Application of UV-B radiation in pre- and postharvest as an innovative and sustainable cultural practice to improve grape phenolic composition

The definition of soil health is complex due to the lack of agreement on adequate indicators and to the high variability of global soils. Nevertheless, it has been widely used as synonymous of soil quality for more than one decade, and there is a consensus warning of scientists that soil quality and biodiversity loss are occurring due to the traditional intensive agricultural practices.
In this work we monitored a set of soil parameters, both physicochemical and microbiological, in an experimental vineyard under three different management and land use systems: a) addition of external organic matter (EOM) to tilled soil; b) no tillage and plant cover between grapevine rows, and c) grapevines planted in rows running down the slope and tilled soil.

Understanding grapevine molecular processes and the underlying defence responses is vital for developing sustainable disease control strategies. Lipid signalling pathways, involving the synthesis and degradation of lipid molecules, have emerged as a key regulator in plant defence against pathogens. This study aims to elucidate the role of fatty acids and lipid signalling in grapevine’s defence response to P. viticola infection. The expression of lipid metabolism-related as well as lipid signalling genes was analysed, by qPCR, in three grapevine genotypes: Chardonnay (susceptible), Regent (tolerant) with Rpv3-1 resistance loci, and Sauvignac (resistant) harbouring a pyramid of Rpv12 and Rpv3-1 resistance loci.

Wine is the result of the alcoholic fermentation (AF) of grape must. Besides AF, wine can also undergo the malolactic fermentation (MLF) driven out by lactic acid bacteria (LAB). Among LAB, Oenococcus oeni and Lactiplantibacillus plantarum are the dominant species in wine. Even if O. oeni is the most common LAB undergoing MLF in wine, due to its high tolerance to wine conditions, L. plantarum can be used to undergo MLF in must. The moderate tolerance of L. plantarum to low pH and ethanol, may compromise the fermentative process in harsh wines.

In order to study the impact of climate change on Bordeaux grape varieties and to assess the behavior of candidate grape varieties potentially better adapted to the new climatic conditions, an experimental vineyard composed of 52 grape varieties was planted in 2009 at the INRAE Bordeaux Aquitaine center[1]. Among the many parameters studied since 2012, berry weight for each variety was measured weekly from mid-veraison to maturity, with four independent replicates. The kinetics obtained allowed to study berry growth, a key parameter in grape composition and yield.

The presence of acetic acid bacteria in wine can lead to the appearance of acetic acid at concentrations above the perception threshold, causing the wine rejection by the consumer. During the winemaking process, avoiding the presence of acetic acid bacteria is very difficult, as there is always a residual population accompanying the wine[1], and the problem arises with the significant development of these microorganisms that metabolizes large amounts of acetic acid.
The concern of wineries to control the presence of acetic acid bacteria in wines during their conservation is due to the absence of simple and effective analyses that allow the detection of these microorganisms in the initial stages.