A systematic study of green wheat kernel starch: Multi-scale structure, physicochemical properties, polyphenol binding and Pickering emulsifying capacities

This study explored the structural and physicochemical properties of green wheat kernel starch (GWKS) and their effect on Pickering emulsion performance with polyphenol complexes. Compared to mature wheat starch (WS), GWKS had lower amylose content (28.20 ± 0.27%), greater branching (4.91%), and longer amylopectin chains, resulting in more double-helix structures but lower crystallinity. These traits gave GWKS better swelling power and thermal stability but weaker gel strength and slower retrogradation. For polyphenol-starch complexes, tannic acid (TA) bound strongly to GWKS, improving interfacial wettability (contact angle ∼90°), while gallic acid (GA) and epigallocatechin gallate (EGCG) failed to stabilize GWKS-based emulsions. GWKS-TA emulsion showed superior stability, with fine droplets (D 50  = 24.19 μm) and a strong elastic gel network, outperforming WS-based emulsions. The structural predominance of the branched-chain network in immature starch governs its intrinsic properties and underpins the enhanced stability of GWKS-TA emulsions, offering new pathways for advanced processing and high-value applications.