Towards meltable plant-based cheese alternatives: Processing oil and fat in zein-pea hybrids to acquire a thermoreversible hydrogel

• Integrated solid fats showed a more cheese-like microstructure compared to oil • Solid fat is needed as a lubricant while melting the zein-pea matrix • LAOS at 60°C as a useful tool to predict melting • Lissajous plots of zein-pea hybrids showed a melting behavior similar to Mozzarella Plant-based cheese alternatives face challenges in replicating the sensory, protein content and functional properties of cheese, such as texture, creaminess and melting. This work focuses on zein-pea hybrids, as previous research showed that blending zein and pea protein forms a hydrogel that is promising to mimic cheese. The first part of this study investigated the addition of oil/fat to achieve meltable plant-based alternatives. Thermoreversible or melting behavior was analyzed using the modified Schreiber-test (180°C, 10 min) and the temperature sweep (= SAOS), while the microstructure was examined by confocal laser scanning microscopy (= CLSM). The type of oil/fat was investigated in a pure protein matrix, whereas the emulsification was analyzed in a matrix containing protein and potato starch. The microstructure was examined by confocal laser scanning microscopy (= CLSM). Among the zein-pea hybrids, formulations containing solid fats such as coconut fat or canola-oleogel produced the most cheese-like microstructures. Moreover, the fat should be added at low temperatures (20 °C). Thermoreversible or melting behavior was analyzed using the modified Schreiber-test (180°C, 10 min) and the temperature sweep (oscillatory rheology). Large, non-emulsified fat crystals acted as lubricants during melting, increasing protein mobility and promoting flow. As a result, a flow degree similar to Mozzarella was achieved. In the second part of this work, selected samples from the first part were assessed for structural changes during heating using large-amplitude oscillatory strain (= LAOS) at 60 °C. Melting behavior was predicted by the slope n of the deformation γ and the complex viscosity η*.d, Zein and pea protein proved suitable for tailoring the matrix towards a cheese-like melting behavior. Future plant-based cheese alternatives can benefit from the microstructural changes of zein and pea protein.