Multi-scale structural changes and mechanistic analysis of wheat starch gels with common proteins in short-term retrogradation at low temperature

The effect and mechanism of four common proteins (egg white powder (EWP), soy protein isolate (SPI), whey protein isolate (WPI) and wheat gluten (WG)) on the short-term retrogradation of wheat starch (WS) gels were investigated in terms of apparent characteristics, structural properties and crystallization (short-range orderliness and long-range orderliness). The recrystallization style of all gel samples were mainly B-type crystal. Compared to the control group, WS gels with EWP, SPI, and WG delayed formation and aggregation of the double helix structure. This delay was accompanied by a reduction in hydrogen bonding, short-range and long-range orderliness, thereby reducing the enthalpy of retrogradation. EWP and SPI reduced the increase rate of hardness during retrogradation. EWP also had the potential to alter the nucleation mode of recrystallization. Thus, EWP, SPI, and WG had the potential to inhibit the retrogradation of WS gels. Conversely, WPI could reduce the short-range orderliness during retrogradation, and WS gels with WPI exhibited higher hardness, long-range orderliness, and enthalpy of retrogradation during storage.