# Influence of Oak Chips and Oak Barrel Ageing on Volatile Profile in Chardonnay Wine of Romania
## 4 Discussion
### Odor Activity Values  
Among all the compounds present in Table 3, not all of them present an odor activity value OAV >1 (Table 4), which is normally taken as the value required for a compound to be a likely contributor to the specific aroma. The OAVs based on threshold values in a specific matrix (e.g., neutral white wine or 10% \(v\)/\(v\) aqueous ethanol) act merely as a guide when determining the importance of a compound to wine aroma, due to a significant effect of the matrix [3]. The highest OAV was exhibited, among all samples, by ethyl octanoate characterized by pineapple and apple notes, specific for Chardonnay wines [19]. Ethyl hexanoate and N-amyl acetate are fruity aroma contributors with concentrations above their threshold in all samples, mainly in wine samples treated with light-toasted chips. The method of wine ageing using non-toasted wood products, could preserve the floral character of Chardonnay wines. These results were in accordance with those presented previously by [PERSON] et al. [11], on Muscat Ottonel wines. Regarding the fatty acids, the rancid aroma supplied by isovaleric acid could be easily perceived in the non-toasted oak barrel aged sample, due to the low odor threshold of this compound. The spicy and condiment aroma could be highlighted by L1M-L3M samples, where light toast of chips increased the amount of \(p\)-vinyl guaiacol extracted by wine. The compounds that give wines a vanilla and roasted note (vanillin--VPS, \(p\)-vinyl guaiacol--VP1 and acetovanillone--VP3) are related to the light toasted chips in our study. For short periods of maturation, Chardonnay wines can obtain almost the same qualities if aged with non-toasted chips and non-toasted barrel, from the volatile point of view, but with more efficient cost, from the economical point of view. The PLRS analysis shows that wine samples treated with the French non-toasted oak chips aged for 1 or 2 months have similar wine volatile profiles with those from Romanian non-toasted oak barrels. Some differences between non-toasted variants were observed when the wines were aged for 3 months. Chardonnay is not dominated by a distinct varietal compound as in other varieties like Sauvignon blanc or Muscats. The typicity concept for Chardonnay wines needs more comprehension and requires deeper study, because this is a variety that can express itself in a multitude of profiles. Understanding Chardonnay typicity requires multidisciplinary studies that analyze a number of variables responsible for the final product, rather than a one-directional focus [3]. Nevertheless, the use of oak barrel alternatives, in particular, offers an economic means of imprinting the desirable aroma compounds from oak without the time or expenses associated with ageing wine in oak barrels [57].  
It is not easy to distinguish products obtained by aging with chips from those obtained traditionally (barrel aged) from a sensory point of view. The distinction of the two different products is possible through laboratory investigation techniques: analytical methods allow expanding the compositional differences between the two wine products. Among the analytical techniques used, the spectroscopic ones are certainly those that, combined with multivariate statistics techniques, allow to obtain the best results in this field, for commercial purposes and, if necessary, for the control of fraudulent activities [58].