Influence of harvest date on volatile and sensory profile of vine leaves infusions from two Portuguese red grape varieties

The main object of the present study was to investigate the volatile composition and sensorial profile of vine leaves infusions prepared from vine leaves collected 30 and 60 days after grape harvest from two Portuguese red grape varieties (Touriga Nacional and Tinta Roriz). Twelve volatile compounds were detected in vine leaves infusions (6-methyl-5-hepten-2-one, 1-undecene, Z-citral, cedrenol, DL-limonene, 2,4-hexadien-2-ol, benzaldehyde, heptane-1,2,4,6-tetraene, cyclohexene 1-methyl-4-(1-methylethyl), 1,6-octadien-3-ol, 3,7-dimethyl, 5,9-undecadien-2-one-6,10-dimethyl-(5E) and α-cedrol). In addition, it was observed that the volatile compounds present in vine leaves infusions were dependent on the harvest time, with significantly major volatile content in vine leaves collected after 30 days of harvesting. Thus, it was more important the harvesting date for the volatile profile of vine leaves infusion than the vine leave grape cultivar. Similar tendency was also obtained for the sensory profile, with significant differences for astringency and aroma intensity attributes of vine leaves infusions according to the harvesting date.