Question

which algae produce algin and carrageen​

Answer 1

Red seaweeds contain carrageenan. Because of their water-holding properties, many of these carbohydrates (particularly carrageenan and alginate) are extracted from seaweeds and used to thicken a variety of foods, including soy milk, chocolate milk, ice cream, yogurt, soups, salad dressings and jellies.

Answer 2

I think blue green algae is been produced during this process