*2.2. Red Seaweeds*

These algae are red because of the pigments phycoerythrin and phycocyanin. The walls are made of carrageenan and cellulose agar. Both of these polysaccharides with a lengthy chain are commonly employed in the industry. Coralline algae, which secrete calcium carbonate on the surface of their cells, are an important category of red algae. *Chondrus*, *Porphyra*, *Pyropia*, and *Palmaria* are some of the most common red algae genera. The antioxidant activity of Phaeophyta (brown seaweeds) is higher than that of green and red algae [25].
