Photoprotective extracts from agri-food waste to prevent the effect of light in rosé wines 

Atmospheric CO2 levels have been rising continuously since the industrial revolution, affecting crop physiology, yield and quality of harvest products, and grapevine is no exception [1]. Most of previously reported studies used potted plants in controlled environments, and explored grapevine response to relatively high CO2 levels, 700 ppm or more. The vineyardFACE, established in Geisenheim in 2012, uses a free air carbon dioxide enrichment (FACE) system to simulate a moderate (ambient +20%) increase in atmospheric CO2 in a vineyard planted with cvs. Cabernet-Sauvignon and Riesling grafted on rootstock 161-49 Couderc and SO4, respectively.

Climate change has numerous detrimental consequences and creates new challenges for viticulture around the world. Transitory or constant high temperatures frequently associated with an excess of sunlight (UV) can cause a variety of physiological disorders, such as sunburn. Diverse environmental factors and the plant’s response mechanisms to stress determine the symptoms. Grapevine berry sunburn leads to a drastic reduction in yield, and may eventually decline berry quality. Consequently, this poses a significant risk to the winegrowers.

Antagonistic yeasts applied to wine grapes must be compatible with the thereafter winemaking process, avoiding competition with the fermentative Saccharomyces cerevisiae or affecting wine flavour. Therefore, fifteen epiphytic yeasts (6 Metschnikowia sp., 6 Hanseniaspora uvarum, 3 Starmerella bacillaris) previously selected for its biocontrol ability against Alternaria on wine grapes were evaluate for possible competition with S. cerevisiae by the Niche Overlap Index (NOI) employing YNB agar media with 10 mM of 17 different carbonate sources present in wine grapes (proline, asparagine, alanine, glutamic acid, tirosine, arginine, lisine, methionine, glicine, malic acid, tartaric acid, fructose, melibiose, raffinose, rhamnose, sucrose, glucose).

Tropical fruit aromas in wines are thought to be important to wine consumers, although there is little research to confirm this statement. With so many wine styles available, it has become important to understand the qualities that are desirable to consumers and how to achieve those qualities. Thiols and esters are compounds that have been found to cause tropical fruit aromas in chardonnay (ref). Fermentation temperature gradients and skin contact were found to increase these compounds using micro scale fermentations. This work aimed to scale up these fermentations/operations to determine if the desired tropical fruit aromas could still be achieved and if there is a perceivable difference in tropical fruit aromas, liking, and emotional response in the wines at the consumer level.

The context of climate crisis leads to the acceleration of technological ripening of grapes, with unsuitable loss of acidity, so various vineyard management alternatives are being considered to delay the grape ripening. The delay of the vegetative cycle towards a period of milder temperatures affects ripening, but vine behavior can vary according to the area, conduction, watering, variety, etc. A work is proposed to know the response to the green pruning of shoots, executed in fruit set and in pea size, in cv. Verdejo.