Effect of H2O2 concentration on molecular weight and functional properties of sulfated polysaccharides from red seaweed (Kappaphycus alvarezii)

κ-carrageenan is sulfated polysaccharides (SPs) extracted from red seaweed (Kappaphycus alvarezii). κ-carrageenan is sulfated anionic polymers composed of D-galactose units linked alternately with α-1,4 and β-1,3 linkages. Low molecular weight (LMW) of κ-carrageenan has large applications in pharmaceutical and biomedical function. In this study, κ-carrageenan was degraded by oxidative methods in the presence of hydrogen peroxide (H2O2). The average molecular weight of degraded κ-carrageenan was measured by intrinsic viscosity methods with the Mark Hauwink equation. The aimed of this research was to study the effect of hydrogen peroxide concentration (0.5-1.5% w/v) on the functional properties and the molecular weight of κ-carrageenan. The condition reaction was kept at pH 7 and temperature 45°C. These results showed that the degradation rate of κ-carrageenan was positively related to H2O2 concentration. The extent of degradation of κ-carrageenan was obtained the amount of 56.5% with operation conditions of 1.5% H2O2 concentration for 20 minutes. The functional properties of the molecular weight of κ-carrageenan were characterized by Fourier transform infrared spectroscopy (FT-IR). FT-IR analysis of treated κ-carrageenan showed that the degradation of κ-carrageenan in the presence of H2O2 caused a slight decrease in sulfate content.