Overhead photoselective shade films mitigate effects of climate change by arresting flavonoid and aroma composition degradation in wine

Lauren E Marigliano; Runze Yu; Nazareth Torres; Cristina Medina-Plaza; Anita Oberholster; Sahap Kaan Kurtural

doi:10.3389/fpls.2023.1085939

Overhead photoselective shade films mitigate effects of climate change by arresting flavonoid and aroma composition degradation in wine

Front Plant Sci. 2023 Jan 27:14:1085939. doi: 10.3389/fpls.2023.1085939. eCollection 2023.

Authors

Lauren E Marigliano¹, Runze Yu¹, Nazareth Torres¹, Cristina Medina-Plaza¹, Anita Oberholster¹, Sahap Kaan Kurtural¹

Affiliation

¹ Department of Viticulture and Enology University of California, Davis, Davis, CA, United States.

Abstract

Introduction: Overhead photoselective shade films installed in vineyards improve berry composition in hot grape-growing regions. The aim of the study was to evaluate the flavonoid and aroma profiles and composition of wines from Cabernet Sauvignon grapes (Vitis vinifera L.) treated with partial solar radiation exclusion.

Methods: Experimental design consisted in a randomized experiment with four shade films (D1, D3, D4, D5) with differing solar radiation spectra transmittance and compared to an uncovered control (C0) performed over two seasons (2021 and 2022) in Oakville (CA, USA). Berries were collected by hand at harvest and individual vinifications for each treatment and season were conducted in triplicates. Then, wine chemical composition, flavonoid and aromatic profiles were analyzed.

Results: The wines from D4 treatment had greater color intensity and total phenolic index due to co-pigmentation with anthocyanins. Shade film wines D5 and D1 from the 2020 vintage demonstrated increased total anthocyanins in the hotter of the two experimental years. In 2021, reduced cluster temperatures optimized total anthocyanins in D4 wines. Reduced cluster temperatures modulated anthocyanin acylation, methylation and hydroxylation in shade film wines. Volatile aroma composition was analyzed using gas chromatography mass spectroscopy (GCMS) and D4 wines exhibited a more fruity and pleasant aroma profile than C0 wines.

Discussion: Results provided evidence that partial solar radiation exclusion in the vineyard using overhead shade films directly improved flavonoid and aroma profiles of resultant wines under hot vintage conditions, providing a tool for combatting air temperatures and warmer growing conditions associated with climate change.

Keywords: C13-norisoprenoids; anthocyanins; climate change; esters; flavonols; ketones.

Grants and funding

Part of the publishing fees for this paper has been defrayed by University of California Davis library. A graduate student stipend was provided to LEM from University of California Davis during the execution of the trial.