Influence of viticulture practices on grape aroma precursors and their relation with wine aroma.
BACKGROUND
The effects of two different operations in the vineyard (basal leaf plucking and head trimming) on the synthesis of aromatic precursors in the grape and their impact on wine aroma have been studied and compared with a control sample. The study was carried out over two consecutive years with four different varieties. Glycosidic precursors were analysed in grapes and volatile compounds were studied in the wines. ANOVA studies were performed to study the effect of the vintage, variety and treatment for each of the compounds released from their precursors.


RESULTS
Regarding treatment, the highest values in the concentration of free aroma compounds were achieved in the leaf plucking grapes, except for Chardonnay. Significant and positive correlations between aromatic precursors of terpenes present in grapes and their released form in wines were found for all varieties. For norisoprenoids, significant and positive correlations were exclusively found for Chardonnay and for phenols and vanillins in the year 2010 the correlations were high in three of the four varieties studied.


CONCLUSIONS
In the assays of the 2 years, more precursors were synthesised in Merlot, Gewurztraminer and Tempranillo grapes if the vineyards were plucked.
Laboratory for Flavour Analysis and Enology, Department of Analytical Chemistry, School of Sciences, University of Zaragoza, 50009, Zaragoza, Spain.
Purificacion
P
Hernandez-Orte
Belen
B
Concejero
Jesus
J
Astrain
Blanca
B
Lacau
Juan
J
Cacho
Vicente
V
Ferreira
D000383:Agriculture / Q000379:methods*; D018556:Crops, Agricultural / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D063427:Food Quality; D005638:Fruit / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D006027:Glycosides / Q000032:analysis / Q000096:biosynthesis / Q000737:chemistry; D006801:Humans; D045792:Norisoprenoids / Q000032:analysis / Q000096:biosynthesis / Q000737:chemistry; D009812:Odorants; D018515:Plant Leaves / Q000254:growth & development; D018520:Plant Shoots / Q000254:growth & development; D025341:Principal Component Analysis; D012677:Sensation; D013030:Spain; D013045:Species Specificity; D013729:Terpenes / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D027843:Vitis / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D014835:Volatilization; D014887:Weather; D014920:Wine / Q000032:analysis*
D006027:Glycosides; D045792:Norisoprenoids; D013729:Terpenes; D055549:Volatile Organic Compounds
aromatic precursors; basal leaf plucking; grape; head trimming; wine