Effects of high hydrostatic pressure on β-glucan content, swelling power, starch damage, and pasting properties of high-β-glucan barley flour

Abstract

The effects of high hydrostatic pressure (HHP) on the physicochemical properties of high-β-glucan barley flour were investigated in the present study. Dough samples were made from two types of barley flour with low and high β-glucan content, respectively, and treated with HHP (200–600 MPa) for 10 min. Although the elevation of pasting properties for the samples treated at 600 MPa was reduced to the same extent as that in wheat flour at normal atmospheric pressure, β-glucan content was maintained regardless of the pressure applied. The significant increase in starch damage of the dough samples at 550 and 600 MPa was confirmed by the results of microscopic observation, which revealed that elliptical starch granules were cracked and damaged in samples with low β-glucan at 600 MPa, and in samples with high β-glucan content at 400 MPa or more. X-ray diffraction patterns of the samples treated at 600 MPa indicated the formation of amylose-lipid complexes that were considered to inhibit the elevation of viscosity.