UPCYCLING FOOD BY-PRODUCTS INTO NUTRIENT-RICH FUNCTIONAL INGREDIENTS

The increasing generation of food processing by-products has emerged as a major challenge for global food systems, raising concerns regarding resource efficiency, environmental sustainability, and economic losses. At the same time, these underutilized streams represent a substantial reservoir of nutrients, bioactive compounds, and functional ingredients that can be reintegrated into food value chains. As the principles of sustainability and circular bioeconomy gain prominence, the valorization and upcycling of food by-products have become important strategies for reducing waste while creating value-added products.

This chapter explores the opportunities and challenges associated with transforming plant- and animal-derived food processing residues into functional ingredients for contemporary food applications. Particular attention is given to major by-product categories, including fruit and vegetable pomace, cereal brans, oilseed meals, dairy whey, and seafood processing residues. Their compositional characteristics, nutritional attributes, bioactive constituents, and technological functionalities are examined to illustrate their potential as ingredients for next-generation food products.

The chapter further discusses recent advances in upcycling technologies, including green extraction techniques, biotechnological approaches, and innovative non-thermal processing methods. These technologies are evaluated in terms of extraction efficiency, preservation of bioactivity, scalability, and industrial applicability. In addition, emerging applications in functional foods, clean-label formulations, and products designed to support gut health are highlighted, together with considerations related to sensory quality, safety, consumer acceptance, and regulatory compliance.

Finally, the broader sustainability implications of food by-product utilization are addressed through perspectives on life cycle assessment, resource circularity, and bioeconomy development. By outlining current achievements, existing limitations, and future research needs, this chapter presents food by-product upcycling as a key pathway toward more resilient, sustainable, and resource-efficient food production systems.