Steaming treatments affect the quality of instant dough sheets through moisture migration and the structural properties of starch and protein

Abstract

Instant dough sheets (IDS) as an improvement on traditional food products face issues in industrial production such as long rehydration time and poor quality. This paper examines the water migration pattern and structural changes of starch and protein during the steaming process of raw dough sheets (RDS) and analyzes the impact of these changes on the rehydration properties and quality of IDS. The results showed that steaming decreased the mobility of hydrogen protons. After steaming, the predominant form of water (more than 60%) was weakly bound water. Magnetic Resonance Imaging (MRI) images revealed that water migrated from the surface to the interior of the RDS and redistributed hydrogen protons. Meanwhile, steaming reduces the viscosity of starch and enhances the degree of gelatinization and thermal stability of starch. After steaming, a strengthened gluten network and a stable protein secondary structure were observed in RDS. This ameliorated the cooking qualities (cooking loss ≤8.15%, rehydration time ≤358s) and the texture properties. Hence, proper steaming can significantly enhance the quality of IDS by increasing the proportion of bound water and reinforcing the gluten network of RDS. Its purpose is to establish a theoretical foundation for the development of superior IDS.