Effects of high-molecular-weight glutenin subunit on hard-steamed bread quality

Abstract Steamed bread is used as a daily food in many countries worldwide, but the relationship between high-molecular-weight glutenin (HMW-GS) and steamed bread quality is unclear. Two DH populations of common wheat were used to analyze the effects of twelve HMW-GS subunit combinations on the quality traits of steamed bread, including volume traits, physical properties, and sensory evaluation. The mechanism of trait variation was analyzed by combining the microstructure and dough rheological properties. The results showed that in terms of locus effect, the volume and physical properties of steamed bread were Glu-D1> Glu-B1> Glu-A1, and the effect of sensory score on steamed bun was Glu-B1>Glu-D1>Glu-A1. In terms of individual subunit effects, the volume, chewiness, hardness and so on physical properties indexes and sensory scores of subunit 1 steamed bread at Glu-A1locus were higher than those of subunit N, but the number of cells in subunit N steamed bread was more than subunit 1, as well as the cell diameter and wall thickness were smaller than those of subunit 1 steamed bread. The quality of 7+8 and 7+9 subunits steamed bread at the Glu-B1locus was generally better, and the chewiness, number of cells and so on physical properties indexes and sensory scores were significantly higher than those of 6+8 subunit steamed bread, as well as their physical properties indexes were less affected by moisture. The quality of subunits 2+10 and 5+12 steamed bread at the Glu-D1locus was generally better. Moreover, the specific volume, glueyness, number of cells and so on physical properties were significantly better than those of other subunit steamed bread, as well as the physical properties of subunits 2+10, 5+12 and 2+12 were also less affected by moisture. The effect of subunit combination is mainly affected by subunit, and the combination of superior subunits tends to make steamed bread have better quality traits. The subunit combinations (1,7+8,5+12), (N,7+9,2+10) and (1,7+9,5+12) had better physical properties indexes and sensory scores, and the micro-pore structure was dense, uniform and delicate, and the wall thickness was smaller. However, the combinations (N,7+8,2+12), (N,6+8,2+12) and (N,7+9,5+10) were generally lower in physical properties and sensory scores, and the stomatal structure was looser. The results of different subunits of dough rheological properties showed that the protein content, wet gluten content and stability time were the main factors affecting steamed bread's volume and physical properties. Among the rheological properties of dough, the protein content, wet gluten content and stability time of subunits 7+8, 7+9, 2+10 and 5+12 were higher. Therefore, the volume, physical properties and sensory scores of steamed bread containing these subunits were good.