Study of the sensory dimension of the wine typicality related to a terroir and crossing with their viticultural and oenological characteristics

Must clarification is an important step occurring just after grape extraction in the elaboration of white wine, consisting in a solid-liquid separation. Traditionally, low must turbidity, around 50-150 NTU, is generally reached in white winemaking in order to prevent reductive aromas and facilitating alcoholic fermentation. Alternatively, a higher turbidity (300 NTU or above) can be sought for reasons such as a better expression of grapes identity (terroir), or for getting a must matrix that could supposedly lead to wines having greater ageing potential.

Most of the effects of ultrasound (US) result from the collapse of bubbles due to cavitation. The shockwave produced is associated with shear forces, along with high localised temperatures and pressures. However, the high-speed stream, radical species formation, and heat generated during sonication may also affect the stability of some enzymes and proteins, depending on their chemical structure. Recently, Ce-lotti et al. (2021) reported the effects of US on protein stability in wines. To investigate this further, the effect of temperature (40°C and 70°C; 60s), sonication (20 kHz and 100 % amplitude, for 20s and 60s, leading to the same temperatures as above, respectively), in combination with Aspergillopepsins I (AP-I) supplementation (100 μg/L), was studied on unstable protein concentration (TLPs and chitinases) using HPLC with an UV–Vis detector in a TLPs-supplemented model system and in an unstable white wine.

Climate change is affecting wine production and inducing significant variability in wine composition between vintages.

The selection, characterization, and recruitment of autochthonous yeast strains to drive the alcoholic fermentation process is a highly researched practice because it allows the differentiation of the organoleptic properties of wines, assuring process standardization, reducing fermentation times and improving the quality and safety of the final products [1, 2]. Sparkling wines are “special wines” obtained by secondary fermentation of the base wine. ​In the traditional method (Champenoise method), the re-fermentation takes place in the bottle after the addition to the base wine of the so-called tirage solution. This step, also known as prise de mousse, is followed by an aging period characterized by the release of compounds from the yeast cells that affect the organoleptic properties of the final product. The use of autochthonous yeasts as starter cultures for secondary fermentation is one of the recent innovations proposed to enhance and differentiate these wines’ sensory quality [3,4]. Apulia is the second Italian wine-producing region, and its productive chain is now going through a qualitative evolution by implementing the employment of innovative approaches to exalt the peculiar properties of regional wines.

Wines with tropical fruit aromas have become increasingly more available1,2. With increased availability of different wine styles, it has become important to understand the compounds that cause the fruity aromas in wine. Previous work using micro fermentations showed that fermentation temperature gradients and time on skins resulted in an increase in thiol and ester compounds post fermentation and these compounds are known to cause tropical fruit aroma in wines³. This work aimed to scale up these fermentations/operations to determine if the desired 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.