Comparative Evaluation of Bioactive Compounds, Antioxidant Capacity, and Quality Traits of Raspberry Cultivars

Although raspberries are widely valued for their health-promoting properties, comprehensive comparative studies integrating pomological quality traits, phenolic compounds, and antioxidant capacities across cultivars with distinct fruit colors remain sparse. Sixteen raspberry cultivars, including 12 red-fruited, three yellow-fruited, and one cultivar with black-purple fruits, were evaluated at a single location during one growing season. This study evaluated the physicochemical parameters, bioactive compounds, antioxidant activity, and selected phenolic acids of red-, yellow-, and black-purple-fruited raspberry cultivars grown under the same environmental conditions. Antioxidant capacity was determined using FRAP and DPPH assays. The results revealed highly significant cultivar-dependent variations in dry matter, total soluble solids, titratable acidity, TSS/TA ratio, vitamin C, tannins, total phenolics, flavonoids, anthocyanins, and overall antioxidant performance. The black purplefruited cultivar stood out with exceptionally high levels of total phenolics, flavonoids, anthocyanins, and FRAP activity. Red cultivars exhibited wide phenotypic and biochemical variability, while yellow cultivars displayed minimal anthocyanin accumulation. Correlation analysis highlighted a strong relationship between antioxidant potential (FRAP) and flavonoid content, alongside moderate correlations with anthocyanins and vitamin C. Most targeted phenolic acids were either not detected or occurred at concentrations below the limit of quantification, with only a few quantifiable detections. These findings provide insight into cultivar-dependent variation in raspberry fruit quality and bioactive composition and may support the selection of cultivars for further evaluation according to specific quality traits.