The effect of microwave power on physicochemical properties of adlay seed starch after high-temperature storage

• The characteristic changes of adlay seed starches stored at high temperature after microwave treatment were investigated. • Microwave treatment promoted the formation of short- and medium-chain starches. • MW-210 was beneficial to enhance the water retention capacity of adlay seeds during high-temperature storage. • The appropriate microwave technology is beneficial to the storage quality of adlay seeds. Adlay is a kind of pseudocereal that is very easy to oxidize and deteriorate during storage. The effects of microwave treatment with different powers (70, 210, 350, 560, and 700 W; 50 s) on the water distribution, microstructure, pasting, rheological, and texture characteristics of adlay seed starch after storage at 37 °C for 30 days were investigated. Compared to MW-0 (only high temperature storage without microwave treatment), microwave treatment was beneficial to reduce the water activity of starch, increase the amylose content, and improve the elasticity and viscosity of starch pastes. In addition, the microstructure and particle size of starch changed, and it was easier to retrogradation after gelatinization. Differences in energy input caused by different microwave powers led to varying degrees of changes in the physicochemical properties of starch. Among them, MW-210 exhibited the lowest water activity (0.25) and the highest bound water content (78.143%), as well as better gel hardness (104.53 N) and chewiness (51.49 mj). This provides theoretical support for improving the adlay seed starch properties and maintaining their edible quality after high-temperature storage.