A rheological test to assess the ability of food inks to form dimensionally stable 3D food structures

A method is presented to screen food inks for their ability to form 3D structures of sufficient rigidity to be considered dimensionally stable. The storage modulus and damping factor extracted from an amplitude sweep in oscillatory shear measurements of a food ink are used to characterise rigidity. The storage modulus appears in a dimensionless number representing the ratio of deformation force due to food-structure weight to the force countering deformation due to food-ink rigidity. This dimensionless number and the damping factor form the axes of a graph on which a window of dimensional stability is defined assuming a structural-deformation limit of 5% over 1 h. The graph shows that food inks with higher damping factors require higher storage moduli to form dimensionally stable 3D structures. The window allows food inks with appropriate rigidity to be selected or, given food-ink rheology, suitable structural heights to be estimated to form dimensionally stable 3D structures.