复配小麦粉组成对冷冻馒头复蒸品质的影响及作用机制

Effect of Compount Wheat Flour Composition on the Re-steaming Quality of Frozen Steamed Bread and Its Underly Mechanism

摘要:

目的探讨复配小麦粉组成对冷冻馒头复蒸后品质的影响及作用机制。方法 采用不同配比的小麦复配粉制作馒头并进行冷冻处理，测定复蒸后不同馒头的比容、质构、麦谷蛋白大聚体（GMP）质量、游离巯基质量摩尔浓度、蛋白质相对分子质量等指标。结果 小麦复配粉的蛋白质质量分数可显著影响面团的热机械性能及馒头的冻藏稳定性。其中，蛋白质质量分数较高的MF1所制面团具有较高的吸水率、面团形成时间与稳定时间，形成的面筋网络结构更完整，GMP质量更高、SDS可萃取蛋白质质量分数更低，能更好地维持冻藏过程中馒头的比容与质构特性。随着冻藏时间的延长，馒头的面筋网络结构出现明显解聚，GMP质量均呈下降趋势，降幅为1.67%~15.12%；游离巯基质量摩尔浓度上升，增幅为2.44%~37.68%；SDS可萃取蛋白质质量分数增加，增幅为9.56%~48.84%；馒头宏观品质表现为比容下降、质构劣变、气孔分布不均等。皮尔逊相关性分析揭示了在冻藏不同阶段，馒头宏观品质指标与蛋白质结构参数、面团流变学特性的内在联系。结论 冷冻馒头复蒸后的品质劣变与小麦组分差异密切有关。在所使用的复配小麦粉体系中，面筋蛋白质量分数、完整的GMP结构与冷冻馒头复蒸后质构特性显著相关。维持面筋网络结构的完整性是缓解冷冻馒头复蒸品质劣变的关键，该研究为冻藏面制品的品质改良提供了理论依据。

Abstract:

ObjectiveThis study aimed to decipher the mechanism through which wheat flour components influenced the deterioration of frozen streamed bread after re-steaming. Method The composite wheat flour samples with different formulations were used to prepare steamed bread, which was then frozen. The specific volume, texture, glutenin macropolymer (GMP) mass, free sulfhydryl molality, and relative molecular mass of proteins were measured after re-steaming of frozen steamed bread. Result The protein mass fraction in the composite wheat flour significantly influenced the thermomechanical properties of dough and the frozen storage stability of steamed bread. The MF1 formulation, with higher protein mass fraction, produced dough with greater water absorption, development time, and stability. Its gluten network structure is more intact, exhibited higher GMP mass and lower mass fraction of SDS-extractable proteins, which better preserved the specific volume and textural properties of steamed bread during frozen storage. As the frozen storage time prolonged, the gluten network underwent significant depolymerization, as manifested by the decreases of 1.67%~15.12% in GMP mass, increases of 2.44%~37.68% in free sulfhydryl molality, and increases of 9.56%~48.84% in mass fraction of SDS-extractable proteins. Correspondingly, the streamed breed exhibited decreased specific volume, deteriorated texture, and uneven pore distribution. Pearson correlation analysis revealed the intrinsic relationships between macroscopic quality indicators, protein structural parameters, and dough rheological properties at different frozen storage stages. Conclusion The deterioration of frozen steamed bread after re-steaming is related to the differences in wheat flour components. In the composite wheat flour systems used, gluten protein mass fraction and complete GMP structure are significantly associated with textural properties of frozen steamed bread after re-steaming. Maintaining the integrity of the gluten network structure plays an important role in slowing down the quality deterioration of frozen streamed bread after re-steaming. This study provides a theoretical basis for improving frozen wheat flour-based products.