Four antioxidant treatments (none, 0.05% ascorbic acid, 0.01% α-tocopherol+0.01% sesamol, and 0.05% ascorbic acid+0.01% α-tocopherol+0.01% sesamol) were applied to ground beef using either mixing or spraying method. The meat samples were placed on Styrofoam trays, irradiated at 0 or 2.5 kGy, and then stored for 7 d at 4° C. Color, lipid oxidation, and volatiles were determined at 0, 3, and 7 d of storage. Irradiation increased lipid oxidation of ground beef with control and ascorbic acid treatments after 3 days of storage. α-Tocopherol+sesamol and ascorbic acid+α- tocopherol+sesamol treatments were effective in slowing down lipid oxidation in ground beef during storage regardless of application methods, but mixing was better than spraying method. Ascorbic acid was the most effective in maintaining redness of ground beef followed by ascorbic acid+α-tocopherol+sesamol. Beef sprayed with antioxidants produced more hydrocarbons and alcohols than mixing application, but ascorbic acid+α-tocopherol+sesamol treatment was effective in reducing the amount of volatiles produced by irradiation. Therefore, mixing was better than spraying method in preventing lipid oxidation and maintaining color of irradiated ground beef.