Abstract:

The endosperm slices of Gleditsia sinensis seed were used as raw materials to prepare cationic Gleditsia polysaccharide by microaqueous solid phase method with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride as the etherifying agent. And the effects of preparation conditions, including the sodium hydroxide dosage, etherifying agent dosage, reaction temperature and reaction time on the viscosity and substitution degree of the product were studied by single factor experiment. The optimal reaction conditions were determined as endosperm slices of Gleditsia sinensis seed 500 g, 250 mL 40% NaOH solution, 500 mL 60% 3-chloro-2-hydroxypropyl trimethyl ammonium chloride solution, reaction temperature 60 ℃ and the reaction time of 4 h. The content of water insoluble substance of cationic Gleditsia polysaccharide was 2.81%, the viscosity was 1 196.2 mPa·s (1% water solution at 25 ℃), and the degree of cation substitution was 0.151. Infrared spectrum and nuclear magnetic resonance results showed that the quaternized reaction of Gleditsia sinensis polysaccharide was realized, the viscosity test of cationic Gleditsia polysaccharide also accorded with the pseudoplastic fluid characteristics.

Key words: microaqueous solid phase method, cation, Gleditsia polysaccharide, process