Airflow impact milling as a rapid reagent-free strategy for multiscale structural engineering of cassava starch

Cassava starch is widely used in foods, but its poor cold-water solubility and sticky gels limit its applications, requiring modification. Airflow impact milling uses high-velocity airflow and repeated particle collisions to modify starch within seconds, in continuously operating industrial equipment without added water or reagents. Its ability to tailor the multiscale structure and functionality of cassava starch was therefore investigated. Single and double milling reduced the median granule diameter from 20.75 to 13.26 μm and caused progressive granule fragmentation and surface damage, although birefringence remained detectable. Relative crystallinity decreased by 9.0% while the A-type pattern was retained. Gelatinisation enthalpy fell from 12.96 to 10.28 J g-1. After double milling, cold-water solubility, water absorption and oil absorption increased by 30.47%, 10.33% and 77.72%, while peak, breakdown, final and setback viscosities decreased. Single milling may suit sauces and fillings requiring moderate thickening, and double milling instant or cold-prepared foods, beverages and oil-retaining formulations.