Effects of phosphorylation-modified long-chain inulin on wheat starch: Physicochemical properties and retrogradation behaviors

In this research, modification of long-chain inulin (FXL) through phosphorylation (PFXL) to enhance its application in wheat starch (WS) and starch-based products. The impacts of PFXL on the pasting, rheology, microstructure, and retrogradation characteristics of WS were researched. The findings revealed that PFXL significantly reduced both the breakdown and setback values of WS. Additionally, the incorporation of PFXL reduced the viscoelasticity of WS paste and improved its fluidity. Scanning electron microscopy indicated that higher PFXL levels (>5 %) produced small fragments that partially covered the three-dimensional honeycomb structure of WS paste, thereby reducing water loss during short-term storage. PFXL also altered water distribution in WS gels, depending on concentration and storage duration. X-ray diffraction and Fourier-transform infrared spectroscopy suggested that PFXL effectively inhibited amylopectin recrystallization. Compared to FXL, PFXL exhibited a more pronounced ability to inhibit the aging of WS in short- and long-term storage. •Phosphorylated long-chain inulin (PFXL) significantly inhibited the short-term retrogradation of wheat starch (WS).•PFXL showed a better effect than long-chain inulin (FXL) in preventing the increase of gel hardness.•During long-term aging, PFXL decreased the migration of free water in WS gel.•Compared to FXL, PFXL prevented retrogradation of amylopectin during long-term storage.