Study of Intact Glycosidic Aroma Precursors in Recovered Minority White Grape Varieties under Water Stress Conditions

TL;DR

This study examines how water stress affects the aroma precursor composition in two minor white grape varieties and compares them to a dominant regional cultivar.

Contribution

The study identifies varietal-specific aroma precursor responses to water stress and potential markers for Pintada, Jarrosuelto, and Airén grape varieties.

Findings

Pintada showed enhanced accumulation of aroma precursors under severe water stress.

A C13-norisoprenoid hexose–hexose derivative was found exclusively in Airén.

An isopropyl alcohol pentosyl-hexoside isomer was detected only in Jarrosuelto.

Abstract

The identification of viticultural strategies capable
of mitigating
the effects of climate change, including increased temperatures and
reduced water availability, has prompted renewed interest in minor
grapevine varieties adapted to specific growing areas. The enological
suitability of these cultivars depends, in part, on the characterization
of their glycosylated aroma precursors. In this study (2022 harvest),
two recovered white grape varieties from Castilla–La Mancha,
Pintada and Jarrosuelto, were evaluated. Their adaptability to two
water stress regimes (moderate/deficit and severe/survival) was evaluated
through the composition of intact aroma precursors compared with the
predominant regional cultivar, Airén. The results revealed
cultivar-dependent responses to water stress. Aroma precursor biosynthesis
in Airén was only marginally affected, whereas Pintada exhibited
enhanced accumulation under severe water deficit. Additionally, a
C13-norisoprenoid hexose–hexose derivative and an
isopropyl alcohol pentosyl-hexoside isomer were detected exclusively
in Airén and Jarrosuelto, respectively, indicating their potential
as varietal markers.

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