Screening of different flours for 3D food printing: Optimization of thermomechanical process of soy and rye flour dough

3D food printing allows the development of personalized food, but it is necessary to diversify the printable recipes to propose a varied food offer. The objective of this project was to explore the printability potential of different flours and to optimize a thermomechanical process (mixing and heating of water and flour) to ensure good print quality. A bibliographic study of 25 flours and an experimental screening of five flours was conducted. Thanks to the previous steps, soy and rye flour were selected because of their interesting nutritional value and their printability potential. An experimental design (10 trials) for each flour showed a significant impact of the process parameters studied (percentage of water content and duration of the thermomechanical treatment) on print quality. The reverse engineering approach demonstrated that the optimal water content is similar for both flour (Soy: 59%, Rye: 60%), but the optimal duration of the thermomechanical treatment is quite different (Soy: 27 min, Rye: 22 min).

Industrial relevance text

Interest in 3D food printing has continued to grow in recent years. Products with different flavors, shapes and textures have been proposed in many studies. However, print quality is not always easy to predict and to obtain, especially when faced with nutritional or functional constraints. In our study, we developed a 3-steps approach (two screening steps including bibliographic and experimental method and then one optimization step) to propose new edible ink combining interesting nutritional composition and good print quality. To achieve this goal a design of experiments based on two process parameters (water content and duration of thermomechanical treatment) was conducted and a predictive model was established for soy and rye flours. The reverse-engineering method allowed determining the process parameters to use to ensure good print quality and stability of 3D-printed products. This approach could be applied for the development of new edible ink using other flours or integrating different ingredients.