Buckwheat starch: structure, functionality and enzyme in vitro susceptibility upon the roasting process

Abstract

Starch of dehulled buckwheat grains with a moisture content of 14.5% before and after thermal treatment (160°C/30 min) was used in this study. The crystal structure of buckwheat starch was of the A-type. The thermal process applied elicited slight changes both in infrared spectra and relative crystallinity on X-ray diffraction patterns. The scanning electron microscopy studies demonstrated polygonal and irregular shape of starch granules. After the thermal treatment, some breakings or conglomerates were noticed on the granules. The roasting process also affected a decrease in the swelling power and solubility. The release of glucose and changes in resistant starch after partial hydrolysis by pancreatic α-amylase and other intestinal enzymes were analysed as well. The scanning electron microscopy visualization indicated significant susceptibility of buckwheat starch at the beginning (0.5 h) and during 6 h in vitro amylolysis.

• Buckwheat grains
• buckwheat starch
• roasting process
• structure
• functional properties
• in-vitro enzyme susceptibility