Characterization of blueberry fruit powders as functional food ingredients rich in polyphenolic compounds

This study aimed to obtain freeze-dried highly bioactive powders from 10 blueberry fruit cultivars, which were analysed for their physicochemical and health-promoting properties. Twenty-four phenolic compounds (12.1 to 70.9 mg/g) were identified in the obtained powders, where anthocyanins were the predominant group, including malvidin 3-O-glucoside in the highest concentration. The richest phenolic profile was shown for the powder from the ’Star’ fruit variety, which also had the strongest OH• (107.89 μg/ml) and O2• (65.16 μg/ml) radical scavenging potential, as well as the highest anti-diabetic (1.87 mg/ml) and anti-obesity (1.24 mg/ml) effects. For ’Star’ fruit powders, the highest antiproliferative activity was also demonstrated, including the strongest against colon cancer cells (Dld-1, 116.52 μg/ml), while showing lower activity against normal colon epithelial cells (CCD841CoN). Furthermore, the proven properties were strongly dependent on the anthocyanin content. Overall, extraction to the solid phase in combination with freeze-drying influenced the quality of the powders, leading to improved functional properties.