Generally, blueberries in a fresh form consist of water (84%), carbohydrates (9.7%), proteins (0.6%) and fat (0.4%). The average energetic value of a 100-g serving of fresh blueberries is estimated at 192 kJ. Blueberries are also a good source of dietary fiber that constitutes 3%–3.5% of fruit weight.
Epidemiological studies have shown evidence that the consumption of these fruits is linked to the prevention of chronic non-transmissible diseases, mainly due to the presence of bioactive phytochemical compounds such as phenolic acids, flavonoids and carotenoids.
The total content of polyphenols in blueberries ranges from 48 up to 304 mg/100 g of fresh fruit weight (up to 0.3%) and strictly depends on the cultivar, growing conditions and maturity, and its estimation may vary depending on the analytical procedure used.
Polyphenols present in blueberries include, i.e., flavonoids, procyanidins (monomeric and oligomeric form), flavonols (i.e., kaempferol, quercetin, myricetin) phenolic acids (mainly hydroxycinnamic acids) and derivatives of stilbenes.
Phenolic compounds in the blueberry can be classified into two major groups: non-flavonoids and flavonoids. Flavonoids with a 15-carbon skeleton arranged in a common basic chemical structure, with two aromatic rings linked by a chain of three carbons, form a C6-C3-C6 system.
Non flavonoids, phenolic or simple acids,are characterized by having a benzene ring, a carboxylic acid grouping ,and one or more hydroxyl groups and / or methoxyl in the molecule.
Bioactive blueberry compounds
