Shrimp Processing By-Products as Food Ingredients: Sensory-Functional Co-Optimization, Ingredient Readiness, and Design Strategies.

Shrimp processing side streams are increasingly considered circular resources, yet their food use remains limited by a gap between compound recovery and ingredient-level validation in target food systems. This review examines how head and cephalothorax fractions, shells, trimming residues, hepatopancreas-associated materials, and process liquors can be directed toward fit-for-purpose ingredient platforms, including protein hydrolysates, savory bases, carotenoid-rich oils, chitin/chitosan systems, and multifunctional composites. Food use is constrained by sensory liabilities and matrix performance, including marine, rancid, ammoniacal, sulfurous, fermented, and bitter notes, as well as solubility, emulsification, water/oil binding, color stability, oxidative resistance, and target-matrix compatibility. Accordingly, processing strategies such as controlled hydrolysis, fermentation, defatting, Maillard-assisted flavor tailoring, encapsulation, and selected physical technologies are evaluated here as application-oriented interventions. To support industrial translation, we organize these factors into a staged ingredient-readiness framework linking feedstock classification, stabilization history, conversion route, aroma- and taste-active profiling, structure‒function behavior, prototype-food validation, safety and regulatory feasibility, scale-up feasibility, and commercial benchmarking. By emphasizing application-specific specifications, this review distinguishes ingredient readiness from laboratory recovery success. Future priorities include standardized reporting, sensomics-guided mechanisms, batch consistency, allergen and regulatory management, benchmarking against commercial ingredients, and pilot-scale validation. This application-oriented perspective may help clarify when shrimp by-products are likely to become standardized, multifunctional, and commercially viable ingredients for circular food systems.