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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #256302
Title: Volatile compounds and sensory attributes of wine from cv. Merlot (Vitis vinifera L.) grown under differential levels of water deficit with or without a kaolin-based, foliar reflectant particle film

Author
item OU, CHANGRONG - Oregon State University
item DU, XIAOFEN - Oregon State University
item Shellie, Krista
item ROSS, CAROLYN - Washington State University
item QIAN, MICHAEL - Oregon State University

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2010
Publication Date: 12/22/2010
Citation: Ou, C., Du, X., Shellie, K., Ross, C., Qian, M. 2010. Volatile compounds and sensory attributes of wine from cv. Merlot (Vitis vinifera L.) grown under differential levels of water deficit with or without a kaolin-based, foliar reflectant particle film. Journal of Agricultural and Food Chemistry. 58:12890-112898.

Interpretive Summary: Wine aroma is detected by receptors in the nasal pathway of humans when very small chemical compounds become airborne as they escape from the liquid media. Aroma compounds in wine originate from the grape and the fermentation process. Vine water stress has been shown to alter fruit composition but little is understood about the effect of these changes on wine aroma and sensory attributes. In this study we measured the influence of a foliar, kaolin-based particle film on vines under differing levels of water deficit on grape maturity, wine aroma and sensory attributes over three consecutive seasons for the cultivar Merlot grown in the high desert region of southwestern Idaho. Vines with or without particle film were irrigated to meet 100, 70, or 35% of estimated crop evapotranspiration (ETc) from fruit set through harvest, or 35% ETc from fruit set until veraison and then 70% ETc until harvest. Replicated lots of wine produced from each treatment level were analyzed for volatile composition using a stir bar sorptive extraction (SBSE)-GC-MS technique and for sensory attributes using trained and untrained sensory panels. Particle film had no apparent effect on wine volatile composition and had an interactive effect with irrigation on wine sensory attributes. Vines under greatest water stress with particle film had increased fresh fruit aroma and lower spicy and bitter flavor relative to vines without particle film. When particle film was applied to vines under 35-70% ETc, the wine had less fresh fruit aroma. Irrigation amount influenced wine volatile composition and sensory attributes. Untrained panelists in 2007 and 2008 detected a difference between well-watered and water-stressed wines. Vine water stress severity affected trained sensory panel perception of dried fruit flavor, bitter taste, drying mouthfeel, and canned vegetal aroma.

Technical Abstract: The influences on wine volatile composition and wine sensory attributes from a foliar application of a kaolin-based particle film on vines under differing levels of water deficit were evaluated over three consecutive seasons for the cultivar Merlot grown in the high desert region of southwestern Idaho. Vines with or without particle film were irrigated to meet 100, 70, or 35% of estimated crop evapotranspiration (ETc) from fruit set through harvest, or 35% ETc from fruit set until veraison and then 70% ETc until harvest. Replicated lots of wine produced from each treatment level were analyzed for volatile composition using a stir bar sorptive extraction (SBSE)-GC-MS technique and for sensory attributes using trained and untrained sensory panels. Particle film had no apparent effect on wine volatile composition and had an interactive effect with irrigation on wine sensory attributes. Vines under 35% ETc with particle film had increased fresh fruit aroma and lower spicy and bitter flavor relative to vines under 35% ETc without particle film. When particle film was applied to vines under 35-70% ETc, the wine had less fresh fruit aroma. Irrigation amount influenced wine volatile composition and sensory attributes. Vines under 35 or 35-70% ETc, had 40 and 100% (2007) or 30 and 50% (2008) higher total amount of wine volatile terpene alcohols and norisoprenoids relative to well-watered vines (100% ETc). The amount of citronellol, nerol, geraniol, nerolidol, and ß-damascenone was greater in wine produced from vines under water deficit, while linalool and ß-ionone remained unchanged. Untrained panelists in 2007 and 2008 detected a difference between wines from 100% and 35% ETc vines and between 35% and 35-70% ETc vines. Irrigation regime affected trained sensory panel perception of dried fruit flavor, bitter taste, drying mouthfeel, and canned vegetal aroma.