PL liposomes with or without crude carotenoid extract or its fractions were subjected to thermal oxidation at 50 °C and the oxidation was monitored by increase in conjugated diene content. α-Tocopherol was used as a positive control. In the case of liposomes without any sample, the conjugated diene content increased rapidly and at the end of 24 h there was a 23.7 ± 6.0-fold increase compared to the level at time zero (Fig. 1A). Compared to control, in the liposomes-containing samples, the increase was marginal, with highest increase being 4.4 ± 1.7-fold in liposome incorporated with fraction F1. Fraction F3 inhibited the oxidation better than the known antioxidant α-tocopherol, as the increase was only 1.4-fold with fraction 3 compared to 2.2-fold with α-tocopherol. Even in the crude extract the increase was only 1.9-fold at the end of 24 h