Potential deacidifying role of a commercial chitosan: impact on pH, titratable acidity, and organic acids in model solutions and white wine

Context and purpose of the study – This paper presents is the create, the study and amplographic description the new pink “Early Elgo Demetra” variety.

The rising trend of moderate wine consumption as a part of a healthy lifestyle promotes white wines with higher phenolic content because of their bioactive properties. Duration and temperature of the maceration process have a marked impact on the content and composition of wine phenolics. The aim of this study was to explore the effect of applying maceration processes of different durations and temperature on total phenolic content and flavan-3-ol compounds concentration of Malvazija istarska (Vitis vinifera L.) wines, an autochthonous Croatian white grape variety. Vinification took place at the Institute of Agriculture and Tourism (Poreč) where pre-fermentative two days cryomaceration treatment at 8 °C (CRYO), seven days maceration treatment at 16 °C (M7), and prolonged post-fermentative maceration treatments at 16 °C for 14 days (M14), 21 day (M21), and 42 days (M42) were studied and compared to non-maceration control treatment (C). Total phenolic content was determined by the Folin-Ciocalteu colorimetric method using a UV/VIS spectrophotometer and the results were expressed as gallic acid equivalents (mg/L GAE).

One of the major threats to viticulture is represented by fungal pathogens. Plasmopara viticola, an oomycete causing grapevine downy mildew, is one of the principal causes of grape production losses. The most efficient management strategies are represented by a combination of agronomical practices, fungicides’ applications, and use of resistant varieties. Plant resistance is conferred by the presence of resistance (R) genes. Opposed to them, susceptibility (S) genes are encoded by plants and exploited by pathogens to promote infection. Loss or mutation of S genes can limit the ability of pathogens to infect the host. By exploiting post-transcriptional gene silencing, known as RNA intereference (RNAi), it is possible to knock-down the expression of S genes, promoting plant resistance.

Grape stalks are a byproduct of the winemaking process and represent a valuable and inexpensive source of bioactive compounds. While their direct use in whole bunch fermentation is known, the majority of grape stalks are discarded, posing environmental and economic challenges.

Non-saccharomyces yeasts gained an increased interest in winemaking during the last decades, due to their ability to produce relevant amounts of polysaccharides. Moreover, a significant release of glutathione into the wine during fermentation was also observed with these strains, as well as an improvement of color stability and wine aroma profile. Valuable results have been obtained by hanseniaspora spp. concerning the release of polysaccharides and the production of acetic esters, mainly during fermentation.