## Results and Discussion
### Aroma-Active Volatiles of Cultivated Highbush Blueberries
Geraniol, \(\alpha\)-terpineol and linalool contributed strong aromas to the fruit of all five cultivars (Table 3). Linalool was the most abundant monoterpenoid comprising, on average, approximately 9% of the total volatiles, while \(\alpha\)-terpineol comprised approximately 2% of the total volatiles. Geraniol averaged only 0.24% of the total volatiles but was the strongest contributor to aroma, having the first or second highest MF value for all five cultivars. Linalool, \(\alpha\)-terpineol and geraniol were previously reported in highbush blueberries [12; 17; 20; 29; 32; 33]. In four cultivars of Southern highbush fruit, linalool, and to a lesser extent, \(\alpha\)-terpineol, contributed to the aroma of fruit, but geraniol only contributed to the aroma of two of these cultivars [10]. The occurrence of the remaining fifteen monoterpenoids that were identified through GC-O in this study varied among the five cultivars. With the exception of 2,6-dimethyl-2,6-ocadiene, no additional monoterpenoids were identified in 'Jersey' fruit by GC-O. Six of the identified aroma-active monoterpenoids were only found in fruit of one of the five cultivars. Other studies reported differences in monoterpenoid composition among cultivars [14; 19; 33; 34; 35; 36], and it was suggested that differences in monoterpenoid content could be responsible for the distinct aroma of different blueberry cultivars as well as consumer acceptability [14; 36]. Branched-chain esters also contributed \"fruity\" and \"sweet\" aroma to highbush blueberry fruit, but their contribution varied among the five cultivars. Methyl1-methylbutanoate, ethyl 2-methylbutanoate and methyl 2-methylbutanoate were strong contributors to the aroma of 'Jersey' fruit and moderate contributors to 'Brigitta' fruit (Table 3). In 'Aurora' fruit, ethyl 2-methylbutanoate and ethyl 3-methylbutanoate were strong contributors to the aroma. In contrast, the aroma from these esters was not detected in 'Liberty' fruit. The GC-MS volatile profiles of these fruit found methyl 3-methylbutanoate to be the most abundant branched-chain ester, followed by methyl 2-methylbutanoate, and they comprised approximately 12% and 5% of the total volatiles in 'Jersey' and 'Brigitta' fruit, respectively, but \(<\)1% in the other three cultivars (Table 4). Other studies have shown that the contribution of branched-chain esters to highbush blueberry flavor is cultivar dependent. [PERSON] et al. [33] found high levels of branched-chain esters in 'Duke' fruit but low concentrations in 'Aurora' and 'Liberty'. In both Northern and Southern highbush fruit, GC-O analysis identified that all four methylbutanoate contributed \"fruity\" aroma notes, although the contribution of each varied among cultivars [10; 20]. In fruit from six highbush blueberry cultivars, GC-MS analysis detected methyl 2-methylbutanoate and ethyl 3-methylbutanoate in all six cultivars and ethyl 2-methylbutanoate in five of the six cultivars in low or trace concentrations, but methyl 3-methylbutanoate was not detected [29]. [PERSON] et al. [33] suggested that branched-chain esters were associated with highbush cultivars that had desirable flavor. The C\({}_{6}\) alcohols and aldehydes were strong contributors to the aroma of cultivated highbush blueberry and comprised nearly half of the volatile compounds (Tables 3 and 4). (\(E\))-2-Hexenal and hexanal comprised 27.1% and 10.1% of the total volatiles, respectively. However, (\(Z\))-3-hexen-1-ol that comprised only 0.4% of total volatiles was the strongest contributor of aroma to fruit of all five cultivars based on MF values. (\(E\))-2-Hexenal and hexanal, which were also strong aroma contributors, were not identified by GC-O in 'Jersey' fruit. Moreover, GC-O analysis did not detect (\(E\))-2-hexen-1-ol in 'Liberty' fruit or (\(Z\))-3-hexenal in 'Brigitta' fruit. In two cultivars of Northern highbush fruit, GC-O identified all six of these C\({}_{6}\) aldehydes and alcohols but only (\(Z\))-3-hexen-1-al and (\(Z\))-3-hexen-1-ol made a strong contribution to aroma [20].