Delayed ripening affects the formation of berry quality traits in ‘Cabernet Sauvignon’ grapes

P. Previtali, N. Dokoozlian, L. Sanchez, B. Pan, K. Wilkinson, C. Ford
In response to extremes of heat and drought, grape berry sugar accumulation has been shown to accelerate, resulting in the desynchronization between primary and secondary berry metabolites. The development of cultural practices to reduce the rate of sugar accumulation during ripening has been advocated in order to re-synchronize sugar accumulation with the accumulation of berry constituents responsible for wine aroma, mouthfeel and color. Experimental treatments (cluster thinning and late season irrigation) were used to obtain fruit ripening rates that were faster and slower than the control. The effect on the accumulation of primary and secondary metabolites was characterized through a sequential sampling approach. Delayed fruit ripening, as measured by reduced sugar accumulation rates, had negligible effects on the concentrations of organic acids, which were mainly responsive to the maturity stage. The phenolic composition of grapes was either unchanged or positively impacted by delayed ripening, suggesting benefits to wine color and mouthfeel. Slowing down ripening also improved grape aroma composition, decreasing the concentration of compounds responsible for undesirable green aromas while increasing desired fruit aromas, volatiles and glycosides. These data further demonstrate the importance of controlling berry ripening rate in order to increase the value and winemaking potential of grapes grown under the warmer and drier conditions associated with a changing climate.
Previtali, P., Dokoozlian, N., Sanchez, L., Pan, B., Wilkinson, K. and Ford, C. (2024). Delayed ripening affects the formation of berry quality traits in ‘Cabernet Sauvignon’ grapes. Acta Hortic. 1390, 153-160
DOI: 10.17660/ActaHortic.2024.1390.19
delayed ripening, fruit composition, grape quality, organic acids, phenolic compounds

Acta Horticulturae