Grape aroma precursors in cv. Nebbiolo as affected by vine microclimate.
The influence exerted by bunch microclimate on some C13-norisoprenoid precursors content was investigated for the first time in Nebbiolo grapes during ripening. Samples were collected, during two consecutive seasons, from two vineyards, which are characterized by different microclimatic conditions caused by vine vigour heterogeneity and different vineyard aspects. Enzymatic hydrolysis of the glycosides extracted from the grapes, and subsequent GC-MS determination of the aglycones, highlighted that the majority of norisoprenoid glycosides accumulated in Nebbiolo berries from pre-veraison until 3-4weeks post-veraison. Vineyard aspect and vine vigour affected the timing of the maximum concentration of norisoprenoid precursors and their subsequent decrease at harvest. Low light in the vigorous blocks penalized norisoprenoids peak concentration. In the south less vigorous blocks, a decline of total norisoprenoids content during the pre-harvest period was observed. This decline appeared mainly regulated by the temperature. Vintage and/or microclimatic conditions affected the final content of some important norisoprenoids.
Consiglio per la ricerca e l'analisi dell'economia agraria - Centro di Ricerca per l'Enologia, Via P. Micca, 35, 14100 Asti, Italy.
Andriani
A
Asproudi
Consiglio per la ricerca e l'analisi dell'economia agraria - Centro di Ricerca per l'Enologia, Via P. Micca, 35, 14100 Asti, Italy. Electronic address: maurizio.petrozziello@entecra.it.
Maurizio
M
Petrozziello
Dipartimento di Scienze Agrarie, Forestali e Alimentari (Università di Torino), Largo Braccini, 2, 10095 Grugliasco, Italy.
Silvia
S
Cavalletto
Dipartimento di Scienze Agrarie, Forestali e Alimentari (Università di Torino), Largo Braccini, 2, 10095 Grugliasco, Italy.
Silvia
S
Guidoni
D008834:Microclimate; D012903:Smell; D027843:Vitis / Q000737:chemistry*
C(13)-norisoprenoids; Nebbiolo; Ripening; Vine vigour; Vineyard aspect; Vitis vinifera