Luděk Hřivna

Intersection of mycotoxins from grains to finished baking

This work is focused on the evaluation of the content of deoxynivalenol and zearalenone in samples of winter wheat of the following varieties: Sultan, Cubus, Akteur, Seladon, Mulan, Chevalier, Evina, Hewitt, Bohemia, Baletka. The total amount of 10 samples harvested in 2011 and 2012 was evaluated and included variants both treated and untreated against fungal diseases. The samples were adjusted for mycotoxicological determination and subsequently measured by the ELISA method. The content of deoxynivalenol (DON) and zearalenone (ZEA) was measured in grain, flour and breadrolls in all samples. Out of all samples 43% were found to have positive content of DON and 75% of ZEA. In the treated variants, the average DON content was found to be 115 µg.kg -1 in grain, 77 µg.kg -1 in flour and 97 µg.kg -1 in pastries. In the untreated variants, the average DON content was found to be 208 µg.kg -1 in grain, 103 µg.kg -1 in flour and 128 µg.kg -1 in pastries. Moreover, the average ZEA content in the treated variant was 4.95 µg.kg -1 in grain, 3.38 µg.kg -1 in flour and 4.51 µg.kg -1 in pastries, in the non-treated variant average ZEA content in grain was 3.07 µg.kg -1 , 4.97 µg.kg -1 in flour and 2.81 µg.kg -1 in pastries. The maximal acceptable limits given by the valid legislation were not exceeded in any analysed sample. It can be concluded wheat grain grown in the Czech Republic, whether it is treated or untreated by fungicides, is not dangerous for consumers. The content of both mycotoxins is not dependent on each other, and the untreated variant has a slightly higher dependency between DON and ZEA.

THE EFFECT OF STORAGE TEMPERATURE ON THE QUALITY AND FORMATION OF BLOOMING DEFECTS IN CHOCOLATE CONFECTIONERY

The study aimed at assessing changes in the quality of certain types of chocolate products over the storage period with particular focus on the formation and development of fat and sugar bloom in chocolate products. Seven products were selected in collaboration with a chocolate factory to undergo monitoring and analysis and stored at four temperature regimens (6 °C, 12 °C, 20 °C and 30 °C). Five samplings were carried out over the storing period (18 weeks) for evaluation of the dynamics of changes in their quality. Each sampling was accompanied by sensory evaluation; selected physical attributes were also analysed: changes in colour (∆E*ab) within the CIE (L*a*b) system and changes in hardness using the TIRAtest 27025. The results showed a significant effect of storing temperature on the intensity of changes in the quality of products. The results of sensory evaluation of selected products showed that the highest quality for the majority of descriptors was achieved by products stored at temperatures of 6 °C and 12 °C. As regards samples stored under the temperature regimen of 20 °C, the products started to show visible differences, caused primarily by the formation of fat bloom while storing at 30 °C proved to be extremely unsuitable for all the tested products. Since storing temperatures of 6, 12 and 20 °C did not considerably affect hardness and colour of each product, no distinct changes occurred under such temperature regimens. From the aspect of analytical measurements of colour and hardness of each product, storing at temperatures of 20 °C can be termed appropriate. In all the analyses, the effect of the temperature regimen of 30 °C was significantly negative due to defects caused by blooms on the chocolate, meaning that such temperatures are not advisable for storing chocolate products, even over a short term.

Dynamika klíčení během posklizňového dozrávání sladovnického ječmene.

VIERA ŠOTTNÍKOVÁ, VRATISLAV PSOTA, LUDĚK HŘIVNA, TOMÁŠ GREGOR, LENKA SACHAMBULA 1 Ústav pěstování, šlechtění rostlin a rostlinolékařství, Mendelova univerzita v Brně, Zemědělská 1, 613 00 Brno / Department of Crop Science, Breeding and Plant Medicine, Mendel University in Brno, Zemědělská 1, CZ-613 00 Brno 2 Výzkumný ústav pivovarský a sladařský, a. s., Sladařský ústav Brno, Mostecká 7, 614 00 Brno / Research Institute of Brewing and Malting, Malting Institute, Mostecká 7, 614 00 Brno, Czech Republic e-mail: sotnik@mendelu.cz

Stanovení extraktu v zrnu ječmene enzymatickou cestou.

TOMAS GREGOR, RADIM CERKAL, LUDĚK HŘIVNA, VIERA SOTTNIKOVA Ustav technologie potravin, Agronomicka fakulta, Mendelova univerzita v Brně / Dpt. of Food Technology, Faculty of Agronomy, Mendel University in Brno, Zemědělska 1, 613 00 Brno, Czech Republic Ustav pěstovani, slechtěni rostlin a rostlinolekařstvi, Agronomicka fakulta, Mendelova univerzita v Brně / Dpt. of Crop Science, Breeding and Plant Medicine, Faculty of Agronomy, Mendel University in Brno, Zemědělska 1, 613 00 Brno, Czech Republic e-mail: tomas.gregor@mendelu.cz.