Effect of the glass transition temperature on alpha-amylase activity in a starch matrix. (10th February 2017)

• Record Type: Journal Article
• Authors: Chaudhary, Vinita; Panyoyai, Naksit; Small, Darryl M.; Shanks, Robert A.; Kasapis, Stefan
• Is Part Of: Carbohydrate polymers. Volume 157(2017)
• Page Start: 1531
• Page End: 1537
• Publication Date: 2017-02-10
• Subjects: Starch -- Maltodextrin -- α-Amylase -- Glass transition temperature -- Activation energy; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2016.11.028
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Kinetics of hydrolytic activity of α-amylase on condensed carbohydrate matrices were studied. Activation energies of amylolysis were estimated for the glassy matrices of starch and maltodextrin. Glass transition temperature of the carbohydrate matrix arrests the enzymatic activity of α-amylase Abstract: This study optimises a protocol for the estimation of α-amylase activity in a condensed starch matrix in the vicinity of the glass transition region. Enzymatic activity on the vitrified starch system was compared with that of a reference substrate, maltodextrin. The activity was assayed as the rate of release of reducing sugar using a dinitrosalicylic acid procedure. The condensed carbohydrate matrices served the dual purpose of acting as a substrate as well as producing a pronounced effect on the ability to enzymatic hydrolysis. Activation energies were estimated throughout the glass transition region of condensed carbohydrate preparations based on the concept of the spectroscopic shift factor. Results were used to demonstrate a considerable moderation by the mechanical glass transition temperature, beyond the expected linear effect of the temperature dependence, on the reaction rate of starch hydrolysis by α-amylase in comparison with the low-molecular weight chain of maltodextrin.