Novel Protein Resources for Sustainable Food Systems: Integrating Protein Chemistry, Nutritional Evaluation, and Food...

The growing demand for sustainable and high-quality protein sources has accelerated the development of novel proteins from plant, microbial, and alternative resources. However, existing reviews are often descriptive and lack an integrated framework linking protein source characteristics, extraction strategies, structural properties, and functional and nutritional outcomes. This review provides a comprehensive and integrative analysis of novel protein resources, classified as underutilized by‑product proteins, alternative established proteins, and emerging platforms, by systematically connecting protein chemistry, nutrition, and processing technologies. Three interconnected challenges are identified as inefficient extraction and purification, incomplete structure-function understanding, and fragmented safety and nutrition frameworks. A decision‑oriented framework is proposed to guide the selection of protein sources and extraction/fractionation strategies based on source‑specific structural constraints and targeted functional properties. Comparative quantitative tables summarize compositional characteristics, digestibility (DIAAS/PDCAAS), techno‑functional performance, and technology readiness levels of different novel proteins. Structure-function relationships are further elucidated to explain how processing‑induced modifications influence solubility, emulsification, and gelation behavior. Nutritional quality, safety risks, and regulatory considerations are critically assessed, distinguishing intrinsic hazards from process‑related risks and highlighting mitigation strategies. The integration of these aspects enables the establishment of a systematic workflow from raw material selection to application‑oriented protein design. This review provides a practical reference for optimizing the utilization of novel proteins and supports their translation into scalable and sustainable food systems.