Glucan to AR-12 conversion (CG, glucose/potential glucose, in percentage) is defined as the ratio between glucose generated in the enzymatic hydrolysis and potential glucose (that corresponds to the total conversion of glucan into glucose without degradation). Xylan to xylose conversion (CX, xylose/potential xylose, in percentage) can be defined in a similar way.
Conversion variation with time in an enzymatic hydrolysis has been modeled using a simple empirical model (Holtzapple et al., 1984) which parameters help to study the process:equation(2)CG=CGMAX·tt+t1/2Gequation(3)CX=CXMAX·tt+t1/2Xwhere CGMAX (%) and CXMAX (%) are the glucose and xylose conversions, respectively, at an infinite reaction time, and t1/2G (h) and t1/2X (h) are the time needed to achieve 50% of CGMAX or CXMAX, respectively. The first set of parameters (CGMAX, CXMAX) measures the maximum possible enzymatic conversion with these operational conditions and the set of parameters (t1/2G, t1/2X) measures the kinetic of the hydrolysis. Both types of parameters have special interest in this study.