Removing starch granule-associated surface lipids affects structure of heat-moisture treated hull-less barley starch

The effects of starch granule-associated surface lipids removal on hull-less barley starch structure formed by heat-moisture treatment were investigated. Removing surface lipids made the peak at 2 theta of 13 degrees disappear and resulted in higher lamellar peak intensity after harsh treatment and a lower reduction in mass fractal dimension (from 2.49 to 2.43) and radius of gyration (from 24.3 to 24.0) when temperature increased from 100 to 120 degrees C at 20 % moisture. Treatment at 25 % moisture and 120 degrees C decreased relative crystallinity (from 15.73 % to 7.43 %) and Gaussian peak area (from 646.7 to 137.7) of native starch, and decreased relative crystallinity (from 14.24 % to 12.56 %) and Gaussian peak area (from 604.1 to 539.6) for starch without surface lipids. Different trends of change in lamellar thickness, linear crystallinity, peak temperatures, and enthalpy of gelatinization were observed among modified starches with increasing temperature and/or moisture content. These results demonstrate that removing surface lipids changes structure of heat-moisture treated starch.

Automated summary

The study investigated the effects of removing surface lipids on the structure of hull-less barley starch formed by heat-moisture treatment. The removal of surface lipids resulted in the disappearance of the peak at 2 theta of 13 degrees, increased lamellar peak intensity, and smaller reduction in mass fractal dimension and radius of gyration. Different changes were observed in lamellar thickness, linear crystallinity, peak temperatures, and enthalpy of gelatinization among the modified starches with increasing temperature and/or moisture content.