Dynamic models for the production of glucose syrups from cassava starch

Abstract

This paper presents two dynamic models for the production of glucose syrups from cassava starch. The models used are based on those proposed by Paolucci et al. [Paolucci, D., Belleville, M.P., Zakhia, N. and Rios G.M., 2000a, Kinetics of cassava starch hydrolysis with Termamyl enzyme, Biotechnol Bioeng, 68(1): 71–77; Paolucci, D., Belleville, M.P., Rios, G.M. and Zakhia, N., 2000b, Kinetics of continuous starch hydrolysis in a membrane reactor, Biochem Eng J, 6(3): 233–238] for the liquefaction stage, and Zanin and Moraes [Zanin, G.M. and Moraes, F.F., 1996, Modelling cassava starch saccharification with amyloglucosidase, Appl Biochem Biotechnol 57–58: 617–625] for the saccharification stage. These models were modified in order to include aspects that were not considered in previously reported studies. Hence, the liquefaction stage can be modeled at different operating temperatures and substrate concentrations; furthermore, this model relates the activity of the enzyme with the temperature. This model of the saccharification stage simulates continuous operation at variable operating temperatures. Additionally, it enables the prediction of reduced glucose production due to the inclusion of a thermal deactivation constant. The improvements to each stage of the models permit a better approximation to real behavior by linking the two models to provide a complete simulation of the process.