práce se zabývá sledováním obsahu deoxynivalenolu, jeho metabolitu deoxynivalenol-3-b-D-glukopyranosidu a ochratoxinu A v pivech z maloobchodní sítě z České republiky, Polska a Slovenska. V teoretické části byla popsána obecná charakteristika mykotoxinů, jejich přenos ze sladovnického ječmene do piva a jejich výskyt v pivech. Dále byl zmíněn proces sladování a technologie výroby piva. Následně byly předloženy možnosti stanovení mykotoxinů chromatografickými a imunochemickými metodami. V experimentální části bylo analyzováno celkem 30 vzorků piv. Pro stanovení ochratoxinu A byla použita ultra vysokoúčinná kapalinová chromatografie s fluorescenční detekcí (UPLC/FLR) a pro stanovení deoxynivalenolu a jeho metabolitu vysokoúčinná kapalinová chromatografie ve spojení s hmotnostní detekcí (HPLC/MS). Ochratoxin A byl nalezen ve 25 vzorcích s rozmezí kontaminace 0,6 - 82,5 ng·l-1. Deoxynivalenol byl detekován ve 24 vzorcích s koncentračním rozmezím 2,29 - 12,57 ug·l-1 a deoxynivalenol-3-b-D- glukopyranosid se vyskytoval v 19 vzorcích v rozmezí kontaminace 2,45 - 12,47 ug·l-1. Dále byl posuzován vzájemný vztah mezi vznikem gushingu a přítomnosti mykotoxinů v pivu. Mezi těmito dvěma parametry nebyla žádná závislost nalezena. Bylo tedy prokázáno, že přítomnost mykotoxinů v pivu nemůže být pokládán za přímý faktor vzniku gushingu.This master thesis deals with monitoring of a content of deoxynivalenol, its metabolite deoxynivalenol-3-b-D-glucopyranoside and ochratoxin A in beer samples collected from retail market in the Czech Republic, Poland and Slovakia. The theoretical part describes general characteristics of mycotoxins, its transfer from field barely through malt to beer and its occurrence in beers. Malting process and brewing technology were also mentioned. Subsequently possibilities for a determination of the mycotoxins by the chromatografic and immunochemical method were presented. The experimental section describes analysis of 30 samples of beer. The analyses were conducted using ultra high-performance liquid chromatography with fluorimetric detection (UPLC/FLR) for ochratoxin A and high-performance liquid chromatography coupled with mass spectrometer (HPLC/MS) for deoxynivalenol and its metabolite. Ochratoxin A was detected in 25 of the 30 samples in concentration range of 0,6 - 82,5 ng·l-1. Deoxynivalenol was found in 24 of the 30 samples with concentration range of 2,29 - 12,57 ug·l-1 and deoxynivalenol-3-b-D-glucopyranoside was occure in 19 of the 30 samples in concentration range of 2,45 - 12,47 ug·l-1. It was also assessed the relationship between beer gushing and presence of mycotoxins in beer. No connection between the parameters has been found. Consequently it is not possible to predict beer gushing from the presence of mycotoxins.

The Occurrence of Mycotoxins in Beers from Retail Shops

In 2016, contents of mycotoxin deoxynivalenol, its metabolite deoxynivalenol-3-β-D-glucopyranoside and ochratoxin A, in beers from Czech, Polish and Slovak retail shops were studied. Totally, 30 beer samples were analyzed. Deoxynivalenol and its metabolite were determined using high performance liquid chromatography with mass detection (HPLC/MS) HPLC, and ultra-high performance liquid chromatography with fl uorescence detection (UPLC/FLR) was employed for the determination of ochratoxin A. Deoxynivalenol was detected in 25 samples in the concentration range of 1.54 - 12.57 μg·l-1 and deoxynivalenol-3-β-D-glucopyranoside was present in 27 samples in the contamination range of 1.18 - 12.47 μg·l-1. Ochratoxin A was detected in the contamination range of 1.2 – 82.5 ng·l-1

Characterization of the fusarium sambucinum species complex and detection of multiple mycotoxins in brazilian barley samples

This study investigated the fungal diversity in Brazilian barley samples, focusing on the Fusarium sambucinum species complex and the presence of multiple mycotoxins: aflatoxins B1, B2, G1, G2 beauvericin (BEA), enniatins (ENNs) A, A1, B, and B1, deoxynivalenol (DON), fumonisins (FB) B1 and B2, HT-2 and T-2 toxins, nivalenol (NIV) and ochratoxin A (OTA) from two different regions, São Paulo (SP) and Rio Grande do Sul (RS). The majority of the isolates belonged to the Fusarium sambucinum species complex (FSAMSC), with F. graminearum s.s. characterized as the major contaminant. F. meridionale and F. poae were the second most frequent fungi isolated from SP and RS, respectively. All of the F. graminearum s.s. isolates demonstrated 15-ADON genotype, whereas F. poae and F. meridionale were all NIV. The majority of the F. cortaderiae isolates were NIV, with only one 3-ADON genotype. Mycotoxin analysis revealed that none of the samples were contaminated by aflatoxins, OTA, FB2 and type A trichothecenes, however, all of the samples were contaminated with at least one Fusarium toxin. Contamination by DON, ZEA, ENNB and ENNB1 levels were significantly higher in RS. Co-contamination of BEA, DON, ENNs, NIV and ZEA in 18.5% and 24.2% of the analyzed samples was observed, from SP and RS respectively. More than 20% of the samples from RS presented DON and ZEA levels above the regulations established by Europe and Brazil. The results provide further information on the FSAMSC from South America and detected multiple Fusarium toxins in barley samples. This highlights the importance for further studies on the possible interactions of these mycotoxins in order to determine potential risks to animal health136CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP167039/2017-2Sem informação2017/04811-