Can wine composition predict quality? A metabolomics approach to assessing Pinot noir wine quality as rated by experts

AIM: Agiorgitiko (Vitis vinifera L. cv.) is the most cultivated red grapewine variety in Greece1 located mainly in Nemea region, the largest PDO zone in Greece2. Although Agiorgitiko is considered as one of the most interesting red grape varieties, not only in Greece3, but also at international level4,5, however, there is a lack of knowledge

G.r.a.s.p.o. Is not only the acronym for gruppo di ricerca per la salvaguardia e preservazione dell’originalità viticola di ogni territorio (‘research group for the safeguard and preservation of the originality of every territory’s grapes’), and is not just the italian synonym for ‘raspo’ (‘peduncle’) as treccani dictionary mentions: in the veneto dialect it is the whole bunch of grapes.

The amount of synthetic pesticides applied in viticulture is relatively high compared to other agricultural crops, due to the high sensitivity of grapevine to diseases such as downy mildew (Plasmopora viticola). Alternatives to reduce fungicides are utterly needed to promote a sustainable vineyard-ecosystems and meet consumer acceptance. Essential oils (EOs) are amongst the most promising natural plant protection agents and have shown their antifungal properties previously. However, the efficiency of EOs depends highly on timing and application technique.

From a fertility standpoint, the vine has to extract from the soil mineral substances necessary for its existence. However, the amount of certain available nutrients does not always correspond to a proportional increase in quality.

Nitrogen (N) uptake by grapevine roots in forms like nitrate, ammonium, urea, or amino acids influences vegetative and generative growth, impacting grape quality and wine sensory profile. The study examined nitrogen’s influence on phenolic compounds in leaves, berries, and wine across different scales — hydroponics, soil culture, and vineyard trials. Nitrogen forms altered metabolite patterns in leaves and wine significantly, affecting aroma and flavor. Key nitrogen assimilation enzymes (NR, NiR, GS) in grapevine rootstocks responded to nitrogen forms and timing. Hydroponically grown rootstocks fertilized with various forms showed differences in enzyme expression and activity, suggesting rootstocks can assimilate amino acid glutamine (Gln).