NMR metabolite profiling and antioxidant properties of Spartan, Jewels, Misty and Camelia blueberries

The health-promoting properties of blueberries are widely recognized and mainly attributed to anthocyanins. However, fruit's chemical composition includes also other components and strongly depends on variety and climatic conditions. Here, 1H NMR metabolite profiling and biological activity of four blueberry cultivars (Spartan, Jewels, Misty, Camelia) grown in Central Italy over two years were reported. Untargeted and targeted NMR analyses allowed to quantify sugars, organic acids, amino acids, anthocyanins, lipids, and other compounds. Spectrophotometric assays evaluated total phenolic and flavonoid content, antioxidant activity, and enzyme inhibitory activity towards cholinesterase, α-amylase, α-glucosidase, and tyrosinase. Statistical analysis showed a correlation between chemical composition and biological activity, revealing markers specific to blueberry cultivars (quinic acid, quercitrin, myo-inositol, myrtillin, petunidin-3-O-glucoside). Almost all antioxidant assays were correlated with the chlorogenic acid level. A strong effect of harvesting on chemical composition and biological activities was observed, with Misty cultivar having the highest antioxidant activity.