The impact of partial dehydration on grape and wine chemical composition of white grapevine (Vitis vinifera L.) varieties

The aim of this study was to investigate the impact of Double Maturation Raisonnee (DMR) partial dehydration technique on chemical composition of two white and high-yielding grapevine varieties: 'Rebula' and `Vitovska grganja' in two consecutive years. DMR technique was applied, where a cut of one-year old cane two to three weeks before harvest was done and grape remained on the vine till suitable chemical composition was reached. Grape and wine characteristics were monitored along with primary metabolites and phenolic profiles of berry skin and wine. DMR decreased the weight of 100 berries and caused an increase in soluble solids, titratable acidity, individual sugars and organic acids in comparison with the control berries. The wines produced from DMR grapes had higher alcohol content and total extracts. An interesting impact of DMR was observed on phenolic compounds. Procyanidin dimer 1 averagely increased for 22.0 mg kg(-1) in 'Rebula' DMR. berry skin. Similarly, 69.5 mg kg(-1) more quercetin-3-glucoside was determined in 'Vitovska grganja' DMR berry skin compared to the control. In our study, DMR influenced and modified differently but significantly the grape and wine composition, especially the phenolic profiles of two white varieties and contributed to higher wine quality. The results propose the implementation of DMR partial dehydration technique for high-yielding white grapevine varieties in order to produce richer, full-bodied wines.