Effects of Storage Time on Steamed Bread Quality and Gluten Protein Structure

The effects of storage time on the quality of steamed bread and the structure of gluten protein were investigated by determining the specific volume, the texture characteristics, the microstructure, the secondary structure of gluten and the moisture distribution. The results showed that with the increase of storage time, the specific volume of steamed bread gradually decreased. The hardness, stickiness and chewiness of steamed bread increased gradually, elasticity, cohesiveness and recovery decreased gradually. The contents of α-helix and β-turn in gliadin decreased, the contents of β-sheet and random coil increased. The contents of β-fold and random coils in glutenin increased, the contents of α-helix and β-turn gradually decreased. Both T21 and T22 decreased, the proportion of bound water gradually increased. The gluten protein and starch granules in steamed bread gradually break off, the gluten network also gradually collapsed and surface structure of steamed bread also changed from smooth to uneven.