Regulation of retrogradation and textural properties of mung bean starch gels during storage: Role of cooling rate

The effect of different average cooling rates on the retrogradation, microstructure, and texture of mung bean starch gels during 14-day storage at 4 °C was investigated. Rapid cooling (6.50 °C/min) significantly delays the retrogradation process, as evidenced by a 24–36 % reduction in retrogradation enthalpy (ΔH) loss and a 30–40 % decrease in gel toughness compared to slow cooling (2.98 °C/min). Rapid cooling restricts the formation of ordered crystalline domains, leading to disordered networks with increased porosity. Initially, this rapid cooling results in a lower total number of junctions (TNJ) and junction density (JD), which contributes to a looser gel structure. However, as storage time progresses, both TNJ and JD gradually increase, accompanied by a gradual increase in hardness and toughness. Furthermore, TNJ and JD can also account for variations in break distance. Mechanistically, rapid cooling delays retrogradation by kinetically controlling the reorganization of starch chains, effectively preserving the structural integrity of the gels during storage. These findings provide a novel method for modulating the retrogradation and texture of starch gels through cooling rate control.