van der Sman R G M
Wageningen Food Biobased Research, Wageningen University & Research, Netherlands.
Curr Res Food Sci. 2021 Mar 26;4:191-199. doi: 10.1016/j.crfs.2021.03.006. eCollection 2021.
In this paper we describe the chemical reactions of leavening agents in baking biscuits on a sound thermodynamic basis. The model is part in a sequel targetted at physical understanding of biscuit baking with the purpose of reformulation of biscuits with respect to sucrose and sodium levels. The chemical leavening gases, CO2 and NH3, originate from the dissociation of sodium and ammonium bicarbonate. Next to water vapour, these produced gases create gas bubbles in the biscuit dough. The concentrations of the leavening agents and added salt lead to high ionic strength. Consequently, the activities of ions participating in the leavening reaction deviate strongly from ideality. The non-idealities are described using the Pitzer equations. The values of many parameters of the Pitzer model and equilibrium constants are obtained from the strong developed field of CO2 sequestering in ammonia solutions. The model describing the chemical reactions is coupled to a cell model describing the expansion of gas bubbles. Model simulations show that most of the produced gas originates from the bicarbonate, and the ammonium contributes significantly less. The functionality of ammonium as leavening agent is not quite clear, but it may help in reducing sodium levels.
在本文中，我们基于合理的热力学基础描述了烘焙饼干时膨松剂的化学反应。该模型是后续研究的一部分，旨在从物理角度理解饼干烘焙过程，以便在蔗糖和钠含量方面对饼干进行重新配方设计。化学膨松气体二氧化碳和氨气源于碳酸氢钠和碳酸氢铵的分解。除了水蒸气，这些产生的气体在饼干面团中形成气泡。膨松剂和添加盐的浓度导致高离子强度。因此，参与膨松反应的离子活度与理想情况有很大偏差。非理想性用皮泽方程描述。皮泽模型的许多参数值和平衡常数是从氨溶液中二氧化碳封存这一成熟领域获得的。描述化学反应的模型与描述气泡膨胀的单元模型相耦合。模型模拟表明，产生的大部分气体来自碳酸氢盐，铵的贡献要小得多。铵作为膨松剂的功能尚不完全清楚，但它可能有助于降低钠含量。
