Structural, textural and sensory impact of sodium reduction on long fermented pizza.

The aim of this study was to elucidate the microstructural, textural, and sensory impact of sodium reduction and its partial replacement by potassium chloride in pizza dough and crusts prepared by a traditional long fermentation process. For the first time, macrostructural changes in texture were elucidated and quantified by a novel protein network analysis. The fermentation process exerted a strengthening effect in the doughs, allowing to reduce sodium up to 25% without any negative impact on texture. Sodium reduction by 15% did not cause any significant textural changes in pizza crusts and partial replacement by KCl resulted in a strengthened dough and firmer pizza crust. The use of toppings masked the effect of lowering the sodium content, allowing to increase the reduction level from 15% to 35%. A reduction of NaCl by 25% with an addition of KCl achieved high acceptance in the sensory evaluation.

Protein network analysis - A new approach for quantifying wheat dough microstructure.

Clarification of wheat dough functionalities by visualizing the protein microstructure demands a precise image analysis, which is still challenging. Thus, a novel method for quantifying dough microstructure called protein network analysis (PNA) was established in this study. Hereby, absolute morphological attributes such as junctions' density, branching rate, end-point rate, and lacunarity quantify and characterize the strength of a network. The method was validated in a large range of varying microstructural shapes by increasing the bulk water concentration. In addition, the effect of two different magnifications (objectives with various numerical apparatus) was studied. Resulting values of the branching rate showed a significant linear decrease (R2=0.97) by ~40% for both magnifications indicating a decrease in connectivity and cohesion within the network. Rheological measurements, used as reference methods confirmed the loss of a network structure with increasing water addition (e.g. G* decreased by 89%). Additionally, significant correlations between both methods validated the innovative image analysis PNA. With this new approach of image analysis, effects of additives, varying dough ingredients or changing process conditions on gluten network - the most structure-relevant component in wheat dough - can be quantitatively identified, and targeted functionalities can be controlled.