Esterification of starch with sodium selenite and selenate

Granular potato starch was esterified with selenous and selenic acid sodium salts in the microwave assisted solid state reaction. Degree of esterification (DE) in both cases did not exceed 3.01 × 10−2. Reaction with selenite provided higher DE. DE increased with the applied power of the microwave oven but increased amount of admixed selenium reagents had no positive effect upon DE. The thermal stability of products was higher than that of native starch. The esterification retained granularity of starch but the crystallinity of granules partly ceased as indicated by scanning electron microscopy (SEM) and X-ray diffractometry, respectively.