Soluble dietary fibres decrease α-glucosidase inhibition of epigallocatechin gallate through affecting polyphenol-enzyme binding interactions

•Three arabinoxylans or polygalacturonic acid reduced α-glucosidase inhibition of EGCG.•Two β-glucans remained α-glucosidase inhibition of EGCG.•Soluble dietary fibres (SDFs) maintained competitive inhibition character of EGCG.•SDF-EGCG-glucosidase tricomplex formed due to EGCG-SDF and EGCG-enzyme bindings.•Tricomplex reduced hydrogen bondings but remained π-stackings in EGCG-enzyme binding.