Effects of microwave treatment on the physicochemical properties, structure, and
in vitro
digestibility of sweet potato starch–lipid complexes with
Renbing Qin, Mengmeng Zhou, Jiaming Zhu, Jinfeng Hua, Ruiqiang Luo, Haiyan Gao, Jie Zeng, Fengjuan Xiang Abstract
BACKGROUND
Sweet potato starch (SPS) is an abundant and cost‐effective agricultural resource with broad application prospects, but its poor thermal stability and high digestibility restrict industrial utilization. The formation of starch–lipid complexes is a green physical modification method to improve starch functionality, and microwave irradiation with rapid volumetric heating is an efficient alternative to conventional hydrothermal processing. However, the chain‐length‐dependent mechanism by which microwave treatment regulates the structure and digestive properties of SPS–fatty acid (FA) complexes remains unclear, hindering the rational design of low‐glycemic ingredients.
RESULTS
Longer chain FAs formed complexes with higher thermal stability and resistant starch (RS) content. Microwave treatment reduced complex quantity but enhanced structural order and crystallinity, forming more perfect V‐type crystals. This structural refinement reduced digestibility significantly, with the microwave‐treated stearic acid complex (SA–M) showing the highest RS content (46.8%) and lowest estimated glycemic index (eGI) (68.3).
CONCLUSION
Microwave treatment acts as a chain‐length‐dependent structural refinement process, optimizing starch–lipid complexes towards more ordered and digestion‐resistant forms, providing a strategy for developing low‐glycemic‐index starchy foods. © 2026 Society of Chemical Industry.