Soluble protein extracts of melons (Cucumis melo) with superoxide dismutase activity >30 units/mg protein and, preferably, catalase activity >45 units/mg protein can be used as antioxidants in foods, cosmetics and pharmaceutical preparations. Preferably, these protein extracts should be prepared from melon cultivars obtained by genetic crossing and with a shelf life of 14 days, especially the line 95LS444 or a hybrid derived from this line.