The effects of E-beam irradiation and microwave combination treatment on the morphology, structure and physicochemical properties of red adzuki bean starch

This study investigated the effects of microwave (MW, 300W, 900W), electron beam irradiation (EBI, 8, 24 KGy), and their combination (MW-EBI, EBI-MW) on the morphology, structure and physicochemical properties of red adzuki bean starch. MW or EBI treatments had little effect on starch morphology, but high-frequency MW and high doses of EBI combined modification resulted in starch granule cracking. Both EBI and MW treatments retained the C-type crystalline structure of the starch but reduced the relative crystallinity, Mw, and short-range ordering. Besides, starch's short chain (A, B1) content, pasting temperature, solubility, and RDS content were significantly increased. In contrast, long chain (B2, B3), SDS + RS content, ΔH, SP, and RDS content were decreased considerably after MW and EBI treatments. Furthermore, the effect of MW and EBI combined modification on starch was higher than the single modification, and the MW-EBI modification was more effective than EBI-MW. Therefore, this study provides a green and efficient method to modify starch, which helps to broaden the scope of starch application.