Within-vineyard spatial variation impacts methoxypyrazine accumulation in the rachis of Cabernet-Sauvignon

Pre-fermentative skin maceration is a technique used in white wine production to enhance varietal aroma, but it can increase protein concentration, leading to protein instability and haze formation [1]. To prevent protein instability, wine producers typically use fining agents such as bentonite, before wine bottling, which can negatively impact sensory characteristics and produce waste [2,3]. The aim of this study was to understand the impact of alternative techniques such as the application of polysaccharides (k-carrageenan and chitosan) on protein stability and on the wine macromolecular composition.

During the tasting of a fine, old wine, the aromas generated in the glass are intertwined in an intimate, complex manner, expressing the fragrance of the aging bouquet. This aging bouquet, which develops during bottle storage through a complex transformation process, may result in a broad palette of nuances. Among these, undergrowth, truffle, toasted, spicy, licorice, fresh red- and black-berry fruit and mint descriptors were recently identified as features of its olfactory representation for red Bordeaux wines. Although a targeted chemical approach focusing on volatile sulfur compounds revealed the role played by dimethyl sulfide, 2-furanmethanethiol, and 3-sulfanylhexanol as molecular markers of the typicality of the wine aging bouquet of red Bordeaux wines, its chemical transcription has only partially been elucidated.

During cold storage, grapes undergo changes that affect their visual, mechanical, and organoleptic properties, potentially impacting quality and negatively influencing consumer acceptance. Key parameters include uniform color, crunchiness, and flesh consistency. We evaluated the influence of two distinct packaging methods on the chromatic characteristics, hardness, and pedicel detachment resistance of fourteen new seedless white and red grape varieties during cold storage. These factors are crucial for maintaining the quality of the product and extending its shelf-life. The novel grape varieties were obtained through a breeding program at CREA-VE of Turi, Southern Italy.

Temperature extremes affect grapevine physiology, as well as grape quality and production. In most grape growing regions, frost or heat wave events are rare and as such conducting a risk analysis using robust statistics makes the use of long term daily data necessary.

Many volatile compounds of different chemical/biochemical origin contribute to wine aroma. Certain key ‘varietal’ aroma compounds such as methoxypyrazines are formed in the grape and appear to be only scarcely influenced by fermentation.