New biotechnological approaches for a comprehensive characterization of AGL11 and its molecular mechanism underlying seedlessness trait in table grape

Wine research in the past years has mainly been focused on laboratory scale due to the possibility of controlling winemaking variables. Conversely, studies on wine quality in relation to the winemaking variables at the winery scale may be able to better account for the actual challenges encountered during wine production. Winemaking problems are recently arising from progressive changes in environmental conditions in relation to the terroir. It is important to realize that each wine region may have specific winemaking protocols and that winemakers often base their decisions on subjective, emotional, and empirical opinions. Due to all the above-mentioned issues, taking the correct decision in winemaking to achieve the desired goals may become even more challenging.

The own-rooted vineyard of Santorini is a unique case of vineyard worldwide that is been cultivated for thousands of years. On the island’s volcanic soil, the vines are still cultivated with traditional techniques, which are adapted to the specific and extreme weather conditions that prevail on it. While climate change is a reality in the Mediterranean region, will Santorini vineyard endure its impact? The study of the traditional training systems, techniques and vine density, as well as the application of sustainable solutions (cover crops and use of kaolin etc.) revealed sustainable methods for the adaptation of the local viticulture to new climatic phenomena that tend to be more and more frequent in the region due to climate change.

The main objective of this study was to establish if beet sugar produces a different concentration of “fruity” volatile aroma compounds (VOCs), compared to cane sugar when used for second alcoholic fermentation of Auxerrois sparkling wines. Auxerrois base wine from the 2020 vintage was separated into two lots; half was fermented with cane sugar and half with beet sugar (both sucrose products and tested for sugar purity). These sugars were used in yeast acclimation (IOC 2007), and base wines for the second fermentation (12 bottles each). Base wines were manually bottled at the Cool Climate Oenology and Viticulture Institute (CCOVI) research winery. The standard chemical analysis took place at intervals of 0, 4 weeks, and 8 weeks post-bottling. Acidity and pH measurements were carried out by an auto-titrator. Residual Sugar (g/L) (glucose (g/L), fructose (g/L)), YAN (mg N/L), malic acid, and acetic acid (g/L) were analyzed by Megazyme assay kits. parameters were analyzed by Megazyme assay kits. Alcohol (% v/v) was assessed by GC-FID. VOC analysis of base wines, finished sparkling wines, as well as the two sugars in model sparkling wine solutions, was carried out by GC-MS. VOCs included ethyl octanoate, ethyl hexanoate, ethyl butanoate, ethyl decanoate, ethyl-2-methylbutyrate, ethyl-3-methylbutyrate, ethyl 2-methyl propanoate, ethyl 2- hydroxy propanoate, 1-hexanol, 2-phenylethan-1-ol, ethyl acetate, hexyl acetate, isoamyl acetate and 2-phenylethyl acetate.

The poster presents the results of the 3rd year of activity of the project “Characterization of the wine productions of the italian regions. The DOC wine Colli Piacentini Gutturnio”.

Chitosan is a polysaccharide produced from the deacetylation of chitin extracted from crustaceous and fungi. In winemaking chitosan is mainly used in the clarification of grape juice and wine, stabilization of white wines, removal of metals and to prevent wine spoilage by undesired microorganisms. The addition of chitosan to model wine systems was able to retard browning, reduce levels of metallic ions (Fe and Cu) and to protect varietal thiols due to its antiradical activity1. The present experiment was planned in order to evaluate the use of chitosan as a secondary antioxidant at three different stages of Sauvignon blanc fermentation and winemaking. Sauvignon blanc juices from three different locations were obtained at a commercial winery in Marlborough, New Zealand. One lots of grapes was collected from a receival bin and pressed into juice with a water-bag press, and a further juice sample was collected from a commercial pressing operation. Chitosan (1 g/L, low molecular weight, 75 – 85% deacetylated) was added to the juice after pressing, after cold settling, after fermentation, or at all these stages. Controls without any chitosan additions were also prepared.