Dielectric barrier discharge plasma improved the fine structure, physicochemical properties and digestibility of α-amylase enzymatic wheat starch

Abstract

Plasma is growingly used in the modification of starch granules as an emerging non-thermal technology. The study was aimed to investigate the improving role that the plasma process plays in the structure, physicochemical and functional properties of enzymatic starch. Therefore, this work modified wheat starch by α-amylase (20, 40 and 60 U/mL), assisted by post-processing plasma technology for different durations (2, 6 and 10 min). When the plasma and α-amylase were applied to wheat starch, respectively, the molecular weight, amylopectin side chains, crystallinity, R1047/1022 value, swelling power and pasting viscosity decreased significantly. In contrast, the gelatinization temperatures, enthalpy and resistant starch (RS) enhanced particularly compared with the native starch. Notably, enzymatic starch assisted by plasma post-treatment exhibited more severe surface damage and lower crystallinity, short-range order, more linear short chains, and higher RS content than single modified starch. Furthermore, the principal components analysis indicated that the physicochemical characteristics of starch were highly connected with the change of the molecular structure. Thus, the α-amylase hydrolysis combined with the plasma process exhibited a remarkable ability to modify starch with new characteristics and can be used to produce food with low digestibility.