Tocopherols, phycocyanin and superoxide dismutase from microalgae: As potential food antioxidants

Background and Objective: Microalgae are photosynthetic organisms that are in contact with several reactive oxygen species, and under these conditions microalgae produce a wide variety of antioxidant compounds to protect from highly oxidant growth conditions, these facts can be used to optimize antioxidant production, however, firstly studies of antioxidant production by microalgae should be done. This work was focused to establish differences of antioxidants formation among microalgae species and elucidate some antioxidant properties of phycocyanin. Materials and Methods: Superoxide dismutase activity was performed by using a commercial kit and determined by spectrophotometry. Phycocyanin and carotenoids were quantified by spectrophotometry and tocopherols were analysed by high pressure liquid chromatography with a fluorescence detector. Trolox equivalent antioxidant activity was determined by using 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic) reagent, scavenging and synergic anti-oxidant activities were also ascertained. Results and Conclusion: The microalgae used in this study produces different amounts of superoxide dismutase, carotenoids, α, δ and γ-tocopherols, and phycocyanin. Trolox equivalent antioxidant activity varied according with the amount of antioxidants produced. Phycocyanin scavenge superoxide and hydrogen peroxide radicals work well to produce synergy with α-tocopherol, increasing protection of biomolecules against oxidation. One microalgae specie may be selected to produce one of the antioxidants mentioned above, but more detailed studies on growth phases are required to improve the antioxidant production. Microalgae has the potential to be considered as a natural antioxidants source.