# Influence of Oak Chips and Oak Barrel Ageing on Volatile Profile in Chardonnay Wine of Romania
###### Abstract  
The influence of the addition of oak chips and barrel ageing on basic wine parameters and volatile compounds of Chardonnay wines has been studied. Chardonnay wines were obtained by the traditional wine-making process. Oak chips (4 g/L--non-toasted and light toasted) were added at the final stage of the winemaking process for ageing 1, 2 and 3 months, respectively. Also, the control wine was aged in non-toasted barrels for the same period of time. Following Liquid-liquid extraction-gas chromatography-mass spectrometry analysis, alcohols, esters, fatty acids, lactones, and phenolic compounds were identified and quantified. The light toasted wine was clearly separated by phenolic compounds (vanillin, \(p\)-vinyl guaiacol and acctovanillone). The floral aroma supplied by 2-phenylethanol was slowly increased by ageing with odor activity values (OAV) higher in aged samples than control wine (1.07). The vanilla scent could be easily perceived in all aged samples, mainly for light toasted chip-treated samples with OAV values between 2.30 and 2.37. After 3 months, the volatile compounds of wine from non-toasted medium (chips and barrels) were almost similar from the volatile profile point of view. This could have economic and vinicination management implications since oak barrels are expensive and the wine oak barrel aging is a long process. All wines studied in this research can provide a viable alternative to young varietal wines. Chardonnay wine; chips; barrels; _Quercus roburr_; volatile compounds; light toast 4.0/. +
Footnote †: journal: Applied Sciences  
is one of the flexible varieties which could adapt to different growth regions with varied weather and soil characteristics [3]. Among white wines, Chardonnay lends itself to a wide variety of production styles, which can be tailored to the target market and that make this grape variety unique. Presently, two tendencies exist for Chardonnay aroma profiles: fruity and light styles and flavored and complex styles [3]. These styles are targeted by current market trends and popularity of wines. Chardonnay allows winemakers different stylistic choices compared to other white wine varieties. Wines can be aged in oak (barrel or chips) and stored after bottling for different periods of time, depending on the desired style [4]. Oak (_Quercus_ sp.) wood is used in the manufacture of barrels due to its chemical and physical properties. Among the other tree species used in winemaking, the oak is unique due to the size and shape of the annual circles that give it durability when transformed into barrel staves [5]. The technological processes used in carpentry, such as seasoning and toasting the wood staves, give the final characteristics of the barrels [6]. Maturing wines in oak barrels is a traditional practice used to improve sensory and quality characteristics. Although fermentation and maturation in oak barrels is desirable for many wine centers, this is not always possible due to high costs [7; 8]. However, an alternative of obtaining wines with significant aromas is the use of oak, non-toasted or toasted (different levels) chips that can be added during the fermentation process of the wine or at the end of alcoholic fermentation [7; 9; 10]. Some studies examine the addition of wood chips in wine during or after alcoholic fermentation [7; 10]. Also, the presence of lees during ageing can improve the organoleptic characteristics of some wines [11]. Recently, the use of alternative vessels to oak barrels during winemaking has become increasingly popular, but little is known about their impact on the chemical composition of the resulting wines [12]. The volatile compounds extracted from the wood depend on a number of factors such as the degree of toasting, the contact duration with wine [13; 14], but also on their geographical origin [5; 15]. The addition of oak chips to finished wines and their effect on the chemical composition of the wine and its sensory characteristics has been widely studied [3; 7; 9].