The chemical composition of disease resistant hybrid grape cultivars and its impact on wine quality: an exploratory enquiry into sustainable wines

In this audio recording of the IVES science meeting 2022, Thibaut Verdenal (Agroscope, Pully, Switzerland) speaks about managing nitrogen balance in cover-cropped vineyard. This presentation is based on an original article accessible for free on OENO One.

The market trend heads to food products with less chemical inputs, including in oenology. During the winemaking process, sulfites are commonly use to avoid microbiological contamination and stabilization of the wine thanks to its antimicrobial and antioxidant activities. Nevertheless, this use is not without consequences on human health and environment, leading for example to allergic reaction and pollution. A biological alternative to these sulfites has emerges: the bioprotection.

Extension of the growing season, compression of the annual growth cycle and higher frequency and severity of weather extreme events are consistent features of global warming. While mitigation of factors causing global warming is necessary in the medium-long term, wine growers need “ready to go” adaptation practices to counteract negative effects bound to climate change. This must be done in a sustainably way, meaning that remunerative yield, desired grape quality, low production cost and environment friendly solutions must be effectively merged. In this work, we will review contribution given over the last two decades prioritizing issues related to scion and rootstock choice, changes in vineyard floor management, new perception related to the use of irrigation in vineyards, adaptation practices aimed at decompress maturity, solutions to counteract or minimize damages due to late frost and sunburn and, lastly, some hints on how precision viticulture can help with all of this.

Bacterial malolactic fermentation (MLF) has a considerable impact on wine quality. The yeast strain used for primary fermentation can consistently stimulate (MLF+ phenotype) or inhibit (MLF- phenotype) malolactic bacteria and the MLF process as a function of numerous winemaking practices, but the molecular evidence behind still remains a mystery. In this study, such evidence was elucidated by the direct comparison of extracellular metabolic profiles of MLF+ and MLF- yeast phenotypes. Untargeted metabolomics combining ultrahigh-resolution FT-ICR-MS analysis, powerful machine learning methods and a comprehensive wine metabolite database, discovered around 800 putative biomarkers and 2500 unknown masses involved in phenotypic distinction.

Wine aroma is shaped by the wine’s chemical compositions, in which both grape constituents and microbes play crucial roles. Although wine quality is influenced by the microbial communities, less is known about their population interactions.