EVOLUTION OF CHEMICAL AND SENSORIAL PROFILE OF WINES ELABORATED WITH THEIR OWN TOASTED VINE-SHOOTS AND MICRO-OXYGENATION

Abstract

The positive contribution of toasted vine-shoots (SEGs, Shoot from vines – Enological – Granule) used in winemaking to the chemical and sensory profile of wines has been widely proven. However, the combination of this new enological tool with other winemaking technologies, such as micro-oxygenation (MOX), has not been studied so far. It is known that micro-oxygenation is used in wineries to stabilizes color, improves structure or combining with oak alternatives products to achieve a more effective aroma integration of wines. For that, its implementation in combination with SEGs could result in differen-tiated wines.

In this work, Tempranillo wines were in contact with their own SEGs in two different doses (D1 and D2), added at the end of malolactic fermentation and with two fixes dosages of micro-oxygenation (low, LMOX; and high, HMOX). At the end of the SEGs-MOX treatments, wines were bottled, and a sensory analysis was carried out over 6 months using a specific scorecard which included color, olfactory and taste descriptors. Also, along with the traditional olfactory and taste descriptors, a new one, named SEGs, was included to describe the specific impact of the vine-shoots. Besides, the phenolic and volatile compositions of wines were analyzed by HPLC-DAD and SBSE-GC/MS, respectively.

In the visual phase, the most significant factor was the time in bottle, being wines more violet at bottling and redder after 6 months. About the olfactory phase, the response was different depending on the SEGs dose, being wine elaborated with the highest doses of SEGs and MOX which showed the highest notes of toast, red fruits and nuts, and a very significant reduction of the herbaceous notes. This sensory profile was also maintained after bottle ageing, although the floral notes were slightly reduced, and the red and nuts notes increased. In the taste phase, panelists described wine elaborated with the highest micro-oxygenation dose (HMOX) and after 6 months in bottle with the most pronounced notes of SEGs, nuts and toast, independently of the SEGs dose used. On his part, tannins became less silky in all wines with time in bottle, regardless of the dose of SEGs and MOX used. Regarding the volatile compounds, bottle time was the most important factor for the differentiation, being wines from 3 months in bottle those that showed higher levels of aldehydes and norisoprenoids and, after 6 months, the concentration of alcohols, volatile phenols and esters was increased. As for phenolic compounds, a general decrease in the total content was observed with bottling, being trans-resveratrol the compound that remained practically constant.