Offering a comprehensive and cutting-edge overview, this book explores how discarded food can be transformed into valuable protein sources and bioactive compounds. After introducing the concept of food waste valorization, it considers the significance of transforming waste into wealth within the framework of a circular economy, setting the stage for detailed discussions of various aspects of protein extraction and application. By emphasizing practical applications and transformative potential, it aims to inspire a new wave of innovation and sustainability in managing food waste, ultimately contributing to a healthier planet and a more efficient food system. This is a forward-thinking resource that bridges the gap between research and industry, ideal for researchers, entrepreneurs and scientists working at the intersection between the two.