Effect of early leaf removal on Vitis Vinifera L. cv. Tempranillo seeds during ripening based on chemical and image analysis

• Effect of early leaf removal was studied in seed ripening in cv. Tempranillo (Spain).
• Phenolic compounds, colorimetric and morphological parameters were determined.
• Advance of maturation, and smaller and darker seeds were caused by ELR.
• Variables obtained by image analysis could predict chemical composition.
• Image analysis could be useful in studies of seed maturation.

Phenolic composition, colour and morphology variables were monitored during ripening in grape seeds of Vitis vinifera L. cv. Tempranillo in 2010. The aim of the study was to determine the effect of limitation induced by early leaf removal (ELR) vs. non-defoliated (ND) control vines. The ultimate goal of this research was to assess whether phenolic composition could be predicted based on variables obtained by image analysis. ELR advanced grape maturity also had lower phenolic concentration and smaller and darker seeds. (+)-Catechin and total cinnamic acid contents as well as L* and aspect ratio were the most significant parameters for distinguishing treatments. Furthermore, area, length, width, L*, a*, b* and heterogeneity predict the phenolic composition in grape seeds. Although it is not yet a substitute for chemical analysis, it could become a quick way to estimate the phenolic composition of grape seeds during maturation. The methodology proposed in this work could be a powerful tool for winemakers.

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