Valorization of Coffee By‐Products for Food Applications: Functional Ingredients, Packaging Materials, and Safety Assessment

Coffee is the world's second most consumed beverage. Its production, processing, and consumption generate large quantities of by‐products, including spent coffee grounds, silverskin, and husks. These by‐products are rich in dietary fiber, cellulose, polyphenols, and other bioactive compounds, yet they are largely underutilized and commonly discarded or used as low‐value animal feed. This review focuses on the extraction and food‐related utilization of valuable components from coffee by‐products. Specifically, it summarizes their major functional constituents, extraction technologies, applications as functional food ingredients, and potential use in food packaging materials, together with current knowledge regarding their safety. In contrast to previous reviews that have focused on individual by‐products or broad cross‐sector valorisation, this review specifically examines the food application chain from component extraction to ingredient and packaging development. The reviewed literature indicates that coffee by‐products represent promising sources of dietary fiber, antioxidants, and phenolic compounds with considerable potential for incorporation into functional foods and sustainable packaging materials. Among the available recovery approaches, green extraction technologies show particular advantages in improving extraction efficiency while reducing environmental impact. However, challenges remain regarding process standardization, regulatory approval, and comprehensive safety evaluation. Bioconversion, biofuel production, and other non‐food utilization pathways are beyond the scope of this review. This work provides a comprehensive reference for researchers and food industry stakeholders seeking to promote the sustainable and safe utilization of coffee by‐products in food systems and highlights future directions for their industrial application.