Hyperspectral imaging and machine learning for monitoring grapevine physiology

Las tendencias actuales del mercado apuntan hacia el consumo de vinos con menor contenido en alcohol, y, por otra parte, de vinos con características especiales y diferenciadoras, siendo los vinos con indicación geográfica o denominación de origen los más demandados.

The use of pectinolytic enzymes in winemaking is state of the art. These enzymes catalyse the degradation of pectic substances through depolymerization (hydrolases and lyases) and de-esterification. As a result, it supports the extraction of juice and facilitates filtration. It has also been shown in winemaking that the presence of pectinolytic enzymes improves the stability, taste, texture, colour and aroma of products. With regard to enzymes currently applied in winemaking, enzymes derived from filamentous fungi dominate the enzyme industry. Fungal-based pectinolytic enzymes specifically require purification from the culture medium to eliminate unwanted side reactions, which is poorly sustainable. Some non-traditional yeast strains have been reported to exhibit pectinolytic activities. Therefore, the direct use of pectinolytic yeast during wine fermentation process can be an attractive and alternative source for the use of enzymes as input.

AIM: Vine diseases are still responsible for economic losses. Previous study in our laboratory, have shown effects of oenological tannins against Botrytis cinerea1,2. According to this, the aim was to evaluate the wine protection by oenological tannins against an another disease, the downy mildew. METHODS: During the 2020 vintage, infected grapes by downy mildew (Vitis vinifera cv. Merlot) were collected from the dispositive ResIntBio. The 100 kg were crushed, destemmed and dispatch into 10 aluminium tanks. SO2 was added at 3 g/hL. Oenological tannins (grape, quebracho, ellagitannin or gallotannin) were added at 100 g/hL into eight different tanks (4×2 tanks). The two last tanks were considered as control without addition of oenological tannins. Alcoholic fermentation was achieved with Actiflore 33® at 20 g/hL. Malolactic fermentation was achieved with Lactoenos B7at 1 g/hL. Finished wines were sulfited to obtain 45 mg/L of total SO2.

Right after the pouring of champagne in a glass, thousands of rising and bursting bubbles convey gas-phase CO2 and volatile organic compounds in the headspace above the champagne surface, thus progressively modifying the gaseous chemical space perceived by the consumer [1]

Most vineyards are grafted and include a variety (Vitis vinifera) grafted over a wild Vitis rootstock (hybrids of V. berlandieri, riparia and rupestris). Grape berry quality at harvest depends on a subtle balance between acidity and the concentrations of sugars, polyphenols and precursors of aroma compounds. The mechanisms controlling the balance of sugars/acids/polyphenols are influenced by the abiotic environment, in particular nitrogen supply, and interact with the genotypes of both the scion variety and the rootstock. Previous work suggests that some of the effects of water stress are in fact linked to a nitrogen deficiency driven indirectly by the reduction of water absorption.