Edible Insect Proteins: Why Processing Decides Whether Bugs Become Better Food

Edible insects have long been pitched as the protein source of the future, but a comprehensive new review argues that the real story is far more complicated than simply grinding up crickets and mealworms. Writing in the Journal of Agriculture and Food Research, Chi Hao Nguyen and Duy H. Truong synthesise evidence published since 2015 to show that the usefulness of insect proteins is not an intrinsic property of the insects themselves. Instead, it emerges from a chain of decisions running from raw-material selection through processing, protein structure and functionality to performance in specific foods, with safety, allergenicity and consumer acceptance acting as constraints at every step.

The review begins with a sober assessment of sustainability claims. Insects such as Tenebrio molitor, Acheta domesticus, Locusta migratoria, Alphitobius diaperinus, Bombyx mori and Hermetia illucens offer high feed conversion efficiency, short growth cycles and lower land requirements than conventional livestock, and many species contain all essential amino acids in nutritionally significant amounts. Yet the authors stress that environmental advantages only materialise when the entire production chain is optimised, including rearing substrate, energy use for temperature control, killing method and drying. Insect proteins should therefore be treated as conditional alternatives whose benefits depend on well-controlled systems rather than assumed by default.

Even measuring how much protein an insect contains turns out to be surprisingly tricky. The conventional nitrogen-to-protein conversion factor of 6.25 can overestimate protein content because insect biomass contains nitrogen from chitin and other non-protein compounds. Janssen and colleagues proposed a lower factor of approximately 4.76 for mealworm, lesser mealworm and black soldier fly larvae. Reported values also depend on whether composition is expressed on a fresh-weight or dry-matter basis, and on the developmental stage, rearing diet and processing history of the material. Digestibility adds another layer: in vitro studies show mealworm and cricket proteins can achieve digestibility figures of 79 to 99 percent and favourable DIAAS scores, but these outcomes shift with heat treatment, defatting and chitin reduction, making digestibility a processing-dependent property rather than a fixed species trait.

Processing is where the review’s central framework comes into play. Pretreatments such as killing, blanching, drying, grinding and defatting establish the initial state of the biomass, and each involves trade-offs. Blanching improves microbial and enzyme control but can unfold proteins and promote aggregation that reduces extraction efficiency. Freeze-drying limits thermal damage but is costly, while microwave and hot-air drying scale better yet risk Maillard reactions, lipid oxidation and protein denaturation. Defatting enriches protein and limits oxidation, since residual lipids rich in polyunsaturated fatty acids generate rancid aldehydes such as hexanal and nonanal, but solvent contact and duration can alter protein conformation and downstream recovery. Quantitatively, defatting raised Tenebrio molitor flour from 57.8 to 64.6 percent protein while cutting fat to 2.8 percent, and lifted Hermetia illucens flour from 34.7 to 44.9 percent protein.

Protein recovery routes then diverge sharply. Dry fractionation by milling and sieving is simple and low in water and chemical use, but yields fractions still loaded with lipids, chitin, ash and pigments, making them better suited to bakery and snack applications than to refined functional roles. Alkaline solubilisation followed by isoelectric precipitation boosts purity and yield, but extreme pH can trigger denaturation, browning and unwanted structural changes. Assisted technologies offer further options: ultrasound cavitation disrupts tissues and aggregates, improving extraction yields by 35 to 94 percent in sonicated silkworm pupae, while high-pressure processing increased protein solubility in Protaetia brevitarsis seulensis up to an optimum of 200 megapascals before the benefit declined. No single technology wins outright; the authors insist processing should be designed backwards from the target food.

Post-recovery modification tailors proteins to specific functions, and here the quantitative evidence is striking. Enzymatic hydrolysis of migratory locust protein raised solubility from as low as 10 percent to 55 percent and foamability to 326 percent at pH 3. Cricket hydrolysates reached emulsifying activity indices of up to 32 square metres per gram, compared with 6.23 for defatted cricket flour. But hydrolysis illustrates what the authors call the protein-functional modification dilemma: excessive cleavage weakens interfacial films, releases bitter hydrophobic peptides and, crucially, does not reliably eliminate allergenic epitopes unless proteolysis is extensive, on the order of 60 to 85 percent degree of hydrolysis needed to disrupt major allergens such as tropomyosin. Fermentation offers another route, with fungal fermentation of cricket powder increasing solubility by roughly 20 percent and water-holding capacity from 2.17 to about 2.62 grams per gram, though it demands careful microbiological control.

Application studies show that ingredient form must match product structure. Bread is highly sensitive because insect flour dilutes the gluten network that traps fermentation gases, producing compact crumbs and darker colour, so insects work best as supplementary ingredients. Biscuits, crackers, muffins and protein bars tolerate higher inclusion levels because their quality depends less on gas retention. Extruded snacks sit in between: cricket powder at 12.5 to 15 percent could qualify products as protein sources, but 7.5 percent was recommended to preserve expansion and texture. In meat analogues, insect proteins perform best as complementary fractions within hybrid systems. High-moisture extrusion of insect and soy protein concentrates showed that around 15 to 40 percent insect protein could match the cutting properties of a soy control, while substituting 10 percent of soy protein isolate with cricket powder actually enhanced fibrous anisotropy, although higher levels produced brittle, incoherent extrudates. Three-dimensional printing studies found that pellet fractions of cricket and mealworm at 15 percent gave the best shape fidelity and post-print texture, underlining that fractionation, not the insect species alone, is the controlling design variable.

Liquid foods impose the strictest demands. Beverages require high solubility at acidic pH to avoid sedimentation and cloudiness, making whole insect flours largely unsuitable and pushing formulators toward soluble concentrates and hydrolysates. Consumer testing of mealworm protein shakes identified a rejection threshold of 14.6 percent mealworm content only among blind-tasting participants; health- and sustainability-framed groups showed no comparable threshold, suggesting communication can shift tolerance, though it cannot rescue poor sensory quality. Bioactive peptides add another dimension: cricket hydrolysates produced by microwave-assisted enzymatic hydrolysis showed ACE-inhibitory IC50 values of 0.096 milligrams per millilitre and DPP-IV-inhibitory values of 0.27, better than conventional hydrolysis. The authors caution, however, that these results come from chemical and in vitro enzyme assays and cannot be equated with proven antihypertensive or glycaemic effects in humans.

Safety and regulation complete the picture. Insect biomass can carry Enterobacteriaceae, Salmonella, Listeria, Staphylococcus aureus and spore-forming bacteria, so hurdle-based strategies combining blanching, drying, water-activity control and hygienic handling are essential. Chemical hazards such as mycotoxins and heavy metals depend on rearing substrate, meaning circular production using food-industry side streams requires rigorous contaminant monitoring. Allergenicity remains a critical concern because insects share conserved pan-allergens, including tropomyosin and arginine kinase, with crustaceans, molluscs and house dust mites; one observational study found 73 percent of crustacean- and mite-sensitised patients showed IgE reactivity to recombinant black soldier fly tropomyosin. In the European Union, novel food authorisations are species- and process-specific, as illustrated by the approved partially defatted house cricket powder, which carries mandatory allergen labelling. The review’s conclusion is clear: no single insect ingredient will suit every product. Commercial success will depend on standardised, application-specific ingredients whose processing history, functional performance, safety profile and sensory character are validated together, from raw material to finished food.

Subject of Research: Processing-structure-function relationships in edible insect proteins for food applications

Article Title: Designing edible insect proteins for food applications: Processing-Structure-Function relationships, product performance and safety trade-offs

Article References: Nguyen, C. H., & Truong, D. H. (2026). Designing edible insect proteins for food applications: Processing-Structure-Function relationships, product performance and safety trade-offs. Journal of Agriculture and Food Research, 31, Article 103340. https://doi.org/10.1016/j.jafr.2026.103340

Image Credits: AI Generated

DOI: 10.1016/j.jafr.2026.103340

Keywords: edible insects, insect protein, food processing, protein functionality, allergenicity, food safety, meat analogues, protein hydrolysates, novel foods, sustainable protein, techno-functional properties, consumer acceptance