Dynamic distribution and transition of gluten proteins during noodle processing

Authors: ZHANG, MENGLI - Qingdao Agricultural University; MA, MENG - Qingdao Agricultural University; Yang, Tianbao; LI, MAN - Qingdao Agricultural University; SUN, QINGJIE - Qingdao Agricultural University

Submitted to: Food Hydrocolloids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/13/2021
Publication Date: 2/20/2022
Citation: Zhang, M., Ma, M., Yang, T., Li, M., Sun, Q. 2022. Dynamic distribution and transition of gluten proteins during noodle processing. Food Hydrocolloids. 123:107114. https://doi.org/10.1016/j.foodhyd.2021.107114.
DOI: https://doi.org/10.1016/j.foodhyd.2021.107114

Interpretive Summary: Wheat gluten is the key component to determine the dough characteristics and the quality of wheat flour products. In this study, dynamic distribution and molecular transition of gluten proteins during noodle processing as well as their relationship with texture changes were systematically investigated and quantified. Confocal laser scanning microscopy images and network analysis confirmed that the mixed dough and dough sheeting showed higher gluten junctions and lower lacunarity. The gluten network gradually became orderly and compact after different processing steps such as mixing, resting, rolling, and sheeting, except for the large gaps in the cooked noodles. The mechanical force of mixing and rolling caused partial depolymerization of gluten protein and promoted its repolymerization, thereby forming a well-developed gluten network structure. Heating induced the weakening of hydrogen bonds and hydrophobic interaction. The cooked noodle showed better springiness, while mixed and rested noodle dough exhibited lower hardness. The changes in texture properties were mainly due to changes in the morphology and structure of gluten protein. These results provide a strategy to optimize the processing steps for desired noodle texture.

Technical Abstract: The process of depolymerization and repolymerization of gluten protein in wheat dough affects the dynamic changes of gluten network formation, destruction, and reformation. In this study, dynamic distribution and molecular transition of gluten proteins during noodle processing as well as their relationship with texture changes were systematically investigated and quantified. CLSM images and network analysis confirmed that the mixed dough and dough sheeting showed higher gluten junctions (919.5, 815.0, respectively) and lower lacunarity (9.28, 8.64). SEM images revealed that the gluten network gradually became orderly and compact after different processing steps such as mixing, resting, rolling, and sheeting, except for the large gaps in the cooked noodles. The mechanical force of mixing (step 2) and rolling (step 4) caused partial depolymerization of gluten protein and promoted its repolymerization, thereby forming a well-developed gluten network structure. Each step of the noodle processing was accompanied by a reduction in the content of free -SH, which induced the SH/SS interchange. From step 3 to step 4, the hydrogen bond interaction was strengthened. Heating induced the weakening of hydrogen bonds and hydrophobic interaction. The cooked noodle showed better springiness, while mixed and rested noodle dough exhibited lower hardness. Correlation analysis indicated that the changes in texture properties were mainly due to changes in the morphology and structure of gluten protein. These results provide a strategy to optimize the processing steps for desired noodle texture.