Optimizing upcycled agri-food by-products: A novel approach to developing functional plant-based meat analogues with enhanced textural and nutritional profiles

The rapid evolution of the global alternative protein market demands continuous innovation to improve the sensory, structural, and ecological attributes of plant-based meat analogues. While current formulations rely heavily on ultra-processed soy and pea protein isolates, this study introduces a sustainable, circular economy-driven framework by upcycling nutrient-dense agri-food by-products—specifically Brewers’ Spent Grain (BSG) and sunflower oil press cake—into structured plant proteins. Utilizing High-Moisture Extrusion Cooking (HMEC), we systematically investigated the effects of varying moisture levels (55–65%), barrel temperature profiles (120–140°C), and by-product incorporation rates (10–30 wt.%) on the macrostructural formation and cross-linking density of the protein matrices.

Texture Profile Analysis (TPA) and sensory panel evaluations demonstrated that an optimal blend of 20% upcycled by-products with pea protein concentrate closely replicated the fibrous chewiness and tensile strength of conventional poultry tissue. Microstructural imaging via Scanning Electron Microscopy (SEM) confirmed the formation of highly aligned, continuous anisotropic protein strands without phase separation. Furthermore, the inclusion of sunflower press cake significantly enhanced the essential amino acid score and increased the total dietary fiber content by 42% compared to commercial benchmarks, effectively addressing the traditional nutritional deficits of meat alternatives. These findings demonstrate that integrating agri-food side-streams into extrusion workflows not only drastically reduces raw material costs and processing carbon footprints but also delivers clean-label, high-nutrition meat analogues tailored to meet stringent European consumer preferences for sustainable, premium-quality dietary alternatives.

Keywords: Plant-Based Meat Analogues; High-Moisture Extrusion; Upcycled Agri-Food Side-Streams; Circular Bioeconomy; Functional Foods