The SIFT-MS fingerprint of Vitis vinifera L. cv. Syrah berries is stable over the second part of maturation under warm conditions of climate

Wine grape breeding for fungal resistance has been very dynamic worldwide over the last decade. The quick phenotyping of genotype quality traits, including aroma composition, remains challenging. Selected ion flow tube mass spectrometry (SIFT-MS) could be particularly valuable for this usage. Due to the high number of seedlings to phenotype and the low availability of berries, the sampling strategy can hardly rely on time-consuming destructive methods such as the measurement of classical maturity parameters (i.e., sugar concentration). To investigate the impact of the sampling time on the SIFT-MS fingerprint, berries from Vitis vinifera L. Syrah were collected in 2020, a season characterised by warm climatic conditions, at seven times during maturation and analysed by SIFT-MS using O-2(+) as reagent ion. This fingerprint has proved to be stable from 28 days after mid-veraison. This finding greatly simplifies the sampling procedure for future berry phenotyping, which can only rely on non-destructive data (lapse of time after mid-veraison date). For most m/z, a decrease in abundance was observed during the maturation, which could be the consequence of volatile emission or an increase in non detectable bound compounds. Further studies would be necessary to assess the full grape aroma potential, to better understand the mechanisms involved, and to evaluate our approach over more than one season.