E-Poster Presentation: Development and rheological study of edible biopolymer structures for the purpose of 3D printing extrusion
Authors: Nikolaou, N. E., Karathanos, V. T.
Abstract
Three-Dimensional Food Printing (3DPF) technology constitutes a disruptive new technology that can be applied for product design, personalized nutrition, and further experimentation with various flavor and texture combinations. Knowledge of physicochemical and rheological properties of food components, can provide a reliable framework for the formulation of food inks suitable for 3DFP. This study aims to provide enhanced understanding of the complex food matrix, focusing on the polysaccharides-proteins interaction and their mixtures, providing a wider range of possible materials applicable in 3DFP processes. In this study, food inks were prepared with natural corn and wheat starch combined with pea protein concentrate (55%) with the further addition of hydrocolloids xanthan gum, gum arabic and κ-carrageenan in various proportions and combinations. Prior to the extrusion process the steady and dynamic shear rheological properties and thermal properties of the food-inks were evaluated using a Modular Compact Rheometer and Differential Scanning Calorimetry. Extrusion based 3DFP was performed at room temperature, using a desktop 3D printer with a syringe extrusion system. Developed food-inks, exhibited a shear thinning behavior, that is considered essential for the extrusion process. Storage modulus (G΄) was higher than the loss modulus (G΄΄), suggesting a “weak” gel behavior for all samples while the tangent of phase angle (tanδ) was found less than unity indicating a predominant elastic behavior. Optimal printability for printed square shapes was achieved when the material flow was set between 65-75%, with a print speed of 5 mm/s and a set nozzle height to 1 mm. Wheat starch was overall more suitable, in terms of mechanical properties, for extrusion-based 3D printing, giving more quality and uniform prints while hydrocolloid addition was also found to improve inks printability. The increase in protein concentration had a significant effect on the texture of the final products, resulting in softer and more uniform pastes.
