An X-ray study of hydrothermally treated potato starch

摘要: Abstract Potato starch was annealed at temperatures from 44 to 51 °C (66% moisture) and heat moisture treated (HMT) 90–130 °C (at 17–26% moisture). The structural effects of the various hydrothermal treatments were examined with differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) small-angle scattering (SAXS). Annealing HMT both increased DSC gelatinisation temperatures. former narrowed temperature range, while latter broadened it. Gelatinisation enthalpies WAXD crystallinities unaffected by annealing treatments, they decreased 90–120 °C. Furthermore, triggered a gradual transition B- A-type crystallinity when treatment increased. In contrast B-type crystallinity, is reduced post-HMT evacuation accumulated steam. clearly prevented growth or perfection nuclei/crystallites formed during elevated Compared native starch, samples showed more intense 9 nm maximum. This suggested efficient packing crystallites in dense lamellae. HMT, on other hand, resulted development diffuse SAXS background, which became prominent for higher temperatures, eventually replaced stacked lamellae, present starches, are thus disrupted process.