Antioxidant capacity, chlorophyll, marker pigment, and protein contents of four
diatoms (Helicotheca tamesis, Haslea silbo, Nitzschia navis-varingica, and
Asterionellopsis glacialis) and one cyanobacterium (Spirulina subsalsa) have been
investigated. N. navis-varingica exhibited the highest chlorophyll a, fucoxanthin,
ascorbic acid, and total antioxidant capacity (TAC) among the five species studied.
Cupric-reducing antioxidant capacities of N. navis-varingica and H. silbo were higher
than other species studied. A. glacialis exhibited the highest total superoxide
dismutase (SOD) activity, H. silbo displayed the highest ascorbate peroxidase (APX)
activity, and Spirulina subsalsa had the maximum phenolic and protein contents.
Overall, compared to other studies in the literature, the contents of phenolics were at
a moderate level, and ascorbic acid content, APX activity, and TAC were remarkably
high. These findings emphasize the potential for novel applications of the microalgal
species used in this study in biotechnology including pharmaceutical, cosmeceutical,
food, and feed industries