In this work, two-step enzymatic hydrolysis of sweet potato peel was optimized. The effects of time, enzyme dose and temperature on glucose concentration were investigated. The Box-Behnken design was applied and a total of 17 experimental runs were generated for each step. For the liquefaction step, an ANOVA test showed the quadratic model obtained to be significant (p < 0.05). The statistical model predicted the maximum glucose concentration to be 126.66 g/L at a temperature of 56.4 ºC, α-amylase dose 1% (v/v) and time 60 min. A quadratic model was also obtained for the saccharification step and the model was also significant (p < 0.05). The statistical model for the second step predicted the maximum glucose concentration to be 178.39 g/L, established at the temperature of 45 ºC, glucoamylase dose 1% (v/v) and time 60 min. The optimized liquefaction and saccharification conditions were validated with the actual glucose concentrations of 126.03 and 176.89 g/L, respectively.
Hydrolysis; Enzymes; Optimization; Response surface methodology; Sweet potato peel
