Phenolic composition and antioxidant profiles of commercial blueberry cultivars: Implications for selection and quality assessment

Blueberries (Vaccinium corymbosum L.) are a valuable horticultural crop, widely consumed for their high phenolic content and antioxidant capacity. However, significant variability exists among cultivars in their biochemical profiles and defence strategies, which may influence fruit quality and functional value. This study compared 10 commercial blueberry cultivars grown under uniform agronomic conditions in the Maule Region of Chile. We analysed total phenolics, flavonoids, anthocyanins, antioxidant capacity (ferric reducing antioxidant power [FRAP]), and the activity of key antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], peroxidase [POD], and ascorbate peroxidase [APX]), alongside colorimetric parameters Commission Internationale de l'Éclairage L*a*b* color space (CIELab). 'O’Neal' consistently showed the highest levels of non-enzymatic antioxidants and FRAP values, while 'Legacy' and 'Ventura' also displayed strong antioxidant profiles with elevated enzymatic activity. Multivariate analysis revealed two distinct antioxidant strategies among cultivars: one based on enzymatic defences, and the other on phenolic compound accumulation. Strong correlations were found between anthocyanin content and CIELab parameters, suggesting potential for rapid visual screening. These results highlight cultivar-dependent variation in antioxidant systems and support the strategic selection of genotypes with superior nutritional quality and postharvest potential. The findings provide valuable insights for breeding programmes, functional food development, and the expanding blueberry industry.