Determination of carrageenan by means of photometric titration with Methylene Blue and Toluidine Blue dyes.

A new approach to carrageenan quantitation was described. The method consists in titration of carrageenan solution by Methylene Blue dye or Toluidine Blue dye solution until a certain absorbance value. The optimal wavelengths are 660nm and 640nm when titrating with Methylene Blue dye and Toluidine Blue dye, respectively.