Effects of rootstock and environment on the behaviour of autochthone grapevine varieties in the Douro region

AIM: The aim of this work was to characterize 18 oenological tannins by the polyphenolic, antioxidant, and sensory point of view.

The accession Criolla Chica Nº2 (CCN2) is catalogued as a floral mutation of cultivar Criolla Chica (synonym for cv. Listán Prieto). Contrary to what is observed in hermaphrodite-cultivated varieties like Criolla Chica, CCN2 exhibits a prevalence of masculinized flowers. Aiming to study the incidence and phenotypical implications of this mutation, CCN2 plants were deeply studied using Criolla Chica ‘Ballista’ (CCBA) as control plants. For each CCN2 plant, two inflorescences per shoot were sampled and segmented into proximal, mid and distal positions, relative to the pedicel. Flowers were observed through magnifying lens and classified according to OIV151 descriptor.

Laccases from lactic acid bacteria (LAB) are described as multicopper oxidase enzymes with copper union sites. Among their applications, phenolic compounds’ oxidation and biogenic amines’ degradation, have been described. Besides, the role of LAB in the toxicity reduction of ochratoxin A (OTA) has been reported (Fuchs et al., 2008; Luz et al., 2018). Fungal laccases, but not bacterial laccases, have been screened for OTA and mycotoxins’ degradation (Loi et al., 2018). OTA is a mycotoxin produced by some fungal species, such as Penicillium and Aspergillus sp., which infect grape bunches used for winemaking.

In the pursuit of increasing sustainability, climate change resiliency and independence of synthetic pesticides in agriculture, the interest of consumers and producers in organic and biodynamic farming is steadily increasing. This is in particular the case for the vitivinicultural industry in Europe, where more and more producers are converting from organic to biodynamic farming. However, clear scientific evidence showing that biodynamic farming improves vine physiology, vine stress resilience, berry or wine quality, or is more sustainable for the environment is still lacking although this issue has been addressed by several research teams worldwide.

The alteration in the rainfall pattern and the increase in the temperatures associated to global climate change are already affecting wine production in many viticultural regions all around the world (1). In fact, grapes are nowadays ripening earlier from a technological point of view than in the past, but they are not necessarily mature from a phenolic point of view. Consequently, the wines made from these grapes can be unbalanced or show high alcohol content. Dramatic shifts in viticultural areas are currently being projected for the future (2).