From Insects to Functional Food Ingredients: A Targeted Narrative Review of How Processing Technologies Influence Nutritional Quality, Digestibility, Bioactivity, Safety and Consumer Acceptance

Edible insects can be converted into flours, defatted powders, protein concentrates, isolates, hydrolysates, lipid fractions and chitin-rich ingredients. This targeted narrative review of 45 cited sources, including 18 original studies in the core processing-outcome synthesis, examines how processing affects the safety, nutrient retention, digestibility, techno-functionality, sensory quality, cost and sustainability of these ingredients; it is not an exhaustive or systematic review. Nutritional contribution, techno-functional performance and substantiated physiological or health-related functionality are distinguished and potential bioactivity is not treated as proof of a human health benefit. Blanching, boiling, roasting, convective drying, milling, pressing, defatting, extraction, hydrolysis and fermentation are classified as established operations; freeze-drying as an established low-temperature process; and microwave and infrared heating, ultrasound, pulsed electric fields, high-pressure processing and cold plasma as emerging or intensification technologies. Moderate heating may improve microbial control and protease accessibility, whereas excessive heat may reduce amino-acid availability, solubility, foaming and emulsification. Reductions in total counts are distinguished from validated pathogen lethality, and food safety includes biological, chemical, physical and allergenic hazards. In the European Union, market access depends on novel food authorisations that are specific to species, life stage, process and product. The review proposes a conceptual species–process–product framework that links process selection to product application, safety validation, sensory acceptance, industrial feasibility and regulatory compliance; this framework is informed by, but has not been validated against, the reviewed evidence.