## Results and Discussion
### Comparison of Aroma-Active Compounds in Wild Lowbush and Cultivated Highbush Blueberries  
Many of the aroma-active compounds identified in wild lowbush blueberry fruit were also identified to contribute to the aroma of cultivated highbush fruit. Of the twenty-three aroma peaks found in wild lowbush blueberry fruit, nineteen were found in at least one of the five highbush cultivars assessed in this study. Aroma-active compounds that were unique to wild lowbush fruit in this study included the three esters ethyl propanoate, ethyl 2-methylpropanoate and methyl 3-methyl-2-butenoate; one alcohol 1-hexanol; and one ketone 3-heptanone. Conversely, of the forty-two aroma-active peaks identified in the five highbush cultivars, twenty-three were not found to contribute to the aroma of wild lowbush fruit. These peaks included sixteen monoterpends, five aldehydes, four ketones, two acids, one alcohol and one hydrocarbon. While there were many similarities in the aroma-active compounds in the fruit of these two species, the quantities of these compounds and their contribution to fruit aroma differed considerably. These differences would impact the flavor of blueberry products and should be considered in product formulation. The volatile profile composition of wild lowbush blueberries was dominated by esters with branched-chain and straight-chain esters comprising 31.6% and 15.9% of the total volatiles, respectively (Figure 1, Table 2). The ester content of cultivated highbush blueberries was lower than that of wild lowbush fruit with branched-chain esters and straight-chain esters averaging 2.4% and 1.0% of total volatiles, respectively (Figure 1, Table 4). Aldehydes were the most abundant volatile group in highbush fruit comprising 47.7% of the total volatiles, while in wild lowbush fruit, they were the second most abundant group comprising 28.6% of the total volatiles. The second most abundant group of volatiles in highbush fruit was monoterpenoids comprising 25.8% of total volatiles. In lowbush fruit, monoterpenoids accounted for only 4.4% of the total volatiles. Similar concentrations of alcohols (8.8% vs. 6.7%), ketones (5.9% vs. 9.5%) and hydrocarbons (2.3% vs. 5.8%) were observed in the wild lowbush and cultivated highbush fruit, respectively. Volatile composition among chemical groups in wild lowbush fruit did not differ significantly among provinces except for straight chain esters (\(p\) = 0.016) that comprised only 4.4% of total volatiles in fruit from PE compared to 13.6%, 23.6%, and 19.3% in fruit from NS, NB and QC, respectively (Table 2). Greater differences in the distribution of volatile compounds among chemical groups were seen in cultivated highbush blueberry fruit (Table 4). Aldehyde composition varied significantly among cultivars (\(p\) \(\leq\) 0.001), comprising over half of 'Aurora', 'Brigitta' and 'Liberty' total volatiles, but <43% of total volatiles in 'Duke' and 'Jersey' fruit. Monoterpenoid content ranged from 47.9% in 'Duke' to 9.6% in 'Jersey' (\(p\) < 0.001). [PERSON] et al. [29] also reported the fruit of 'Duke' to have higher concentrations of total terpen than the fruit of other highbush cultivars. In 'Jersey' fruit, branched-chain esters (11.8%) and ketones (14.7%) were more abundant than monoterpenoids (9.6%). The average composition of other fruit volatiles that differed significantly among the five cultivars studied included ketones, branched-chain esters, straight-chain esters and furans. [PERSON] et al. [33] found three selections from the USDA blueberry breeding program that were considered to have \"outstanding\" flavor had higher branch-chain ester content than seven highbush cultivars. To further explore the differences in the volatile chemistry between wild lowbush and cultivated highbush blueberries, principal component analysis was conducted on the volatile chemical groups (Figure 2). Scores 1 and 2 accounted for 75% of the variability.