Is used to thicken jellies, which are made from fruit or pureed fruit. Vegetarians often use it is a substitute for gelatin, which is an animal protein, Agar- agar is derived from several species of red seaweed, it is available in the form of powder , flakes, bars, or stands. To use it, bring the liquid containing the substance to the boiling point and melt it over low heat. Agar – agar is rich in iron.