Laura Farris

Rootstocks play a crucial role in viticulture because of both their agronomic benefits and impact on grape and wine chemical composition. Their influence on vigor, yield, and phenolic maturity has been widely studied, but only recently have studies begun to examine their effects on wine aroma compounds and sensory profiles. This review compiles findings of studies investigating 33 rootstocks for their influence on wine aroma composition and 29 rootstocks for sensory evaluation across 10 red and four white grape varieties. The most studied rootstocks include 1103 Paulsen, 110 Richter, Sélection Oppenheim 4 and 101-14 Millardet et de Grasset. Shiraz, Merlot, and Cabernet-Sauvignon are the most frequently assessed varieties. Despite growing works in this research area, results are highly variable due to differences in experimental design, winemaking protocols, and sensory methodologies. Only five studies have simultaneously analyzed both wine aroma compounds and sensory attributes. While some consistent trends emerge for certain aroma compounds, such as β-damascenone or linalool, most findings remain context-dependent. This review emphasizes a lack of standardization, including that of winemaking conditions, and highlights the critical need for multi-site, multi-year studies to better understand rootstock effects on wine aroma and sensory quality.

Nowadays, the use of sulfur dioxide (SO₂) during the winemaking process is a controversial societal issue. In order to reduce its use, various alternatives are emerging, in particular bioprotection by adding yeasts, with different impacts on yeast microbiota in early winemaking stages. In this study, quantitative-PCR and metabarcoding high-throughput sequencing (HTS) were combined with MALDI-TOF-MS to monitor yeast population dynamic and diversity in the early stages of red winemaking process without sulfites and with bioprotection by Torulaspora delbrueckii and Metschnikowia pulcherrima addition. By using standard procedures for yeast protein extraction and a laboratory-specific database of wine yeasts, identification at species level of 95% of the isolates was successfully achieved by MALDI-TOF-MS, thus confirming that it is a promising method for wine yeast identification. The different approaches confirmed the implantation and the niche occupation of bioprotection leading to the decrease of fungal communities (HTS) and Hanseniaspora uvarum cultivable population (MALDI-TOF MS). Yeast and fungi diversity was impacted by stage of maceration and, to a lesser extent, by bioprotection and SO₂, resulting in a modification of the nature and abundance of the operational taxonomic units (OTUs) diversity.