Reducing sugars and glucosamine analysis—At appropriate time intervals, aliquots of the reaction mixture were boiled
for 10 min to terminate the reaction. Unhydrolyzed chitosan was precipitated by adjusting the pH to 9.0 with 0.1 M NaOH,
and the amounts of reducing sugars and glucosamine in the supernatant were determined by Schales’ modified method
[22]and Ride and Drysdale[23]method, respectively, using d-glucosamine as standard