Development and characterization of Agriophyllum squarrosum starch nanoparticles for enhanced pickering...

Starch nanoparticles exhibit versatile functions across various applications owing to their small size, large specific surface area and high hydrophilicity. In this study, we present a novel approach for preparing Agriophyllum squarrosum (A. squarrosum) starch nanoparticles using microwave dry heating combined with acidification pretreatment. With increased acid concentration and microwave treatment time, the resulting starch nanoparticles showed significant reductions in molecular weight (from 1472.3 kDa to 27.5 kDa), with average diameters as small as 112 nm, indicating extensive breakdown of both α-1,4- and α-1,6-glycosidic linkages. The reduced degree of crystallinity and increased degree of amorphous structure confirmed the results of the molecular analysis. Pickering emulsions stabilized by starch nanoparticles demonstrated increased stability, as evidenced by significantly greater creaming index values (0.85-0.91, p < 0.05) and reduced oil phase separation than those of the control after 7 days of storage. This approach offers a rapid and eco-friendly strategy for producing high-performance starch-based Pickering emulsifiers from underutilized plant sources.