Untargeted phytochemical profiling and biological activity of small yellow onion (Allium flavum L.) from different regions of Romania

•Allium flavum was investigated for its nutraceutical profile and bioactive properties.•A. flavum flowers collected from Făget (AFFF) was the best source of polyphenols.•All the tested extracts exhibited α-glucosidase inhibition potential.•Carotenoids and sulfur compounds correlated with lipase inhibitory activity.•AFFF extracts strongly inhibited radical-induced membrane damage in erythrocytes.