Spice Up Your Life: Analysis of Key Aroma Compounds in Shiraz

Fortification and Elevated Alcohol Concentration Affect the Concentration of Rotundone and Volatiles in Vitis vinifera cv. Shiraz Wine

“…No obvious rotundone increase was observed in the Ts-day5 treatment, likely due to the less rotundone extraction time after wine alcohol reaches a relatively high level. Rotundone, similar to other sesquiterpenes, exists in the exocap of the grape berry (skin), rather than the mesocarp (flesh) [5,14,20]. Therefore, longer contact time between grape exocap and the fermented juice is critical for rotundone extraction.…”

“…Rotundone extraction during primary wine fermentation at different alcoholic strengths was further investigated under commercial winemaking conditions (Figure 2). Previous studies reported that rotundone extraction was concentrated during the 2nd to 5th day of fermentation [5,20]; however, rotundone was continuously extracted until pressing (7th day of fermentation). Increasing rotundone concentration by alcoholic strength of wine was observed for the Tc-h (y = 4.42e 0.1212x , R 2 = 0.9627, RSME = 1.486), Tc-berry (y = 5.966e 0.0773x , R 2 = 0.882, RSME = 1.837) and Tc-bunch treatments (y = 9.007e 0.07415x , R 2 = 0.9351, RSME = 1.183).…”

“…Some of these compounds, in particular monoterpenes, are hydrolysed from an odourless glycosidic form into active aromatic form during winemaking and/or storage [2]. Rotundone, an oxygenated bicyclic sesquiterpene in grape berries, is unlikely to undergo modification during fermentation, and remains chemically unchanged from the grape to the wine [3][4][5]. Rotundone is responsible for the attractive "pepper" character in grape berries and wine, and is especially important for cool-climate Shiraz (Syrah) [6][7][8].…”

“…Rotundone mainly accumulates in the first five days of primary fermentation in Shiraz [5,20]. Caputi et al [21] reported the low extraction rate of rotundone during the fermentation process of Vespolina grapes (less than 10% recovered in wine).…”

Effect of ripeness and viticultural techniques on the rotundone concentration in red wine made fromVitis vinifera L. cv. Duras

“…Specific anosmia to this compound has been reported, for example approximately 20% of panellists could not detect this compound during the first sensory trials at the highest concentration tested (4000 ng/L), even in water ). Since then, rotundone has been identified in an increasing number of vine cultivars, including Grüner Veltliner, Vespolina and Schioppettino , and Durif and Graciano (Herderich et al 2012). A high concentration of rotundone was recently recorded by the Institut Français de la Vigne et du Vin in French grape cultivars, such as Pineau d'Aunis (up to 200 ng/L) and Gamay (up to 88 ng/L) grown in cool climate vineyards (Olivier Geffroy, unpubl.…”