Effect of extraction methods on Lyophyllum decastes crude polysaccharides for modifying wheat starch pasting,...

Wheat starch, providing 20 % of global daily energy, faces critical limitations including heat instability and rapid digestibility that restrict utility and elevate metabolic risks. To address this, crude polysaccharides were separately extracted from Lyophyllum decastes(L. decastes) treated by conventional pulverization (LDCP) or steam explosion (LDSP) to modify wheat starch, and their effects on wheat starch properties and digestibility were further investigated. Steam explosion (SE) significantly increased crude polysaccharide yield (9.81 % to 20.09 %), total sugar (36.93 % to 62.96 %) and β-glucan content (17.89 % to 40.73 %). Analyses of starch-crude polysaccharides complexes revealed that L. decastes crude polysaccharides inhibited pasting, reduced amylose leaching (7.27 % for 10 % LDSP and 15.14 % for control), enhanced thermal stability and promoted long-term retrogradation. Consequently, they significantly lowered rapidly digestible starch (RDS) while increasing resistant starch (RS), with 10 % LDSP reducing RDS to 46.79 % lower than LDCP (50.25 %). Mechanistically, polysaccharides formed surface gels that restricted enzyme accessibility, with LDSP generating more stable complexes. These findings highlight SE's potential to optimize functional polysaccharides from L. decastes for modulating starch behavior, offering a basis for their application in low-glycemic or texture-modified food products.