Comparing the viscoelastic properties of gelatin and different concentrations of kappa-carrageenan mixtures for additive manufacturing applications

Recent interest in personalisation of food through additive manufacturing has identified a need for more information on the formulation and printability of potential ingredients. The printability of mixtures of gelatin and kappa-carrageenan were investigated, design rules were established to determine whether the materials fit the requirements of the process. The gelling temperatures of the systems (24–42 °C) and the rheological characteristics including: flow profiles, evolution of elastically dominated structures and frequency dependent behavior, were established. The mixtures were subsequently printed at two temperatures, just above and much greater than, their gelling temperatures. Analysis showed rheological behaviour accompanying the coil-helix transition were key to printing the product in a well-defined manner. The printing fidelity was related to the magnitude of the storage modulus, which needed to be greater than 23 kPa, as well as the rapid formation of an elastic network, recovering at least 73% of the maximum storage modulus within 200s.