It has been demonstrated that both aerobic and anaerobic oxidation of L-ascorbic acid occur in freshly-produced commercial orange juice in aseptically-filled TetraBrik cartons. The aerobic oxidation proceeds during the initial stage of the degradation process at a rate which is dependent on the L-ascorbic acid concentration, dissolved oxygen level and temperature. However, when the oxygen level reaches equilibrium, an anaerobic process follows at a much slower rate.Comparative studies on food additives, such as sodium metabisulphite, sodium tripolyphosphate, D-sorbitol and carboxymethyl cellulose, which may be used for extending the shelf-life of citrus juices, showed sodium metabisulphite to be the most effective. However, use of L-ascorbic acid derivatives is recommended.