Selected-Ion Flow Tube Mass Spectrometry: A high-throughput technology to investigate the impact of climate and harvest date on the volatilome of Grenache berries

Abstract

Climate change is increasingly affecting wine production, leading to substantial variations in wine composition from one vintage to another. Changes in precipitation patterns and higher temperatures during maturation often disrupt the balance between technological and phenolic ripening (van Leeuwen et al., 2024). These disturbances can result in delayed maturation, elevated sugars, and the emergence of aroma defects at harvest. Grenache, a cultivar extensively grown in France and Spain, particularly in the foothills of the Pyrenees, is especially susceptible to these climate-induced effects. This study aimed to assess the impact of climate and grape maturity on the volatilome of Grenache berries using Selected-Ion Flow Tube Mass Spectrometry (SIFT-MS) technology. For the major Grenache-producing PDOs in Pyrénées-Orientales, Aragon, Navarra, and La Rioja, historical climate data spanning 1981–2010 were collected to calculate several bioclimatic indices. K-means clustering was then applied to classify vineyards into three homogeneous climatic zones. Using a stratified sampling approach, 28 vineyards were selected across France and Spain (20 in Spain, 8 in France) to represent these isoclimatic zones. At each vineyard, grape samples were collected in 2024 at three maturity stages: the first (P1) at 21.0 ± 2.0 °Brix, the second (P2) 10–14 days later, and the third (P3) 10–14 days after P2. Forty grams of berries were analysed in only two minutes using the previously described protocol with O₂⁺ as reagent ion (Baerenzung et al., 2022). A multi-step statistical pipeline was applied, including one-way ANOVAs to identify discriminant ions, Principal Component Analysis (PCA) to examine the clustering of samples, two-way ANOVAs to determine which factors most strongly influenced the volatilome, and finally, classification and regression tree (CART) analysis to identify ions predictive of isoclimatic zone or harvest date. Of 201 detected ions, 111 contributed to discriminating the samples. PCA indicated that samples clustered primarily according to harvest date, a finding supported by the fact that abundances of 92 m/z ratios were significantly affected by harvest date, compared to only one ion by isoclimatic zone. Ion abundances were in most cases higher at P1, which is consistent with previous research (Geffroy et al., 2022). The CART model performed better at predicting harvest dates (84% correct classification) than isoclimatic zones (76%). Notably, m/z 170 potentially corresponding to a known marker of overmaturation namely 3-methyl-2,4-nonanedione, enabled to discriminate P2 from P3, which could convert SIFT-MS into a high-throughput tool for detecting aroma defects.

References

Baerenzung dit Baron, T., Yobrégat, O., Jacques, A., Simon, V., & Geffroy, O. (2022). A novel approach to discriminate the volatilome of Vitis vinifera berries by selected ion flow tube mass spectrometry analysis and chemometrics. Food Research International, 157, 111434. https://doi.org/10.1016/j.foodres.2022.111434

Geffroy, O., Baerenzung dit Baron, T., Yobrégat, O., Denat, M., Simon, V., & Jacques, A. (2022). The SIFT-MS fingerprint of Vitis vinifera L. cv. Syrah berries is stable over the second part of maturation under warm conditions of climate. OENO One, 56(4), 139-146. https://doi.org/10.20870/oeno-one.2022.56.4.7066

van Leeuwen, C., Sgubin, G., Bois, B., Ollat, N., Swingedouw, D., Zito, S., & Gambetta, G. A. (2024). Climate change impacts and adaptations of wine production. Nature Reviews Earth & Environment, 5(4), 258-275. https://doi.org/10.1038/s43017-024-00521-5