Effects of pullulanase enzymatic hydrolysis on the textural of acorn vermicelli and its influencing mechanism on the quality.

ABSTRACT

The effect of pullulanase enzymatic hydrolysis time on the textural properties of acorn vermicelli was investigated by texture analyzer. And the influencing mechanism was revealed by exploring the physicochemical properties of acorn starch under the optimum enzymatic hydrolysis time by texture analyzer, scanning electron microscopy, X-ray diffraction and brabender viscograph. After acorn starch was hydrolyzed by pullulanase for 14 h, acorn vermicelli had excellent textural properties. In addition, the enzymatic hydrolysis transformed the acorn starch from spherical particles with smooth surface to polygonal particles with rough surface, as well as transformed the crystal structure of acorn starch from C-type to B-type. Compared with native acorn starch, enzyme hydrolyzed acorn starch had higher amylose content, better freeze-thaw stability, lower swelling power and, breakdown viscosity, stronger gel strength and, higher light transmittance. These excellent properties contributed to the exceptional textural properties and quality of acorn vermicelli. The results of this study may provide valuable information on the preparation of acorn vermicelli.