A kinetic model for enzymatic wheat starch saccharification

✍ Scribed by Christina Åkerberg; Guido Zacchi; Nelson Torto; Lo Gorton

• Publisher: Wiley (John Wiley & Sons)
• Year: 2000
• Tongue: English
• Weight: 139 KB
• Volume: 75
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/(sici)1097-4660(200004)75:4<306::aid-jctb218>3.0.co;2-u

✦ Synopsis

A kinetic model describing the enzymatic sacchari®cation of wheat starch by a mixture of a-amylase and amyloglucosidase has been developed. The model describes the in¯uence of pH, glucose inhibition and starch and enzyme concentration. The results of experimental sacchari®cation under different physical conditions, eg pH and temperature, were used to determine the parameters in the model. The dominant enzyme in the mixture was amyloglucosidase and the maximum rate of sacchari®cation due to this enzyme was found to be optimal at pH 5, and increased Five-Fold when the temperature was increased from 30 to 55 °C. Sacchari®cation due to the action of amyloglucosidase was inhibited by the glucose produced and simulation showed that the maximum rate of sacchari®cation decreased by 58% at a starch concentration of 140 g dm À3 compared with a starch concentration much less than 110 g dm À3 where the effect of glucose inhibition was negligible.