Factors impeding enzymatic wheat gluten hydrolysis at high solid concentrations. Issue 7 (20th February 2014)

• Record Type: Journal Article
• Authors: Hardt, N.A.; Janssen, A.E.M.; Boom, R.M.; van der Goot, A.J.
• Is Part Of: Biotechnology and bioengineering. Volume 111:Issue 7(2014:Jul.)
• Page Start: 1304
• Page End: 1312
• Publication Date: 2014-02-20
• Subjects: Biotechnology -- Periodicals; Bioengineering -- Periodicals; 660.6
• DOI: 10.1002/bit.25197
• Languages: English
• ISSNs: 0006-3592

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>ABSTRACT</title> <sec id="bit25197-sec-0001" sec-type="section"> <p>Enzymatic wheat gluten hydrolysis at high solid concentrations is advantageous from an environmental and economic point of view. However, increased wheat gluten concentrations result in a concentration effect with a decreased hydrolysis rate at constant enzyme‐to‐substrate ratios and a decreased maximum attainable degree of hydrolysis (DH%). We here identified the underlying factors causing the concentration effect. Wheat gluten was hydrolyzed at solid concentrations from 4.4% to 70%. The decreased hydrolysis rate was present at all solid concentrations and at any time of the reaction. Mass transfer limitations, enzyme inhibition and water activity were shown to not cause this hydrolysis rate limitation up to 50% solids. However, the hydrolysis rate limitation can be, at least partly, explained by a second‐order enzyme inactivation process. Furthermore, mass transfer impeded the hydrolysis above 60% solids. Addition of enzyme after 24 h at high solid concentrations scarcely increased the DH%, suggesting that the maximum attainable DH% decreases at high solid concentrations. Reduced enzyme activities caused by low water activities can explain this DH% limitation. Finally, a possible influence of the plastein reaction on the DH% limitation is discussed. Biotechnol. Bioeng. 2014;111: 1304–1312. © 2014 Wiley Periodicals, Inc.</p> </sec> </abstract>