Gelidium spinosum is one type of red seaweed that is beneficial for human health. Gelidium spinosum is one of the raw materials that produce agar. Agar is a complex polysaccharide hydrocolloid composed of repeating disaccharides with units of (1,3)-linked β-D-galactose and (1,4)-linked 3,6 anhydro-α-L-galactose. These polysaccharides cannot be digested in the human intestine directly, so they…