Effects of low-temperature storage on the characteristics of wheat gluten

ObjectiveThis study aimed to investigate the effects of low-temperature storage (3, 6, 9, 12, 15 days) on the structural and functional properties of gluten proteins, including free sulfhydryl content, secondary structure, water-holding capacity, and rheological properties.MethodsWheat gluten was stored at 4 ℃ and -18 ℃, and changes in free sulfhydryl groups, secondary structure, functional properties and rheological behavior were analyzed.ResultsFree sulfhydryl content increased with storage time, rising by 73.44% at 4 ℃ and 100.42% at -18 ℃ after 15 d compared to the control group. Prolonged low-temperature storage led to a decrease in α-helices and β-sheets, alongside an increase in β-turns and random coils in gluten proteins. Functional properties, including water holding capacity, oil holding capacity, emulsifying capacity, emulsifying stability, foaming capacity, and foaming capacity and stability, declined with extended storage. Additionally, gluten hardness increased, while the viscosity, elasticity, adhesiveness, cohesiveness and recovery gradually decreased.ConclusionLow-temperature storage (4 ℃ and -18 ℃) significantly alters the structural characteristics of gluten proteins, leading to a deterioration in their functional properties.