Effect of wheat gluten on the quality of corn steamed bread prepared by modified corn flour and its frozen storage stability

Although corn steamed buns, as coarse-grain foods, are rich in dietary fiber and trace elements, the traditional production process has several drawbacks, such as producing corn buns with a rough texture and dull color, which restrict their acceptance by consumers. This study optimizes the raw material ratio through single-factor experiments to increase the palatability and overall acceptability of corn steamed buns. With increasing gluten proportions, the hardness, gumminess and chewiness of the corn steamed buns first decreased to 2368.58, 1258.12 and 940.36, respectively, and then increased. In contrast, their water-holding capacity, L* value, specific volume, height-diameter ratio, elasticity, cohesiveness and resilience first increased to 3.46, 74.59, 1.75, 0.70, 0.84, 0.55 and 0.21, respectively, and then decreased. When the amount of added gluten reached 20%, the sensory score of the steamed buns was the highest, reaching 84.10 points. With increasing frozen storage time, the water-holding capacity of the corn steamed buns decreased; the water loss rate increased; the bound water content decreased; the relaxation time, weakly bound water content, free water content and frozen water content increased; the elasticity, cohesiveness and resilience of the steamed buns decreased; the hardness, gumminess and chewiness increased; and the quality of the steamed buns gradually decreased. During the fourth week of freezing, the gluten network structure inside the steamed buns was severely damaged, causing the hardness of the corn steamed buns to sharply increase to 4280.33, the elasticity to decrease to 0.66, and its quality to sharply decline. As mentioned above, corn buns are of better quality when the gluten content is 20% and when the freezing storage time does not exceed 4 weeks.