Changes on grape volatile composition after elicitors and nitrogen compounds foliar applications to 'Garnacha', 'Tempranillo' and 'Graciano' vines

Grape volatile compounds determine the wine quality and typicity. The aim of this work was to study the effects of several foliar applications in 'Garnacha', 'Tempranillo', and 'Graciano' grapevines in order to enhance their grape volatile composition. The field trial involved the application of two nitrogen compounds, urea (Ur) and phenylalanine (Phe), and two elicitors, methyl jasmonate (MeJ) and a yeast extract (YE). The analysis of grape volatile compounds was carried out by HS-SPME-GC-MS. For 'Garnacha', most terpenes, and C13 norisoprenoids increased their grape content by applying Ur and Phe, and especially MeJ. For 'Tempranillo', treatments with Ur and MeJ improved the synthesis of most terpenoids. For 'Graciano', a trend to decrease the terpenoids content in grapes with the treatments was observed; however, Phe application increased C13 norisoprenoids content. In conclusion, foliar application of, Phe or Ur, and an elicitor, MeJ, can be a useful tool to improve grape quality

Optimization of sample preparation method for multi-element analysis of wines by ICP-MS: Application to classify wines according to several factors.

Wines from different grape varieties, geographical zones, soil types, foliar N application, SO2 addition and oak ageing were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). For this purpose, ICP-MS methodology was optimized. The elements which allowed differentiate wines from studied grape varieties were Sr, Ca, Mg and Mn. Geographical zones were classified according to Sr, Ba, Ni, and Cu. Cs and Pb were the main elements to discriminate the wines from the 3 soil types. Wines from several N foliar doses application were classified by Pb, Ni, Mn and Zn. The content of Cs, Mg, Cu and Pb in wines characterized the SO2 addition. Finally, wines storage in barrels were differentiate by Na and Cs concentration. The discriminant functions classify 100% of the wines, with the exception of grape variety (97.0%) and oak ageing (95.8%). Consequently, ICP-MS can be applied to classified wines according to viticultural and oenological factors