Microwave-assisted alkaline modification of red seaweed galactans

The production of 3,6-anhydrogalactose units from galactose 6-sulfated residues by alkaline treatment is an important reaction undergone by many red seaweed galactans, used commercially to enhance their gelation behavior, and thus their industrial value. A novel technique utilizing microwave irradiation to carry out the alkaline modification of three structurally different galactans is described. The reaction is accelerated several times with respect to that performed with conventional heating. The effect of the sodium hydroxide concentration was investigated, showing a higher rate around a 2 M base concentration.