A kinetic assessment of the enzymatic hydrolysis of potato (Solanum tuberosum)

The biotechnology industry demands raw materials to prepare growth media for fermentative processes. These media contain a carbon source which can be obtained from potato, an abundant source of starch. This work deals with the modelling of the enzymatic hydrolysis of potato using α -amylase and glucoamylase. Several strategies were evaluated, including the use of those enzymes alone, in a mixture and under different conditions of temperature, time and substrate concentration. Using α -amylase alone or glucoamylase alone, both enzymes reached the same hydrolysis yield (0.42 g/g). The hydrolysis using a mixture of both enzymes allowed obtaining hydrolysates with reducing sugar concentrations up to 14.1 g/L at 70 °C. In this case, the yield of hydrolysis was increased up to 0.82 g/g. Considering the important effect and interactions of time and temperature, a statistical Box–Behnken design was conducted including substrate concentration, time and temperature as operational variables and reducing sugar concentration released as dependent variable. The conditions to obtain the maximum response were 6% DM of substrate concentration, 68 °C and 180 min, where 32.62 g/L of reducing sugar concentration was predicted. Verification experiments gave a mean value of 33.57 g/L, confirming the accuracy of the model.