Search

In this paper we focus on possibilities of using natural microflora from vineyards to enhance spontaneous fermentation. Obtained yeast isolates, naturally occurring in vineyards, which were previously isolated in 2017 and 2018, were used for inoculation of Hibernal grape must. Spontaneously fermented musts and musts with the yeast isolates from 2017 and 2018 were compared. Basic parameters of the musts (sugar concentration, pH, concentration of titratable acids, concentration of assimilated nitrogen) were analysed studied, and a sensory analysis of the resultant wines was performed. The fermentation with the yeast isolates was quick and smooth. In the spontaneous fermentation lower ethanol production rate was observed at the end of the fermentation process. During the sensory evaluation, fruitiness of the spontaneously fermented batch was lower, but its vegetal characteristic was pronounced. The variant with the yeast isolates from 2017 was described as smooth, and the variant with yeast isolates from 2018 was evaluated as slightly vegetal.

The green biosynthesis of nanoparticles is one of the most discussed topic of current nanotechnology. It has been estimated the plants, bacteria, yeasts or some lower organism could synthesize nanoparticles such as quantum dots, organic and inorganic based nanoparticles. Yeasts are eukaryotic microorganisms and generally, several strains play an important role in food industry due their ability to sugar fermentation. A novel approach of their use could be a production of metal nanoparticles and nanostructures via their reducing enzymes intracellularly or extracellularly. The focus of this review is the application of yeast in the green synthesis of inorganic nanoparticles and the innovation use in the fermentation industry.

Rosé wines has gained a great popularity not only in Czech Republic but also elsewhere in the world. Rosé are produced mostly from traditional varieties such as 'Pinot Noir', 'Blaufrankisch' (Lemberger), 'Zweigeltrebe', 'Merlot' and 'Cabernet Sauvignon'. Entirely new act play rosé wines made from blue Czech interspecific grape varieties, such as 'Cerason' or 'Laurot'. For samples of wines (concrete 'Laurot', 'Cerason', 'Kofranka', 'Pinot noir', 'Merlot' and 'Blaufrankisch') are normally carried out measurements of fundamental analytical values. Furthermore, spectrophotometric measurements were carried out - determination of total phenols, total anthocyanins and the optical density at 280 nm (OD280), total flavanols, reducing power and antiradical activity. The results show that most phenolic compounds and highest antiradical activity has the variety 'Laurot'. This variety has besides ideal pink color for rosé wine similarly as 'Blaufränkisch' variety. The new interspecific varieties were higher antiradical activity and therefore health benefits. When choosing a suitable technology for its fruitiness, higher acidity and higher resistance to fungal diseases appear to be interesting for the production of rosé wines, not only from organic production.Rosé wines has gained a great popularity not only in Czech Republic but also elsewhere in the world. Rosé are produced mostly from traditional varieties such as 'Pinot Noir', 'Blaufrankisch' (Lemberger), 'Zweigeltrebe', 'Merlot' and 'Cabernet Sauvignon'. Entirely new act play rosé wines made from blue Czech interspecific grape varieties, such as 'Cerason' or 'Laurot'. For samples of wines (concrete 'Laurot', 'Cerason', 'Kofranka', 'Pinot noir', 'Merlot' and 'Blaufrankisch') are normally carried out measurements of fundamental analytical values. Furthermore, spectrophotometric measurements were carried out - determination of total phenols, total anthocyanins and the optical density at 280 nm (OD280), total flavanols, reducing power and antiradical activity. The results show that most phenolic compounds and highest antiradical activity has the variety 'Laurot'. This variety has besides ideal pink color for rosé wine similarly as 'Blaufränkisch' variety. The new interspecific varieties were higher antiradical activity and therefore health benefits. When choosing a suitable technology for its fruitiness, higher acidity and higher resistance to fungal diseases appear to be interesting for the production of rosé wines, not only from organic production.