Effect of High-amylose Maize Starch at Different Heating Temperatures on the Pasting Properties, Gelation Behaviors and Anti-digestibility of Whole Wheat Flour

This study investigates the effects of high-amylose maize starch (HA) on the pasting properties, gelation behavior, and anti-digestibility of whole wheat flour (WWF) under different high-temperature cooking conditions. Composite flours were formulated by incorporating varying ratios of HA into WWF, with the protein content standardized at 13.8% through gluten adjustment. The composite flours were evaluated for farinograph properties and pasting behavior, thermal characteristics, gel hardness, and digestibility following heat treatments at 100 ℃ and 140 ℃. Results demonstrated that the addition of HA increased water absorption and reduced dough development time. Wheat starch (WHE) in WWF could gelatinize and form a gel network at temperatures below 100 ℃, while HA largely retained its granular form. At 140 ℃, HA could be fully gelatinized, with its granular structure completely destroyed. Notably, gel hardness did not show a consistent trend of reduction with increasing HA content. The enthalpy values of amylose-lipid complexes (ALC) in HA and WWF were determined to be 3.2 J/g and 1.9 J/g, respectively. However, no significant changes in enthalpy values were observed in the composite flour after the addition of HA. The RDS content of the composite flour decreased significantly compared to WWF and the sum of SDS and RS content was greater than the theoretically expected value after treatments at 100 ℃ and 140 ℃. Therefore, the addition of HA could enhance the anti-digestibility of the starch of the composite system more effectively than its own anti-digestibility effect.