Optimized Production of Glucose Syrup and Enzyme Membrane Reactor Using in Situ Product Recovery

Batch enzymatic hydrolysis processes require post-treatments to obtain a glucose syrup free of nonhydrolyzed materials and enzymes. An alternative process is the membrane process, which does not require the addition of chemicals. When membrane and enzymatic hydrolysis processes are combined, the resulting process is known as the in situ product recovery (ISPR) process. The present ISPR process studies focus on the efficiencies of enzymatic hydrolysis with continuous feeding of substrate and/or enzymes. However, little attention has been paid to the enzyme immobilization effect, which can be generated using membranes in conjunction with enzymatic hydrolysis during the production process. Temperature and pH affect the efficiency of glucose syrup production during the enzymatic hydrolysis and membrane processes. In this study, a response surface methodology is used to achieve maximum glucose syrup production without a continuous feed of substrate and/or enzymes. This study also focuses on the evaluation of the membranes as an enzyme membrane reactor. The membrane system operates with submerged membranes of hollow fiber in polyvinylidene fluoride with pure wheat starch in discontinuous diafiltration mode. Results indicated that the maximum glucose production is 73.6 ± 4.3 gglucose L-1 at 61.5 °C and pH 4.8. Besides, the fouling layer in the membranes act as a reactor. This reactor contributes to greater stability and resistance to sudden changes in operating variables. The reactor also has the potential to be reused, thus reducing costs associated with new membranes and enzymes.