Abstract: Carboxymethyl chitosan (N,O-CMC) was prepared by reacting chitosan with chloroacetic acid and various degrees of substitution (DS) were obtained. These N, O-CMC were added into blackberry juice and the results indicated that it could clarify the blackberry juice. The clarification of juice increased with DS values and reached maximum at a DS value of 0.86, and then decreased. The components of clarified juice indicated that CM-chitosan could reduce the contents of proteins, polyphenols and total sugars in blackberry juice.

Key words: carboxymethyl chitosan, degrees of substitution, blackberry, clarification