Commonly used food antioxidants: a comparative study in dispersed systems

Some commonly used antioxidants, namely BHA, BHT, TBHQ, α-tocopherol and caffeic acid were comparatively studied in phosphatidylcholine liposomes and in o/w emulsions. Trolox was included as reference. Oxidation was monitored at 37 °C by measuring peroxide formation. Low polarity and sometimes the molecular size seem to be the determining factors for an appreciable antioxidant performance. BHA and BHT were the most effective at the low levels of addition used. α-Tocopherol had an intermediate activity. The pro-/antioxidant behaviour of caffeic acid was concentration dependent. TBHQ activity was slightly better than that of caffeic acid and comparable with that of Trolox. The results add to knowledge for structure antioxidant activity relationships in various systems and may also have a practical outcome concerning the optimum levels of use.