Effect of over crop and reduced yield by cluster thinning on phenolic and volatile compounds of grapes and wines of ‘Sangiovese’ trained to Tendone

Abstract

BACKGROUND ‘Sangiovese’ (Vitis vinifera L.) is a well‐known Italian wine grape utilized for producing the prestigious Chianti Classico brand. Here, ‘Sangiovese’ is generally trained to a vertical training system, with an imposed crop level of around 3–5 kg per vine to preserve grape quality. Tendone comprises a horizontal trellis system, largely diffused in Mediterranean Countries for table grape production, and is adopted to achieve a high yield and to preserve grapes, by means of its canopy architecture, from excessive solar radiation, which in turn affects the organoleptic aspects of grapes and wines. The present study aimed to evaluate, in terms of phenolic and volatile compounds of grape and wines, ‘Sangiovese’ trained to Tendone, as affected by two crop levels, namely very high and reduced yields. RESULTS Reduced yield (18.39 kg per vine) by cluster thinning still appeared to provide a considerable yield and quality of grapes and wines. Thinning increased pH, tartaric acid content, flavonoids, anthocyanins, total polyphenols and proanthocyanins, and total free and bound aroma compounds, without affecting soluble solids and titratable acidity of grapes. As regards wines, reduced yield increased pH, tartaric and malic acids and dry reduced extract, flavonoids, anthocyanins, total polyphenols and proanthocyanins, and, finally, the color intensity of wines. CONCLUSION The present study highlights that Tendone training systems, combined with 40% of cluster thinning, allows a high yield to be reached, allowing, at the same time, a very interesting quality of grapes, making it possible to produce qualitative wines. © 2022 Society of Chemical Industry.

Wine Lees as Source of Antioxidant Molecules: Green Extraction Procedure and Biological Activity

“…Starting from anthocyanins, seven compounds were unequivocally identified—delphinidin-3 O -glucoside, cyanidin-3 O -glucoside, petunidin-3 O -glucoside, peonidin-3 O -glucoside, and malvidin-3 O -glucoside—because of the matching with commercial standards, while peonidin-3 O - trans -coumaroylglucoside (POCG) and malvidin-3 O - trans -coumaroylglucoside (MCG) were identified due to their characteristic chromatographic and spectrophotometric behavior many times reported in the literature [ 14 , 15 ]. Conversely, insufficient information was available to correctly identify the other anthocyanin conjugates in the extracts ( Figure 1 A).…”

“…The tentative identification of the compounds in the extracts was achieved by matching the positions of absorption maxima (λ max ), absorption spectra profiles, and retention times (RT) with those from commercially available pure standards and studies already reported in the literature for comparable matrices [ 14 , 15 ]. Moreover, the quantification was performed using the calibration curves in the concentration range of 100–0.2 µg mL −1 of malvidin-3 O -glucoside (R 2 = 0.9983), caffeic acid (R 2 = 0.9988), epicatechin (R 2 = 0.9944), and gallic acid (R 2 = 0.9991).…”

Viticultural Climate Indexes and Their Role in The Prediction of Anthocyanins and Other Flavonoids Content in Seedless Table Grapes

“…Similar to previous descriptions [29], the "tendone" allows controlling cluster temperature (grape berries were on average 2 • C below ambient), because it improves the canopy management protecting the grapes from direct UV radiation and avoids the sun-burning of berries. Moreover, during the ripening stage, the grapes experience diffuse light that avoids the different coloring between the shaded and the exposed parts of the bunches.…”

Severe Shoot Trimming and Crop Size as Tools to Modulate Cv. Merlot Berry Composition

“…Similar to our study, De Bei et al [29] found that shoot thinning does not improve berry composition when no considerable differences in yield are obtained with this practice. However, if a considerable difference in crop size among treatments is obtained by shoot thinning or cluster thinning, in most cases, the concurrent reduction of both sugar and anthocyanins is obtained with increased yield [51][52][53][54]. In the context of climate change and the associated problems with high sugar concentration in grape berries in warm seasons [2], the practice of increasing yield may be appropriate to reduce the accumulation of sugar in berries, although it may not be convenient if a high intensity of grape and wine color is desired [55].…”