Nutritional value and antioxidant capacity of organic and conventional vegetables of the genus Allium

There are indications that organically grown plants are safer for health and have higher antioxidant content than conventional ones. Vegetables of the genus Allium L. are a valuable source of health-promoting substances, including compounds with antioxidant properties. The aim of the study was to compare the antioxidant potential and nutritional value of four species of Allium L. vegetables obtained from organic and conventional production: garlic, leek and red and yellow onion. Their proximate and mineral composition were determined, as well as the content of bioactive substances and antioxidant potential. The study showed that the cultivation method significantly influenced the parameters tested. Comparison of organic vegetables with conventional ones in terms of content of dry matter, crude protein and crude fibre revealed no general trend indicating the superiority of one method over the other. However, all organic vegetables analysed were more abundant in minerals (Ca, Mg, Fe, Zn, Cu and Mn) and bioactive compounds. They also exhibited higher antioxidant capacity as measured by the FRAP and DPPH(.) tests. Their consumption (especially organic garlic and leek) may therefore strengthen the body's natural antioxidant defences and is beneficial for health.