Evaluation of the antioxidant activity of three microalgal species for use as dietary supplements and in the preservation of foods.

The antioxidant activity of the microalgal ethanolic extracts of Porphyridium cruentum, Phaeodactylum tricornutum and Chlorella vulgaris was determined by means of the β-carotene-linoleate model system. The results show that the activity of C. vulgaris extract was higher than those obtained for the other microalgal extracts tested and for the synthetics BHA (butylated hydroxyanisole), and BHT (butylated hydroxytoluene). In addition, the major constituents present in the ethanolic extracts of the three microalgae species were analyzed by means of GC and GC-mass spectrometry. The results showed that the tested microalgae may be an important source of natural antioxidants, as an alternative to higher plants or the production by chemical synthesis.