NUTRITIONAL AND FUNCTIONAL CHARACTERISATION OF ALTERNATIVE FEED AND FOOD INGREDIENTS: EMPHASIS ON HEMP-BASED PRODUCTS, CO-PRODUCTS, MICROALGAE AND CULTURED MEAT

The growth of the world population has led to an increase in demand for food, particularly meat and dairy products, further intensifying livestock production, resulting in an enhanced use of grain for animal feed and competition with crops for direct human consumption. In parallel, over time, the livestock sector has exerted considerable pressure on resources, with large areas of arable land dedicated to food cultures and grazing, as well as high water use. This highlights the urgent need for action with multidisciplinary approaches. For this reason, the aims of this thesis were to evaluate the nutritional and functional potential of alternative plant-based products, including hemp, cardoon, and camelina, by analysing their antioxidant properties, bioactive peptide profiles, and their impact on the quality of animal-derived products. It also aimed to optimize the culture medium of microalgae, in particular for Euglena gracilis to enhance its functional profile while investigating the risks of nanoplastics and microplastics contamination during cultivation under heterotrophic conditions. Additionally, the research sought to address key challenges in cultured meat production by developing alternatives to fetal bovine serum, scalable biofabrication methods, and the integration of waste-derived components to support cell proliferation and differentiation. These objectives collectively aimed to advance sustainable, ethical, and innovative practices in the agri-food sector. Hemp based-products and their co-products have demonstrated high nutritional and functional profiles, as observed following in vitro digestion and solvent extraction methods. In support of this, an in vivo trial, conducted on laying hens, showed how the inclusion of a hemp co-product of up to 9% (leaves, non-standard hemp seeds, hulls and stems) improved performance while increasing the functional and nutritional profile of the eggs. However, it is important to emphasise that their applicability in the livestock sector requires a multidisciplinary approach, evaluating not only the positive effects on animal health but also taking into account limiting factors such as availability, high cost and variability. Among the various possible alternatives, microbial proteins, in particular microalgae, are strong candidates. In particular, as demonstrated in this thesis, the modulation of the culture medium of E. gracilis, cultivated under heterotrophic conditions, led to improvements in the nutritional and functional profile. This result represents a milestone in the formulation of a product that can be specifically designed for the needs of farm animals. However, the widespread use of plastic bioreactors for microalgae cultivation poses potential health challenges for the user. Indeed, plastics can release micro- and nanoplastics into the culture medium, which can accumulate in the biomass and enter the food chain, potentially impacting animal and human health. Finally, a possible alternative of recent interest is the production of cellular foods. In this field, cultured meat is certainly the most discussed. Although scientific research has tried to find answers to the main questions concerning the production process and its sustainability, many open issues still remain. Among these, alternatives to foetal bovine serum that can guarantee the growth, proliferation and differentiation of muscle cells through an ethical and sustainable process deserve further and necessary investigation. As demonstrated in this thesis, possible alternatives involve co-products of food (e.g. whey proteins), which can support the viability, proliferation and differentiation of C2C12 murine muscle cells. Although further studies are needed, all these alternatives represent fundamental steps towards the creation of resilient and environmentally friendly food systems. Despite promising results, further research is needed to standardise these approaches and address unresolved issues, ensuring their feasibility in the food, feed and livestock sectors. The exploration of these alternative proteins is in line with global efforts to create sustainable food systems and mitigate the environmental challenges posed by traditional agricultural practices.