Assessment of emerging technologies for the intensification of lupin seed disinfection prior to solid-state fermentation

Lupins are considered a viable plant-based protein source to reduce Europe’s dependence on soybean imports and promote more sustainable agricultural systems. In this context, this thesis aims to evaluate whether they can effectively serve as a sustainable alternative. Various disinfection methods for lupin seeds are investigated and compared, including traditional thermal treatment and emerging technologies such as Pulsed Electric Fields (PEF) and Moderate Electric Fields (MEF), applied under different operating conditions. Thermal treatment proves to be the most effective method, achieving microbial load reductions of up to 3.5 log units at 90 °C. The application of MEF also yields promising results, reducing the microbial load by approximately 2–3 log units at 90 °C, suggesting a potential synergistic effect between temperature and electric fields. Furthermore, the variations in the chemical and techno-functional properties of lupins during fermentation with Pleurotus ostreatus are analyzed, and the impact of PEF pretreatment is assessed. The application of electric fields promotes adequate fungal growth, as indicated by an increase in glucosamine content. Additionally, an increase in phenolic content, antioxidant capacity, and both total and soluble proteins is observed, while lipid content decreases. Saponin content shows an unusual trend, and no alkaloids are detected. Finally, fermentation tends to decrease the emulsifying and water-holding capacities, whereas oil absorption increases. The gelling capacity remains constant in pretreated samples, while it increases in untreated seeds.