Soft wheat flour doughs were prepared with different levels of salt (NaCl) or baking soda (NaHCO₃). Oscillation rheology, elongational viscosity, and extensibility of doughs were tested to evaluate the effect of salt and baking soda on the physical properties of doughs. Furthermore, a series of physical–biochemical analytical techniques were used to investigate gluten polymerization in doughs, including zeta potential analyzer, Fourier transform infrared spectroscopy (FTIR), spectrophotometer, and reversed-phase high-performance liquid chromatography (RP-HPLC). The addition of high levels of NaHCO₃ (1.0% fwb), either by itself or in combination with NaCl, increased dough strength, elongational viscosity, and viscoelasticity. RP-HPLC results demonstrated macromolecular aggregation of gluten proteins in the presence of NaCl or NaHCO₃. The addition of NaHCO₃ or NaCl also decreased both free sulfhydryl content and random-coil structure of gluten isolated from the doughs. Overall, NaCl and NaHCO₃ induced the changes of molecular conformation of gluten, which impacted the physicochemical qualities of soft wheat flour dough. This study provides a better understanding of salt and baking soda functionality in the formation of soft flour dough, which will support the searching of feasible sodium reduction strategies in soft flour bakery products.

中文翻译：

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氯化钠和碳酸氢钠对软小麦粉面团理化性质和面筋聚合的影响

用不同含量的盐（NaCl）或小苏打（NaHCO ₃）制备软质小麦粉面团。测试了面团的振荡流变性，伸长粘度和延展性，以评估盐和小苏打对面团物理性能的影响。此外，还使用了一系列物理-生化分析技术来研究面团中的面筋聚合，包括zeta电位分析仪，傅里叶变换红外光谱（FTIR），分光光度计和反相高效液相色谱（RP-HPLC）。添加高含量的NaHCO ₃（1.0％fwb）本身或与NaCl组合使用，可提高面团强度，伸长粘度和粘弹性。RP-HPLC结果表明在NaCl或NaHCO ₃存在下面筋蛋白的大分子聚集。NaHCO ₃或NaCl的添加也降低了从面团中分离出来的面筋的游离巯基含量和无规卷曲结构。总体而言，NaCl和NaHCO ₃引起面筋分子构象的变化，影响了软质小麦粉面团的理化性质。这项研究更好地理解了软粉面团中盐和小苏打的功能，这将有助于在软粉烘焙产品中寻找可行的钠还原策略。