The light exposure of wine can be detrimental as a relevant loss of aromas takes place [1] and light-induced reactions can occur. The latter involves riboflavin (RF), a photosensitive compound, that is fully reduced by acquiring two electrons. When the electron-donor is methionine, the light-struck taste (LST) can appear leading to cooked cabbage, onion and garlic odours-like [2]. The use of oenological tannins can limit the appearance of LST in both model wine [3] and white wine [4]. This research aimed to evaluate the impact of certain oenological tannins, selected in a previous study as the most effective against LST [5], in both white and rosé wines.

Many fleshy fruit, including the grape berry, exhibit a double‐sigmoid growth (DSG) pattern. Identification of the curious DSG habit has long been attributed to Connors’ (1919) work with peaches

Oenological tannins are products extracted from various botanical sources, such as mimosa,
acacia, oak gall, quebracho, chestnut and tara. The polyphenolic component is obtained through a solid-liquid extraction also using specific solvents, then removed by evaporation or freeze-drying. Tannins are employed in two phases of winemaking, during the pre-fermentative phase or during fining with different purposes such as modulate antioxidant activity, colour stabilization, bacteriostatic activity, protein stabilization and modulation of sensory properties. To date, the current regulatory framework is not very clear. In fact, the Codex Alimentarius classifies commercial tannins as “food additives” but also as
“processing aids”. The main distinction is that “additives” have a technological function in the final food, whereas “processing aids” do not. In this sense, oenological tannins, despite the technological treatments, could contain aromatic compounds of the botanical species they belong to and release them to the wine.

Chitin is the main structural component of a large number of organisms (i.e., mollusks, insects, crustaceans, fungi, algae), and marine invertebrates including crabs and shrimps. The main derivative of chitin is chitosan (CH), produced by N-deacetylation of chitin in alkaline solutions. Over the past decade, the OIV/OENO 338A/ 2009 resolution approved the addition of allergen-free fungoid CH to must and wine as an adjuvant for microbiological control, prevention of haziness, metals chelation and ochratoxins removal (European Commission. 2011). Despite several studies on application of CH in winemaking, there are still very limited and controversial data on its interaction with acidic components in wine (Colan-gelo et al., 2018; Castro Marin et al., 2021).

The ongoing climate change results in increasing mean air temperature, which is manifested by weather extremes or sudden changes between drought and local heavy rainfalls. These changing conditions are especially challenging for the established grapevine varieties growing under cool climate conditions due to an increased biotic infection pressure. Thus, the scope of most grapevine breeding programs is the selection of mildew fungus-resistant and climatic adapted grapevines with balanced, healthy yield and outstanding wine quality. Since no resistances or candidate genes have yet been described for Botrytis bunch rot (BBR), physical-mechanical traits like berry size and thick, impermeable berry cuticles phenotyped with high-throughput sensors represent novel effective parameters to predict BBR.