Structural characteristics of carrageenan gels: various types of counter ions

The gelation mechanism of κ- and ι-carrageenan with various types of monovalent counter ions are considered by means of small-angle X-ray scattering. The extent of chain aggregation was discussed with the cross-sectional radius of gyration estimated from cross-sectional Gunier plots. The gelation of κ-carrageenan found to involve the multiple aggregation of double helices except for Li+ and Na+-type, while ι-carrageenan gel was consisted of just double helices.