Effect of high hydrostatic pressure on modified noncrystalline granular starch of starches with different granular type and amylase content

Waxy corn (A-type pattern, amylopectin with trace amounts of amylase) and tapioca starch (C-type pattern, 17 g/100 g amylase content) were modified by High Hydrostatic Pressure (HHP) to produce noncrystalline granular (NCG) starch, respectively. The changes in the starch structure and properties occurring upon modified NCG after high-pressure treatment (300-600 MPa/30 min) were analyzed using polarized light microscopy (LM), differential scanning calorimetry (DSC), particle size distribution and scanning electronic microscopy (SEM). The resulting modified NCG starch took place when the 50 g/100 g starch suspension was treated under 450 MPa for the waxy corn starch with swelling degree of 57.07%, whereas 600 MPa for the tapioca starch with restricted starch swelling degree of 16.48%, indicating the stabilization effect of amylase. Also, they had reduced gelatinization temperatures, and lower pasting viscosities, which suggested that HHP had an effect on the physicochemical properties of native starch by destabilization, hydration and swelling.

► Waxy corn and tapioca starch were modified by HHP to produce NCG starch. ► HHP modified NCG starch depended on the botanical source and crystal arrangement. ► HHP modified NCG starch depended on pressure and moisture content. ► Modified NCG starch had reduced gelatinization temperatures and pasting viscosities. ► Particle size distribution and granular morphology of NCG starch were analyzed.