Effects of Polysaccharides from Highland Barley on Gelatinization and Rheological Properties of Corn Starch

Abstract:

To study the effects of β-glucan(HBBG) and arabinoxylan(HBAX) extracted from highland barley on the gelatinization and rheological properties of corn starch(CS), highland barley-derived polysaccharides with a series of concentrations were mixed into CS solution. The viscosity properties and morphological features of different mixtures were studied by rapid-visco analyzer (RVA), rheometer and scanning electron microscope (SEM). The results indicated that both HBBG and HBAX reduced the breakdown value, increased the gelatinization peak time, and finally improved the thermal stability of CS gel. HBBG with linear chain structure increased the apparent viscosity, storage modulus (G′), and loss modulus (G″), thus enhancing the viscoelasticity of CS gel by cross-linking with starch and self-aggregation. However, HBAX with highly branched structure reduced the amount of leached amylose, peak viscosity, consistency coefficient (K), G′ and G″, consequently increasing the fluidity of CS system by covering around the starch granules to inhibit the swelling of starch.