Quality and antioxidant properties of breads enriched with dry onion (Allium cepa L.) skin

► Onion skin contains compounds acting by different mechanisms of antioxidant action. ► Quercetin from dry onion skin was highly bioaccessible during in vitro conditions. ► Quercetin content in breads was, positively correlated with OS addition. ► Antioxidant power of enriched breads was significantly higher than that of a control. ► 3% onion skin addition is a compromise between sensory and antioxidant properties.