Extracts of blue crab

 Blue crab
(Callinectes sapidus)

Description

• Blue crab is a marine/estuarine crustacean whose meat is used as a lean, high-protein seafood ingredient. Commercial products include fresh, pasteurised, frozen and canned crab meat, as well as value-added preparations (cakes, patties, fillings).

• Edible meat is obtained mainly from the body (lump/backfin) and claws, sometimes also from legs.

• The ingredient is typically a white to off-white, slightly translucent meat, with a delicate, sweet, mildly briny flavour and a tender, flaky texture.

Indicative nutritional values (per 100 g cooked blue crab meat)

(Typical composition for cooked blue crab; values may vary by cut, origin, and processing.)

• Energy: ≈ 80–95 kcal

• Water: ≈ 75–78 g

• Protein: ≈ 18–21 g

• Total fat: ≈ 0.5–1.5 g

  • first occurrence: SFA/MUFA/PUFA = saturated / monounsaturated / polyunsaturated fatty acids; total fat is low and the profile is relatively rich in unsaturated fat, with only a small SFA fraction and a meaningful share of marine n-3 PUFA, generally favourable for cardiometabolic health as part of a balanced diet.

• Carbohydrates: ≈ 0–1 g (virtually negligible)

• Cholesterol: ≈ 55–80 mg

• Sodium (natural + process): typically ≈ 250–400 mg (can be higher in salted/canned products)

• Key micronutrients (approximate):

  • Vitamin B12: very high (often > 200–300% of daily value per 100 g)

  • Niacin (B3), B6, folate: small–moderate amounts

  • Minerals: phosphorus, selenium, zinc, copper, and, in marine-caught crabs, some iodine.

Key constituents

• Proteins and amino acids

  • Blue crab meat is protein-dense and contains all essential amino acids, making it a complete protein.

  • Studies on blue crab composition show breast and claw meat with ~19 g protein/100 g and particularly high levels of lysine, alanine and glutamic acid + glutamate, which support umami taste and nutritional quality.

• Lipid fraction

  • Overall fat content is low, but the residual fat includes marine n-3 fatty acids, especially EPA/DHA (eicosapentaenoic / docosahexaenoic acid), alongside MUFA and SFA.

  • This lipid profile is generally considered favourable compared to many terrestrial animal fats, provided the product is not heavily enriched with added fats.

• Minerals and vitamins

  • Excellent source of phosphorus, selenium and sodium, with useful contributions of zinc, copper, magnesium and sometimes calcium if small shell fragments are present.

  • High vitamin B12 and moderate niacin support normal energy metabolism and neurological function.

• Other components

  • Small amounts of chitin and carotenoid pigments (especially astaxanthin) may be present, particularly in meat close to the shell.

Production process

(Overview for food-grade blue crab meat and derived ingredients.)

• Harvesting and reception

  • Blue crabs are captured via traps, pots, trawls or small-scale gears in coastal and estuarine environments (native western Atlantic; invasive in parts of the Mediterranean and other regions).

  • Crabs are landed alive or freshly killed, chilled on ice and transported quickly to processing plants.

• Cooking and picking

  • Whole crabs are washed and heat-treated (typically steam or boiling) to cook the meat and loosen it from the shell.

  • After cooling, meat is manually or mechanically picked from body, claws and legs. Mechanical extraction is sometimes used to recover additional meat from by-products (picking-room scraps).

• Sorting and grading

  • Meat is graded into categories such as jumbo lump, lump, backfin, special, claw, etc., based on particle size, location and colour.

• Further processing

  • For pasteurised refrigerated products: meat is packed in cans/tubs, sometimes with minimal brine, then pasteurised and rapidly cooled.

  • For frozen meat: quick freezing (often IQF blocks or trays).

  • For canned products (shelf-stable): more intense thermal processing in sealed containers.

  • For ingredient use (e.g., minced or comminuted crab): meat may be minced, mixed, vacuum-packed and pasteurised or frozen.

Physical properties

• Appearance: white to off-white flaky meat; claw meat may be slightly darker or more orange-tinted due to pigments.

• Texture: tender, flaky but cohesive, able to hold together in cakes/patties when bound with small amounts of starch or crumbs.

• Odour and flavour: fresh, sweet, marine/briny; off-odours (ammoniacal, sour, oxidised) indicate deterioration.

• Water activity: high in fresh/pasteurised and thawed products; lowered in dried or intermediate-moisture preparations.

Sensory and technological properties

• Sensory profile

  • Characteristic sweet, delicate flavour with light marine salinity; less “fishy” than some finfish.

  • Pronounced umami due to amino acids (glutamate, aspartate) and nucleotides.

• Technological functionalities

  • Binding and structure: combines well with egg, starches and crumbs to form stable crab cakes, patties, dim sum fillings.

  • Water-holding capacity: moderate; sufficient to maintain juiciness if not overcooked or over-pressed.

  • Heat behaviour: overcooking leads to dry, fibrous meat; gentle heating preserves moisture and tenderness.

Food applications

• Home and foodservice

  • Core ingredient in crab cakes, croquettes, fritters, crab salads, pasta dishes, risottos, soups, chowders, bisques, stews and stuffed vegetables.

  • Used in sandwiches, sushi, cold appetisers and canapés.

• Food industry

  • Ingredient in chilled and frozen ready meals, seafood mixes, filled pastas, savoury pastries and pies.

  • Used in soups, sauces, spreads, dips, surimi-type products and flavour concentrates/broths containing crab.

  • Mechanically recovered minced crab meat from by-products can be incorporated into value-added products and flavour bases.

Nutrition & health

• Blue crab meat provides high-quality complete protein with relatively low energy and fat per 100 g.

• The residual lipid fraction contributes marine n-3 PUFA, including EPA/DHA, which are associated with cardiovascular and cognitive benefits when consumed in adequate amounts as part of total seafood intake.

• Rich vitamin B12 content supports normal neurological function and red blood cell formation; selenium and zinc support antioxidant defence and immune function.

• Low carbohydrate content and modest calorie density make blue crab suitable for energy-controlled, low-carb or higher-protein diets, provided that sauces and coatings are also controlled.

Portion note:

• Typical culinary portions:

  • 60–90 g cooked crab meat as part of a mixed dish (pasta, risotto, salad).

  • 100–150 g cooked crab meat as main protein portion, depending on overall meal design and energy needs.

Allergens and intolerances

• Blue crab is a crustacean shellfish and therefore a major food allergen in many jurisdictions. Fish- and shellfish-allergic individuals may react differently: some tolerate finfish but react to crustaceans, and vice versa.

• Major identified crab allergens include tropomyosin and arginine kinase, which can trigger reactions from mild oral symptoms to anaphylaxis in sensitised subjects.

• For allergic consumers, any form of blue crab (fresh, cooked, processed, hydrolysates) must be considered unsafe.

• Processed foods containing blue crab must declare crustacean presence according to local allergen labelling regulations.

Quality and specification (typical topics)

• Compositional criteria

  • Moisture, protein, fat, ash, and salt (especially for brined/canned products).

  • Limits for TVB-N (total volatile basic nitrogen) and TMA-N (trimethylamine) as freshness indicators.

• Sensory and physical

  • Odour: clean, sweet, marine; no sour or ammonia notes.

  • Appearance: bright, not slimy, minimal shell fragments, absence of black spots from melanosis.

  • Texture: tender, flaky, not mushy or stringy.

• Microbiological

  • Compliance with limits for total aerobic counts, Enterobacteriaceae, and absence of pathogens (e.g., Salmonella, Listeria monocytogenes, Vibrio spp. depending on jurisdiction).

• Contaminants

  • Heavy metals (e.g., Hg, Cd, Pb, As) and organic pollutants (dioxins, PCBs) must meet regulatory limits for crustaceans.

Storage and shelf-life

• Fresh, chilled meat (non-pasteurised):

  • 0–2 °C; typically a few days shelf-life; rapid use needed.

• Pasteurised refrigerated crab meat:

  • Kept at 0–4 °C, often several weeks to a few months unopened (depending on process); shorter once opened.

• Frozen crab meat:

  • ≤ −18 °C; typical shelf-life 6–18 months, depending on glaze, packaging and fat content; avoid repeated thaw–freeze cycles to limit texture damage and oxidation.

• Canned crab:

  • Shelf-stable at ambient temperature for 1–5 years, subject to can integrity and best-before date.

After opening any refrigerated or canned product, keep chilled and use within a few days following manufacturer instructions.

Safety and regulatory

• Processing plants operate under GMP/HACCP systems, with critical control points typically at:

  • raw material reception (live/freshness, origin, contamination risks),

  • time–temperature control during cooking and cooling,

  • prevention of cross-contamination,

  • pasteurisation/retorting parameters,

  • packaging integrity.

• Blue crab and other crustaceans must comply with:

  • fisheries and resource management rules for harvesting,

  • food safety legislation (microbiological criteria, contaminants, additives),

  • mandatory allergen labelling for crustacean shellfish.

Labelling

• Typical ingredient declarations:

  • “blue crab meat”, sometimes with grade (e.g. “jumbo lump blue crab meat”, “claw meat”).

• Finished products should clearly indicate:

  • the common/market name of the species (e.g. “Blue crab (Callinectes sapidus)” where required),

  • crustacean allergen presence (e.g. in a “Contains: Crab (crustacean)” statement),

  • net weight, best-before/expiry date, storage conditions, batch/lot number, producer/packer details.

Troubleshooting (quality and process)

• Ammonia or strong “fishy” odour

  • Cause: loss of freshness, microbial spoilage, excessive storage time or temperature abuse.

  • Action: reject batch, improve chilling, reduce time from catch to processing.

• Mushy texture

  • Cause: overcooking, enzyme activity, freeze–thaw damage or extended storage.

  • Action: optimise cooking times, ensure rapid chilling, minimise storage and refreezing, adjust glazing/packaging.

• Shell fragments in meat

  • Cause: inadequate picking or mechanical separation settings.

  • Action: improve manual trimming, sieving/sorting, and operators’ training; adjust equipment.

• Oxidative rancidity or off-flavours

  • Cause: lipid oxidation during storage (especially frozen/canned products with higher fat).

  • Action: improve oxygen barrier, glazing, temperature control; consider antioxidants where permitted.

Sustainability and supply chain

• In its native range (U.S. Atlantic and Gulf coasts, Mexico), blue crab supports valuable commercial fisheries; in several non-native regions (e.g., Mediterranean, Black Sea) it is considered an invasive alien species with ecological and economic impacts.

• Sustainable management aims to:

  • maintain or rebuild stocks in native areas,

  • use harvesting as a control tool in invaded ecosystems while limiting bycatch and habitat damage,

  • integrate blue crab into biorefinery approaches, valorising meat, shells and by-products (chitin/chitosan, pigments, protein hydrolysates) to reduce waste.

• Processing plants should manage shell and organic waste and high-load effluents (high BOD/COD) via suitable wastewater treatment and by-product valorisation (e.g., animal feed, fertiliser, biogas).

• Robust logistics and FIFO stock rotation help preserve quality, limit losses and improve overall resource efficiency.

Main INCI functions (cosmetics and related uses)

• There is no common cosmetic INCI entry specifically labelled “Blue crab extract”, but derivatives from crab and other crustaceans (e.g., chitin, chitosan, glucosamine, marine collagen) are used in personal care:

  • film-forming, moisturising and conditioning agents in skin and hair products,

  • viscosity modifiers and stabilisers in gels and creams.

• These cosmetic ingredients are produced via separate extraction and purification chains from shells and other by-products, and are distinct from food-grade crab meat.

Conclusion

Blue crab meat is a lean, protein-rich seafood ingredient with a delicate, sweet flavour and low fat content, providing complete protein, high vitamin B12 and valuable minerals at a relatively low caloric cost. Its technological properties allow incorporation into a broad range of products, from simple crab cakes to complex ready meals and flavour bases. At the same time, blue crab is a priority allergen and requires strict allergen management and labelling. In both native and invaded regions, well-designed fisheries and processing strategies can support sustainable use, valorise by-products and limit waste, making blue crab both a culinary resource and a potential tool for managing invasive populations.

Mini-glossary

• SFA/MUFA/PUFA – saturated / monounsaturated / polyunsaturated fatty acids; in blue crab the overall fat level is low and relatively enriched in unsaturated PUFA (including n-3) compared with many terrestrial animal fats, which is generally considered favourable when part of an overall balanced diet.

• EPA/DHA – eicosapentaenoic acid / docosahexaenoic acid; long-chain n-3 fatty acids typical of marine species, associated with cardiovascular and neurocognitive benefits when consumed in adequate amounts through seafood.

• BV (biological value) – index of how efficiently dietary protein is used for body protein synthesis; crab protein has high BV thanks to its complete essential amino acid profile.

• GMP/HACCP – good manufacturing practices / hazard analysis and critical control points; structured systems to ensure hygienic, controlled, and traceable production of seafood products including pasteurised and canned crab.

• BOD/COD – biochemical / chemical oxygen demand; measures of organic and oxidisable load in processing wastewater (e.g., from crab picking and cooking), important for designing and monitoring effluent treatment.

• FIFO – first in, first out; stock-rotation principle whereby oldest batches are used first to maintain freshness, reduce spoilage and limit quality loss along the cold chain.

References__________________________________________________________________________

Arena R, Manuguerra S, Gonzalez MM, Petrosillo E, Lanzoni D, Poulain C, Debeaufort F, Giromini C, Francesca N, Messina CM, Santulli A. Valorization of Blue Crab (Callinectes sapidus) By-Products into Antioxidant Protein Hydrolysates for Nutraceutical Applications. Animals (Basel). 2025 Oct 11;15(20):2952. doi: 10.3390/ani15202952. 

Abstract. The Atlantic blue crab (Callinectes sapidus) is an opportunistic invasive species in the Mediterranean that is negatively affecting biodiversity, fisheries, and tourism. In Italy, it is appreciated for its good meat quality, but the processing yield is low (21.87 ± 2.38%), generating a significant amount of by-products (72.45 ± 4.08%), which are underutilized. Valorizing this biomass is in line with circular economy principles and can improve both environmental and economic sustainability. This study aimed to valorize Atlantic blue crab by-products (BCBP), producing protein hydrolysates and assessing their in vitro bioactivities, in order to plan applications in animal food and related sectors. BCBP hydrolysates were obtained by enzymatic hydrolysis using Alcalase and Protamex enzymes. The treatment with Alcalase resulted in a higher degree of hydrolysis (DH = 23% in 205 min) compared to Protamex (DH = 14% in 175 min). Antioxidant activity of the hydrolisates was evaluated through DPPH, ABTS, reducing power and FRAP assays, as well as in vitro test in fibroblasts (HS-68). At 10 mg/mL, hydrolysates from both enzymes exhibited the maximum radical scavenging activity in DPPH and ABTS assays. In HS-68 cells, 0.5 mg/mL hydrolysates protected against H2O2-induced oxidative stress, showing a cell viability comparable to cells treated with 0.5 mM N-acetyl cysteine (NAC), as an antioxidant. Statistical analyses were performed using one-way ANOVA followed by Student-Newman-Keuls (SNK) or Games-Howell post hoc tests, with significance set at p < 0.05. Overall, both enzymes efficiently hydrolyzed BCBP proteins, generating hydrolysates with significant antioxidant activity and cytoprotective effects. These results demonstrate the potential to produce high-quality bioactive compounds from BCBPs, suitable for food, nutraceutical, and health applications. Scaling up this valorization process represents a viable strategy to improve sustainability and add economic value to the management of this invasive species, turning a problem in a resource.

Tekin S, Pazi I. POP levels in blue crab (Callinectes sapidus) and edible fish from the eastern Mediterranean coast. Environ Sci Pollut Res Int. 2017 Jan;24(1):509-518. doi: 10.1007/s11356-016-7661-6.

Abstract. Organochlorinated pesticides and Aroclors were measured in the muscle of two edible fish species (gray mullet, sea bream) and blue crab, collected from eastern Mediterranean coast in 2013. The concentration of organochlorinated pesticides (OCPs) and Aroclors in biota samples which were collected at six sites ranged from 1.0-8.6 and 9-47.5 ng g-1 wet weight, respectively. Total DDT concentrations in seafood samples were compared to tolerance level established by the US Food and Drug Administration (FDA); the concentrations were detected below the tolerence level. Health risk assessment was conducted related to the consumption of chemically contaminated seafood. The estimated daily intake of OCPs calculated by using the estimated daily fish consumption in Turkey was far below the acceptable daily intake as established by FAO/WHO. Our data indicated that consumption of blue crab, gray mullet, and sea bream collected from the Mediterranean coast of Turkey could pose "no risk" for human health in terms of OCPs.

Conti F, Pulido-Rodriguez LF, Chemello G, Cattaneo N, Resente M, Parisi G, Olivotto I, Zarantoniello M. The Role of Dietary Fatty Acids in Modulating Blue Crab (Callinectes sapidus) Physiology, Reproduction, and Quality Traits in Captivity. Animals (Basel). 2024 Nov 17;14(22):3304. doi: 10.3390/ani14223304.

Abstract. The invasive blue crab is challenging the Mediterranean basin, progressively declining local populations. This reflects a lower prey availability and suitability of dietary nutrients (mainly n-3 polyunsaturated fatty acids, PUFA). The present study aimed to challenge blue crab males and females with a feed source low in n-3 PUFA with respect to one showing a proper fatty acid profile and to investigate the responses in terms of growth, welfare, lipid characterization of target tissues, and reproductive status. Blue crabs were divided into three groups as follows: (i) Marine: crabs fed sardinella (Sardinella aurita) fillet for 60 days; (ii) Mix: crabs fed bovine heart for the first 40 days and sardinella fillet for the following 20 days; and (iii) Terrestrial: crabs fed bovine heart for 60 days. The diet did not alter the health status but reflected the fatty acid profile of muscle and ovary of the blue crabs. In each group, males and females showed a proper hepatopancreas structure, with comparable levels of lipid reserves. This properly supported gonad maturation in both sexes. However, males and females from the group fed the terrestrial diet were characterized by reduced body weight, revealing that blue crabs prioritize reproductive investment rather than growth by directing crucial nutrients to reproductive organs when a suboptimal diet is available.

Migaou M, Macé S, Maalej H, Marchand L, Bonnetot S, Noël C, Sinquin C, Jérôme M, Zykwinska A, Colliec-Jouault S, Maaroufi RM, Delbarre-Ladrat C. Exploring the Exopolysaccharide Production Potential of Bacterial Strains Isolated from Tunisian Blue Crab Portunus segnis Microbiota. Molecules. 2024 Feb 7;29(4):774. doi: 10.3390/molecules29040774. 

Abstract. The blue crab (BC) Portunus segnis is considered an invasive species colonizing Tunisian coasts since 2014. This work aims to explore its associated bacteria potential to produce anionic exopolysaccharides (EPSs) in order to open up new ways of valorization. In this study, different BC samples were collected from the coastal area of Sfax, Tunisia. First, bacterial DNA was extracted from seven different fractions (flesh, gills, viscera, carapace scraping water, and three wastewaters from the production plant) and then sequenced using the metabarcoding approach targeting the V3-V4 region of the 16S rDNA to describe their microbiota composition. Metabarcoding data showed that the dominant bacterial genera were mainly Psychrobacter, Vagococcus, and Vibrio. In parallel, plate counting assays were performed on different culture media, and about 250 bacterial strains were isolated and identified by sequencing the 16S rDNA. EPS production by this new bacterial diversity was assessed to identify new compounds of biotechnological interest. The identification of the bacterial strains in the collection confirmed the dominance of Psychrobacter spp. strains. Among them, 43 were identified as EPS producers, as revealed by Stains-all dye in agarose gel electrophoresis. A Buttiauxella strain produced an EPS rich in both neutral sugars including rare sugars such as rhamnose and fucose and uronic acids. This original composition allows us to assume its potential for biotechnological applications and, more particularly, for developing innovative therapeutics. This study highlights bacterial strains associated with BC; they are a new untapped source for discovering innovative bioactive compounds for health and cosmetic applications, such as anionic EPS.

Grey EK, Chiasson SC, Williams HG, Troeger VJ, Taylor CM. Evaluation of Blue Crab, Callinectes sapidus, Megalopal Settlement and Condition during the Deepwater Horizon Oil Spill. PLoS One. 2015 Aug 13;10(8):e0135791. doi: 10.1371/journal.pone.0135791.

Abstract. The Blue Crab, Callinectes sapidus, is a commercially, culturally, and ecologically significant species in the Gulf of Mexico (GOM), whose offshore stages were likely impacted by the Deepwater Horizon oil spill (DWH). To test for DWH effects and to better understand the planktonic ecology of this species, we monitored Callinectes spp. megalopal settlement and condition at sites within and outside of the spill extent during and one year after the DWH. We tested for DWH effects by comparing 2010 settlement against baseline data available for two sites, and by testing for differences in settlement and condition inside and outside of the spill extent. We also developed time series models to better understand natural drivers of daily settlement variation (seasonal and lunar trends, hydrodynamics, wind) during 2010 and 2011. Overall, we found that neither megalopal settlement nor body weight were significantly reduced at oiled sites, but that high unexplained variation and low statistical power made detection of even large effects unlikely. Time series models revealed remarkably consistent and relatively strong seasonal and lunar trends within sites (explaining on average 28% and 9% of variation, respectively), while wind and hydrodynamic effects were weak (1-5% variation explained) and variable among sites. This study provides insights into DWH impacts as well as the natural drivers of Callinectes spp. megalopal settlement across the northern GOM.