Beta-carotene generates thiobarbituric acid-reactive substances by interaction with nitrogen dioxide in air.

Generation of thiobarbituric acid-reactive substances (TBARS) from methyl linoleate in the exposure of nitrogen dioxide/air was inhibited by beta-carotene in a dose-dependent manner. However, introduction of nitrogen dioxide/air or oxygen into a solution of beta-carotene generated a significant amount of TBARS accompanying loss of its characteristic yellow color. Storing beta-carotene in a solid state at ambient temperatures in air generated a large amount of TBARS accompanying loss of its yellow color. TBARS from beta-carotene may interfere the measurement of TBARS from polyunsaturated fatty acids, and may give undesirable effects on biomaterials.