Variations of soil attributes in vineyards influence their reflectance spectra

The development of non-animal and non-allergenic alternatives to traditional protein fining agents used in winemaking is of critical importance in order to ensure consumer safety and production sustainability. This study evaluates the effect of protein extracted from three types of algae (spirulina, chlorella vulgaris and tetraselmis chuii) as fining agents on the polymeric proanthocyanidin content responsible for astringency, as well as their effect on the colour, phenolic composition and volatile aroma of two white wines (a and b).

The evolution of wine during bottle ageing has been of great interest to ensure consistent quality over time. While the role of wine closures on the amount of oxygen is well-known [1], closures could also play other roles such as the scalping phenomenon of flavour compounds. Flavour scalping has been described as the sorption of flavour compounds by the packaging material, which could result in losses of flavour intensity. It has been reported in the literature that volatile sulphur compounds (VSC) can be scalped on wine closures depending on the type of closure (traditional and agglomerated cork, screw-cap, synthetic [2]).

Brazil is historically known at the international wine market as an importer, eventhough in the last decades there was an increase in quantity and quality of the internal production. Nowadays, about 40% of fine wines comsuption of the country are national ones. The main production region is called Serra Gaúcha, where the natural conditions are heterogeneous and viticulture is develloped in small properties, mainly done by the owners family.

Located in the western bekaa region of lebanon, rachaya is known for its extensive history of viticulture and ideal mediterranean conditions for grapevine cultivation. Despite the area’s importance in grapevine production, there is limited knowledge about the local grape varieties grown there. In this work, we conducted a detailed analysis of five local grapevine varieties in the area, obeidy, kassoufi, foddeh, aswadi, and maryami, of which little is currently known, in comparison to a set of international varieties.

Grape harvest time is one of the most fundamental aspects that affect grape quality and thus wine quality. Many factors influence the decision of harvest; among them technological and phenolic maturity of grape. Technological ripeness is mainly related to sugar concentration, titratable acidity and pH. Conventional methods for chemical analysis of grapes are normally sample-destructive, time-consuming, include laborious sample preparation steps, and generate chemical waste, thereby limiting their utility in online/in-line quality monitoring. Moreover, destructive analyses can be performed only on a limited number of fruit pieces and, thus, their statistical relevance could be limited. This study evaluated the ability of a lab-scale hyperspectral imaging (HYP-IM) technique to predict titratable acidity, organic acid and sugar content of grapes. Samples of Cabernet franc and Chenin blanc grapes were consecutively collected six times at weekly intervals after veraison. The images were recorded thanks to the hyperspectral imaging camera Pica L (Resonon) in a spectral range from 400 to 1000 nm. Statistics were performed using Microsoft Xlstat software. Successively, the berries were analyzed for their sugar (glucose and fructose) and organic acid (malic and tartaric acid) content and titratable acidity according to usual methods.