2.10. Determination of solubility
The solubility of the dried carrageenan was determined using
the spectrophotometric method of Soedjak (1994). Powders were
suspended in water (40 mg cm3
), heated in boiling water for
3 min, and then centrifuged. The content of soluble carrageenan in
the obtained supernatant was determined by a colorimetric
method using methylene blue (0.41 mM solution) at l ¼ 559 nm.
The results were expressed as the ratio of soluble carrageenan to
the soluble carrageenan in the non-dried raw material.