Comparative investigation of the effects of electron beam and X-ray irradiation on potato starch: Structure and functional properties

Electron beam (particle radiation) and X-ray (electromagnetic radiation) without radioisotope in the application of material modification have received increasing attention in the last decade. To clarify the effect of electron beam and X-ray on the morphology, crystalline structure and functional properties of starch, potato starch was irradiated using electron beam and X-ray at 2, 5, 10, 20 and 30 kGy, respectively. Electron beam and X-ray treatment increased the amylose content of starch. The surface morphology of starch did not change at lower doses (< 5 kGy), but starch granules were aggregated with the increase of doses. All treatments decreased crystallinity, viscosity and swelling power but increased solubility and stability properties. The effects of electron beam and X-ray on the starch had a similar trend. Unlike X-ray, electron beam destructed the crystallinity of starch to a lesser extent, thereby increasing thermal stability and freeze-thaw stability. Furthermore, X-ray irradiation at higher doses (> 10 kGy) resulted in outstanding anti-retrogradation properties of starch compared with electron beam treatment. Thus, particle and electromagnetic irradiation displayed an excellent ability to modify starch with respective specific characteristics, which expands the potential application of these irradiations in the starch industry.