Seasonal variation of phenolic content and antioxidant capacity in edible biomass of tagasaste

Tagasaste (Chamaecytisus proliferus) is a perennial leguminous fodder shrub naturalized in a range of environments for its valuable traits. This research was aimed at evaluating the seasonal variation of bioactive compounds and antioxidant properties in edible biomass components (i.e. leaves, twigs, flowers, and pods) of tagasaste grown in a Mediterranean environment of Sardinia (Italy). Season influenced the polyphenolic content and antioxidant capacity of leaves and twigs. Total phenolics of leaves ranged from 48 to 112 g gallic acid-equivalent kg-1 dry weight. Antioxidant capacity of leaves peaked in late summer, reaching 44 mmol/100 g dry weight of Trolox equivalent. The levels of total phenolics and flavonoids were highly correlated with antioxidant capacity. The research provides new insights into antioxidant activity of edible biomass components of tagasaste. Results also indicate that this leguminous shrub has remarkable potential for improving animal nutrition and welfare during the most critical forage shortage for rainfed farming systems of Mediterranean climatic areas.