The beneficial effect of leaf removal during fruit set on physiological, biochemical, and qualitative indices and volatile organic compound profile of the Cypriot reference cultivar ‘Xynisteri’

Abstract

Background ‘Xynisteri’ is the reference Cypriot white cultivar that, despite its significant societal and economic impact, is poorly characterized regarding its qualitative properties, while scarce information exists regarding its aroma profile. In the current study, the effect of leaf removal during fruit set (BBCH 71) on 6‐year cordon‐trained, spur‐pruned grapevines was assessed and an array of physiological, biochemical, and qualitative indices were monitored during successive developmental stages (BBCH 75, BBCH 85, BBCH 87, and BBCH 89). Grapes were additionally monitored for the volatile organic compounds (VOCs) profile during the advanced on‐vine developmental stages (BBCH 85–BBCH 89) with the employment of gas chromatography–mass spectrometry (GC–MS), Fourier‐transform near infrared (FT‐NIR) spectra and electronic nose (E‐nose) techniques. Results Grape berries from the vines subjected to leaf removal were characterized by higher solid soluble sugars (SSC), titratable acidity (TA), tartaric acid, and ammonium nitrogen contents, while this was not the case for assimilable amino nitrogen (primary amino nitrogen). A total of 75 compounds were identified and quantified, including aliphatic alcohols, benzenic compounds, phenols, vanillins, monoterpenes, and C13‐norisoprenoids. Leaf removal led to enhanced amounts of glycosylated aroma compounds, mainly monoterpenes, and C13‐norisoprenoids. Chemometric analysis, used through FT‐NIR and E‐nose, showed that the aromatic patterns detected were well associated to the grape ripening trend and differences between leaf removal‐treated and control grapes were detectable during fully ripe stage. Conclusion Leaf removal at fruit set resulted in an overall induction of secondary metabolism, with special reference to glycosylated aroma compounds, namely monoterpenes and C13‐norisoprenoids. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Metabolite profiling reveals the influence of grapevine genetic distance on the chemical signature of juices

“…‘Marselan’, the contents of LOX‐derived volatiles 2‐heptanol, cis ‐7‐decenal, and trans ‐2‐hexenal were not significantly influenced by shading, although the expression levels of genes encoding LOX oxidases, fatty acid hydroperoxide lyases, and alcohol dehydrogenases were shown to be highly correlated with volatile contents 50 . In contrast, leaf removal during fruit set increased the contents of monoterpenes and C 13 ‐norisoprenoids in ‘Xynisteri’ grapes, a traditional vinifera cultivar from Cyprus 51 …”

“…50 In contrast, leaf removal during fruit set increased the contents of monoterpenes and C 13norisoprenoids in 'Xynisteri' grapes, a traditional vinifera cultivar from Cyprus. 51 Recently, plant phenotyping has incorporated high-throughput metabolomics to genetic and system biology studies to bridge the gap between the genome and the phenotype. 52 UHPLC-MS is considered a powerful tool and a comprehensive analytical approach in plant metabolomics due to its ability to separate metabolites in the liquid phase without pre-treatment.…”

Effect of Cluster-Zone Leaf Removal at Different Stages on Cabernet Sauvignon and Marselan (Vitis vinifera L.) Grape Phenolic and Volatile Profiles

“…Several studies have demonstrated the diverse effects of cluster-zone leaf removal on grape volatile compounds, with the effects varying depending on the grape variety, climate, treatment stage, and intensity. Most of these studies have indicated that the removal of leaves has the effect of promoting the synthesis of monoterpenes, specifically α -terpineol and linalool, and their oxidised derivatives [ 10 , 11 , 14 ]. One study observed an increase in the total amount of monoterpenes in the group with 50% leaf removal during veraison, while no significant difference was observed in the group with 100% defoliation [ 8 ].…”

“…Furthermore, leaf removal during the pepper-corn-size stage and veraison resulted in a reduction in the total terpene content in an intensely light, dry–hot climate [ 15 ], indicating that overexposure could have a negative impact on terpene accumulation. A number of studies have indicated that leaf removal from the cluster zone can lead to increased levels of norisoprenoids [ 11 , 14 , 16 ]. This is thought to be linked to increased synthesis of carotenoids [ 10 ].…”

Recent Advances and Future Perspectives in the E-Nose Technologies Addressed to the Wine Industry

“…A QMB-based E-Nose combined with volatilome analysis has also been tested with the aim of discriminating sparkling wines obtained under different temperature and yeast conditions [88]. The QMB E-nose can also be used to monitor how vine leaf removal may affect the aromatic compounds of the grape berries [104]. It has been found that the application of these non-destructive tools with MOS sensors seems to be widely studied for its aptitude to compare different wines coming from different vintages, even identifying the wine quality [101][102][103]122].…”