Chemical Characterization and Bioactive Profile of a Selection of 45 Rapini Populations

The present study evaluated the chemical profiles and bioactivities of 45 rapini (Brassica rapa L.) populations (RA1-RA45) cultivated in Central Greece. Our results suggest that the tested rapini populations differed in their compositional traits, with coefficients of variation (CV) of 11.2% for protein content (21.2–35.1 g/100 g dw), 7.6% for carbohydrate (52.3–66.6 g/100 g dw), and 13.4% for fat content (2.7–5.09 g/100 g dw). Fructose was the most abundant detected compound (2.5–9.7 g/100 g dw) with a CV of 27.3%, while glucose, sucrose and trehalose were also present in descending order. Citric acid was the most important organic acid, which showed a CV of 33.6% (3.0 to 12.8 g/100 g dw), followed by malic, oxalic, and fumaric acid. The prevalent fatty acids were linolenic, palmitic, and α-linolenic acids (up to 11.99%, 14.00%, and 47.10%, respectively). The RA3 population had the highest amounts of α- and γ-tocopherol (7.4 and 1.55 g/100 g dw, respectively), while the antioxidant activity recorded significant variations in the TBARS protocol. Finally, the hydroethanolic extracts of rapini displayed low antimicrobial capacity against most of the bacterial strains and fungi tested. In conclusion, our results highlight the variability in nutritional content and bioactive compounds of the studied rapini germplasm. Populations RA3, RA14, RA31, and RA32 showed promising results for specific compounds, while RA13, RA17, and RA18 had the highest antioxidant capacity. Therefore, the observed genetic variation could be valorized in upcoming breeding schemes aimed at enhancing the phytochemical profile and nutritional value of this underexploited species.