A flavor material or flavor derived from a citrus fruit is itself deoxidized, or production thereof is conducted in a deoxidized atmosphere to inhibit oxidation thereof, and the resulting deoxidized flavor material or flavor is added to inhibit oxidation of foods, drinks, aromatic products and medicines, thereby the oxidation of these products is inhibited; namely an oxidation inhibitor and a browning inhibitor comprising the deoxidized flavor material or flavor as an effective ingredient can be provided.