Extrusion-based 3D food printing can be used as an alternative structuring technique to traditional extrusion processing for creating meat-like structures. This study focused on 3-D food printing to generate structures analogous to meat by using various combinations of texturized pea protein fibrils, microbial Single Cell Protein (SCP) and hydrocolloids locust bean gum and/or sodium alginate. Simple moulding was utilized as benchmarking to better understand the 3D printing-induced structural effects. To gain understanding of the interactions between proteins of different origin (plant and SCP) and with hydrocolloids, structural, textural and rheological properties were analysed. Oscillatory stress sweeps of all printing pastes revealed elastic-dominant rheological behaviour (G' 4000-6000 Pa) with a defined yield stress (25-60 Pa) explaining their printability and shape stability. X-ray microtomography of ion-crosslinked analogues showed a printing-induced preferential alignment of fibrils in the direction of nozzle movement, while moulding led to a random orientation. Textural characterization via bi-directional cutting tests demonstrated higher cutting force in transversal (F_T) over longitudinal (F_L) direction in 3D-printed samples and equal forces in moulded samples. The anisotropy index (AI = F_T/F_L) of printed samples ranged between 1.4 and 2.5, indicating anisotropic texture, and 0.8-1 for moulded samples indicating isotropic texture. This study demonstrated the applicability of paste-extrusion in generating anisotropic structures analogous to meat by process-induced fibril alignment. The results support further development of 3D food printing technology in design of sustainable meat alternatives resembling whole-muscle meat.

The aim of the study was to evaluate consumer perceptions toward customized snacks produced with a Healthy Snack Machine (HSM) prototype, at-site of the purchase and consumption. The present study had a multi-disciplinary approach including both snack product and HSM development (hardware and user interface). Snack development included both instrumental (viscosity, colloidal stability) and sensory characterization (by trained sensory (N = 10) and consumer (N = 55) panels) of spoonable and drinkable, oat- and dairy-based snack products, fortified with protein and/or dietary fiber. The protein and fiber addition reduced viscosity in spoonable products but did not affect the consistency of drinkable samples. Oat-based samples differed from dairy-based in multiple attributes in sensory profiling. In consumer sample testing, sample odor and taste were the most and least preferred aspects, respectively. In the snack machine testing, a qualitative consumer study (N = 33) showed that the HSM was easy to use, the user interface was clear, the ordering process was quick, and the participants were interested in using the HSM in the future. The snack choices (spoonable/drinkable and dairy/oat base) made by the consumers were distributed equally, but the berry-flavor was preferred over cocoa and vanilla. The most common HSM usage scenarios were “between work/school and hobbies” and “in transit from one place to another”.