Abstract: The optimal conditions for the hydrolysis of Lisbon yam flour by thermostable α-amylase were investigated by one-factor-at-a-time and orthogonal array design methods in order to maximize total reducing sugar content in hydrolysates. Meanwhile, the hydrolysis process was analyzed kinetically. The best results of the hydrolysis were achieved after 50 min incubation of 40 mg/mL Lisbon yam flour and 0.07 mL/g thermostable α-amylase at 90 ℃ and pH 5.6, and the resulting total reducing sugar content in hydrolysates, Vm and Km were 52.95%, 1.26 mg/(mL ·min) and 80.84 mg/mL, respectively.

Key words: Lisbon yam, reducing sugar, enzymatic reaction, kinetics