The project aims to reduce agricultural waste by recovering proteins from leaf extracts, typically discarded during crop production. Focus was placed on RuBisCO, an abundant and hypoallergenic protein rich in essential amino acids, making it suitable for human or animal nutrition. Using waste material brings environmental and economic benefits by lowering disposal costs. A simple method was developed to estimate RuBisCO abundance in leaf waste from various plant species, involving fragmentation in water and ultrasonication. Future efforts will focus on isolating the protein for use in the novel food sector, supporting zero waste and circular economy principles.