Vesna Zechner-Krpan

Significant advances in winemaking equipment and processes, as well as a deeper understanding of the role of yeast, have significantly improved wine quality throughout history. This paper examines critical aspects related to the use of commercial wine yeast starter cultures in the fermentation of grape and fruit wines, with a focus on berry wines and blackberry wine, which is the most predominant berry wine in Croatia. While the production of grape wines remains the most significant, fruit wines are gaining importance due to their composition, which contains a variety of bioactive compounds. Although spontaneous fermentation is still preferred by some winemakers, controlled or inoculated fermentation, based on the use of wine yeast starter cultures, is predominantly employed in modern winemaking. The selection of suitable yeast strains for grape wines is easier than for fruit wines, as the broader availability of commercial yeasts for grape wines contrasts with the limited selection offered for fruit wine production due to the smaller fruit wine market. The selection of Saccharomyces and, more recently, non-Saccharomyces yeast strains with desirable characteristics are crucial for the production of high-quality wines. Selection criteria for wine yeasts have evolved to meet modern consumer preferences and focus on technological properties, secondary flavor development and health effects.

Analizirani uzorci vina sorte Rajnski rizling iz vinogorja Plešivica-Okić proizvedeni su tijekom tri uzastopne godine (2009., 2010. i 2011.) na jednom obiteljskom gospodarstvu. Koncentracije alkohola, ukupnih i hlapljivih kiselina, ukupnog SO2 , glic...

Morphogenesis, volume and number of hop (Humulus lupulus L.) glandular trichomes, and their influence on alpha-acid accumulation in fresh bracts of hop cones: The ESEM investigations revealed the morphogenesis of peltate glandular trichomes, which was divided into five phases. In phase one, new peltate glandular trichomes were initiated; in phase two, they were differentiated; in phase three trichomes grew vigorously; in phase four they were determined; in the fifth and final phase they came to maturity. Volume of glandular trichome during the different phases of morphogenesis varied from 0.25 × 10^-2 mm³ in phase 1, to 1.95 × 10^-2 mm³ in phase 5. More glandular trichomes are placed on the base of the adaxial side of bracts (average 7 mm^-2) than on the base of abaxial side (average 5.8 mm^-2). In this research, positive Spearman's rank order correlations were found between the average number of glandular trichomes and content of α-acids as well as between the average volume of glandular trichomes and content of α-acids.