Effect of alternating magnetic field pretreatment on the molecular structure and physicochemical properties of maize starch

As a green technology for starch modification, magnetic fields have been garnering growing attention. This study was designed to investigate the effects of alternating magnetic fields (AMF) at various intensities (2–10 mT) on the molecular structure and physicochemical properties of maize starch. The results indicated that, in comparison to the untreated starch, the maize starch pretreated with AMF exhibited enhanced surface porosity, more pronounced surface depression, a decrease in amylose (AM) content (9.93 %–29.87 %), and a reduction in average particle size (3.77 %–8.74 %). Moreover, all samples maintained the typical A–type crystal structure, and a certain AMF intensity enhanced the relative crystallinity (RC) (5.59 %–22.86 %) and molecular orderliness of the starch. In addition, the treated starch exhibited higher thermal stability and lower viscosity and oil absorption properties. Comprehensive analysis indicated that the treatment effect was most significant when the magnetic field intensity was 8 mT. These findings highlight the potential of AMF in the development of low-oil, high-stability starch.