The effects of carrageenan on stability of arachin and the interactions between them

The influence of k-carrageenan on the stability of arachin was analyzed. K-carrageenan could significantly enhance the stability of arachin solution. 0.04% k-carrageenan was the most effective when the concentration of arachin was 2.0%. The pH value, ionic strength and temperature significantly affected the stability of mixture system. The system showed good stability at pH 7.0. High temperature was not beneficial for the system. Na+ and Ca2+, especially Ca2+, could induce phase separation of the system at low concentration. The interactions between arachin and k-carrageenan were studied using fluorescence spectroscopy, DSC, SEM and SDS-PAGE analyses. The results revealed that k-carrageenan could adsorb to the surface of arachin. The adsorption may modify the tertiary structure of arachin and the polarity of microenvironment decreased. The complex showed a comparatively homogeneous network structure from SEM analysis. In addition, the thermal stability of arachin was also enhanced by addition of k-carrageenan. Td and ΔH increased significantly, whereas a significant decrease was determined in ΔTd.