Chemical Profiling and Antioxidant Potential of Berries from Six Blueberry Genotypes Harvested in the Italian Alps in 2020: A Comparative Biochemical Pilot Study

This pilot study investigates the chemical profiling and antioxidant potential of six blueberry genotypes: three tetraploids from the highbush blueberry species and three hexaploids from the rabbiteye blueberry species. The goal was to characterise the biochemical composition of these genotypes, grown under identical pedoclimatic conditions, and to evaluate the variation in bioactive compounds associated with antioxidant activity. Metabolomic and ionomic analyses were employed to identify and relatively quantify these compounds. Multivariate analyses clustered the genotypes based on phytochemical profiles, pinpointing key genotype-clustering metabolites. Significant variations among genotypes were observed. Ochlockonee and Overtime had the highest anthocyanins, phenols, ascorbates, and antioxidant activity levels. Over thirty metabolites (organic acids, sugars, and flavonoid glycosides) drove the genotype clustering. Although Last Call and Legacy had more metabolites, their antioxidant properties were lower, suggesting that phenolic quality influences antioxidant activity more than quantity. Overtime had the highest phenolic content, followed by Last Call in anthocyanins. Liberty and Legacy showed the lowest anthocyanin and ascorbate levels, while Overtime and Ochlockonee were characterised by an increase in ascorbate content. Rabbiteye blueberries showed higher antioxidant potential than highbush, indicating that antioxidant efficacy depends more on the composition and quality of the bioactive compounds than on their total concentration.