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Smart edible films sensitive to pH
Jarošová, Gabriela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
This bachelor thesis is focused on smart edible films sensitive to pH. The theoretical part deals with smart packaging including legislation. The main compound for the film preparation is chitosan, which is described and anthocyanins serving as the color indicator. At first, the anthocyanins were isolated from red cabbage using extraction. The edible films were prepared from chitosan, corn starch and anthocyanins. Pentasodium triphosphate was used as a crosslinking agent. The layers were subjected to the solubility test, which showed smallest decrease in case of fast drying in the dryer, namely 14,5 %. The color reaction on the pH change was studied. It was found that the prepared layers reacted to every pH change, the most significant reaction was to pH 1 and 3.
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Smart edible films sensitive to pH
Jarošová, Gabriela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
This bachelor thesis is focused on smart edible films sensitive to pH. The theoretical part deals with smart packaging including legislation. The main compound for the film preparation is chitosan, which is described and anthocyanins serving as the color indicator. At first, the anthocyanins were isolated from red cabbage using extraction. The edible films were prepared from chitosan, corn starch and anthocyanins. Pentasodium triphosphate was used as a crosslinking agent. The layers were subjected to the solubility test, which showed smallest decrease in case of fast drying in the dryer, namely 14,5 %. The color reaction on the pH change was studied. It was found that the prepared layers reacted to every pH change, the most significant reaction was to pH 1 and 3.
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Vliv macerace rmutu pří výrobě rosé vín
Vrbová, Libuše
This thesis deals with the influence of maceration of the mash in rosé winemaking. The literary section describe the phenolic compounds contained in grapes, the possibility of producing rosé wines and factors affecting the course of maceration. The aim of the work was to determine what type of maceration is the most suitable for the production of rosé wines. For the observed samples were examined maceration time and the influence of sulfur dioxide. He evaluated the sensory profile of wines colourists range using the CIE L * a * b * and the content of phenolic compounds. The experiment was conducted at the blue grape variety 'Pinot Noir'. Of ground grapes were created two variants. Mash without addition of SO2 and mash with the addition of sulfur dioxide. For each variant was produced six rosé wines with different length of maceration of the mash. Desired time maceration were 0, 5, 10, 15, 20 and 25 hours. Found mash conducted in non-inert conditions at 13 ° C. The results implies that the best time maceration for the production of rosé wines from varieties 'Pinot Noir' is 15 hours with the use of sulfur dioxide.
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Vliv různých podmínek zrání na změny ve složení fenolických látek ve víně
Beran, Václav
In the experiment the influence of different storage conditions of annual bottle aging on changes in the composition of phenolic compounds in white and red wines was observed. Total phenolics, flavanols, anthocyanins and antiradical activity were observed. A higher content of phenolics and a higher antiradical activity were detected in red wines. Higher temperature induces a higher content of phenolics in white wines. In red wines, higher temperature induces a lower content of total phenols. The content of flavanols in white and red wines decreases more at a higher temperature. The decrease of anthocyanins was observed in all red wines. Antiradical activity has increased in white wines with a cork stopper. In red wines, antiradical activity has decreased. The best storage conditions are low temperature and darkness. Classic cork stopper is the best closure for red wines. White wines closed by a screw cap were sensory evaluated more positively, cork stopper induces a higher antiradical activity.
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Technologické možnosti pří výrobě rosé vín
Vrbová, Libuše
The thesis deals with the technological possibilities in the production of rosé wines. In the first two chapters, discusses the history and current production of rose wines in the Czech Republic and abroad. The third chapter deals with the appropriate varieties of grapes. Further work is focused on the production itself rosé wines. The technology is described from the harvest of grapes in the vineyard to the subsequent storage of the product. The last chapters are devoted to the phenolic substances contained in the production of rosé wines and claret. Today, rosé wines have an important position on the Czech market. Absolute majority of winemakers produce rose wines in the way of short maceration of blue grapes, eventually without maceration.
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