Vaccinium has a mostly circumpolar distribution, with species mainly present in North America, Europe, and Asia. Other wild Vaccinium shrubs, such as the predominantly European V. myrtillus and other bilberries, also produce commonly eaten blue berries. Hybrids of V. corymbosum with other Vaccinium species adapted to southern U.S. climates are known collectively as southern highbush blueberries. Rabbiteye blueberries (V. ashei / V. virgatum) differ from both highbush and lowbush types. Wild lowbush blueberries are smaller than cultivated highbush ones and have intense color. The highbush varieties are darrowii and corymbosum. Vaccinium corymbosum L. is an accepted species in the family Ericaceae, order Ericales. In many languages, bilberries have a name that translates as blueberry in English.
Cultivation and Production
Many commercially available blueberry species are from North America, particularly Atlantic Canada and the northeastern United States for wild (lowbush) blueberries, and several US states and British Columbia for cultivated (highbush) blueberries. North American native species of blueberries are grown commercially in the Southern Hemisphere in Australia, New Zealand and South American nations. Vaccinium meridionale, the Andean blueberry, is wild-harvested and commonly available locally. Canadian production of wild and cultivated blueberries in 2024 was 165,608 tonnes, the country's second-largest fruit crop after apples. In 2024, world production of blueberries, lowbush and highbush combined, was 1.4 million tonnes, led by the United States with 29% of the total, Peru with 25% and Canada with 12%. Chile produced 97,219 tonnes, Mexico 80,534 tonnes and Spain 60,950 tonnes. Quebec produced 43,997 tonnes of wild blueberries, 47% of the total Canadian production. In Maine, lowbush and highbush blueberries together account for 10% of all blueberries grown in North America; some 44,000 hectares are farmed, but only half of this area is harvested each year because pruning practices vary.
Phytochemistry of the Fruit
Blueberries contain anthocyanins, other polyphenols and various phytochemicals that are under preliminary research for their potential biological effects.
Aroma Composition of the Fruit
Monoterpenoids comprised, on average, over 25% of the total volatile content of fruit from five highbush cultivars. Linalool was the most abundant monoterpenoid, at approximately 9% of the total volatiles, while α-terpineol comprised approximately 2%. Geraniol, α-terpineol and linalool contributed strong aromas to the fruit of all five cultivars. The C6 alcohols and aldehydes were strong contributors to the aroma of cultivated highbush blueberry and comprised nearly half of the volatile compounds. (E)-2-Hexenal and hexanal comprised 27.1% and 10.1% of the total volatiles, respectively. Other alcohols and aldehydes with strong or moderate aromas in all five cultivars included 2-ethyl-1-hexanol, which contributed floral and sweet aromas, and 2,6-nonadienal, which contributed green-grassy and floral aromas. The most aroma-active ketone present in all five highbush cultivars was 1-octen-3-one, which on average accounted for only 0.06% of total volatiles. The ketones (E,Z)-2-undecanone, 2-nonanone, 2-heptanone and, to a lesser degree, 1-penten-3-one, added floral and fruity notes to the highbush fruit.
In both Northern and Southern highbush fruit, GC-O analysis identified that all four methylbutanoates contributed fruity notes, although the contribution of each varied among cultivars. In fruit from six highbush cultivars, ethyl 2-methylbutanoate was detected in five of the six cultivars in low or trace concentrations. Branched-chain esters have been suggested to be associated with highbush cultivars that had desirable flavor. The most aroma-active compounds in lowbush fruit were ethyl 2-methylbutanoate, methyl 2-methylbutanoate, methyl 3-methylbutanoate, ethyl 3-methylbutanoate and ethyl propanoate. In highbush fruit they were geraniol, (Z)-3-hexen-1-ol, 1-octen-3-one, α-terpineol and linalool. 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.
Aroma-Active Compounds
Ethyl 2-methylbutanoate, one of the aroma-active compounds of blueberry fruit, has the formula C₇H₁₄O₂. In six highbush cultivars, methyl 2-methylbutanoate and ethyl 3-methylbutanoate were detected in all six, while methyl 3-methylbutanoate was not detected. The aroma volatile composition was more consistent among lowbush fruit samples than among the five highbush cultivars. Many of the aroma-active compounds of wild lowbush fruit also contribute to the aroma of highbush fruit. Those found only in the lowbush fruit of the study were the esters ethyl propanoate, ethyl 2-methylpropanoate and methyl 3-methyl-2-butenoate, the alcohol 1-hexanol and the ketone 3-heptanone.
