Although some people attest that crab is not safe for human consumption yet, several researchers and nutritionists claim that it is nutritionally safe to consume. They attributed this claim to crab’s rich vitamins, protein and amino acids constituent. Nutritionists also agree that crab is an essential addition to a flourishing and healthy eating plan.
Crab is a crustacean with 2 stalked eyes, broad carapace and 5 pairs of legs that thrive mainly on seashores. Although not every crab lives in the sea as some live in freshwater while others live on land. Crustacean belongs to an infraorder of Brachyura distinguished by a short projecting tail or abdomen.
It breathes through gills, possesses jointed shells known as the exoskeleton and normally grows by moulting or shedding off its old shell to make way for a new shell growth. The hard exoskeleton is made up of calcium carbonate. Crab is omnivorous in nature being that it can feed on a variety of food, both plant and animal origins such as fungi, plankton, algae, clams, shellfish, detritus, molluscs, bacteria, worms, fish and other crustaceans.
Crab has a good sense of smell, sight, taste and can feel pain due to its sensory nerves. It is quite active and can be easily distinguished due to its complex behavioural style. A typical crab is a decapod because it has 10 jointed legs. The 2 frontal legs are the claws known as pinchers or pincers. Crabs usually antagonise one another and tend to fight one another to get what they want. Some crab species excavate the mud or sand for hiding, defence, resting, copulating, laying eggs and for hatching eggs.
There are approximately eight hundred and fifty crab species found in both seashores, freshwater, terrestrial and semi-terrestrial habitats. Some types and species of crab include;
The Atlantic ghost crab, crab of the seashore (littoral crab), striped shore crab, swimming crab, blue swimmer crab (Portunus pelagicus), the Columbus crab (Planes minutus), callinectes amnicola, horseshoe crab, sersema specie, red king crab (Paralithodes camtschaticus), mud crab, dungeness crab, Red Klippenkrabbe, red swimming crabs (Portunus haanii), halloween crab: Gecarcinus quadratus, sodononates Africana, coconut crab (Birgus latro), Japanese spider crab, snow crab, the Southern European crab (Potamon fluviatile), brown crab (Cancer pagurus), blue crabs (Callinectes sapidus), Carboniferous Imocaris, hermit crab, sally lightfoot crab from South America, fiddler crab, porcelain crabs, crab lice and octopode Africana (African ghost crab) etc.
Nutritional Values of Crab
Identifying the nutritional values of crab meat is essential due to the beneficial impacts these nutrients can contribute to human health. Kala and Chandran (2014) confirm that crab is an excellent source of carbohydrates, protein and many other essential minerals thus suitable for boosting human nutrition.
These researchers assessed the proximate and mineral components of some crabs brought from the freshwater, marine, estuarine and other terrestrial environments. Their findings show that the marine crabs Portunus pelagicus exhibited higher protein content of 23.23±0.22 while the lowest protein level of 13.23±0.02 was recorded in Cardisoma carnifex crabs.
Barytelphusa cunicularis crabs exhibited a minimum carbohydrate constituent of 1.1±0.02% while the land crab C. carnifex recorded a maximum carbohydrate constituent of 1.32±0.01%. Basically, the study showed that estuarine and marine crabs contain higher protein unlike the freshwater and land crabs. Furthermore, other minerals such as potassium, calcium, magnesium and sodium were higher in estuarine and marine crabs while iron and copper were observed to be higher in terrestrial and freshwater crabs.
Their study is in support of Naczk et al., (2007) work, which reported that crab meat is an excellent source of minerals especially phosphorus, calcium, iron, zinc, potassium and copper but with low levels of carbohydrates and fat. Crab also contains chitin, which is the main constituent in the exoskeleton of arthropods and a fibrous substance made up of polysaccharides. It is also a rich source of vitamin A, vitamin B, vitamin C, vitamin B12, omega-3 fatty acids, sterol, selenium and chromium.
16 Outstanding Benefits of Crab
It is noteworthy that not all crabs are edible for example; Callinectes amnicola is edible unlike ocypode Africana, which is mostly used as bait. Live crab is very delicate and as such should always be handled with care. Failure to do so can easily weaken the crab, cause it to be discoloured and chalky in appearance thus making it unpalatable.
Different countries have different crab cuisines, for example, it can be roasted, cooked whole, deep-fried, steamed, skewered, boiled or baked. According to Savad and Raghavan, (2001), crab meat has delectable taste and it ranks third after shrimps and lobsters due to its distinctive savour.
Some crab species can be eaten whole for example, soft-shell crab while only the legs and claws are eaten in some other species, for example, snow crab. Crabmeat or crab meat, which is the meat present in a crab can be used for preparing assorted dishes such as crab cakes, crab linguine, cajun crab cakes, garlic crab legs, Singaporean chili crab, steamed lemongrass crab legs, crab dip, crab rangoon, crab parmesan dip, crab stew, baked crab, crab stuffed mushrooms, crab stuffed chicken breast, crab salad, crab frittatas, cajun crab soup, remoulade sauce a la New Orleans, shrimp and crab bisque, crab tacos, crab stuffed flounder, crab omelet, shrimp and crab enchilada.
The best part of the crab meat is the leg. Note that cooked crab meat easily gets spoiled and as such should be consumed within a space of short time after preparation. Otherwise, it should be refrigerated or kept frozen until it is ready for consumption. Besides, crabmeat shouldn’t be left where it can be easily contaminated with bacteria and germs as it is a conducive medium for bacterial growth.
Promotes Healthy Teeth and Bone
Due to crab’s constituent of calcium and phosphorus, it is suitable for maintaining healthy teeth and bone development. It is also suitable for growing children in other to prevent osteomalacia and rickets as supported by Kala and Chandran (2014).
Osteomalacia is the softening of bones caused as a result of calcium or vitamin D deficiency while rickets is a disease condition of children caused as a result of vitamin D deficiency, marked by impaired calcification, distortion and softening of the bones thereby leading to bow legs. Furthermore, the chitin in crab helps to promote osteogenesis i.e. the formation of bone.
Crab intake helps to decrease the risk of cancer attack. Studies reveal that crab is suitable for preventing the onset of cancer due to its rich constituent of selenium. The antioxidant selenium in crab inhibits the carcinogenic effects of mercury, arsenic and cadmium that can cause tumour growth and cancer attacks in human beings. In fact the higher the selenium level, the lower the risks of cancer.
Improves Blood Sugar Metabolism
Due to the high amount of chromium in crab, it is suitable for individuals that have insulin resistance. This is attributed to the fact that the chromium in crab helps to improve the blood sugar metabolism thus reducing the blood glucose levels in the body. The chromium in crab facilitates the action of insulin thus preventing the onset of diabetes.
Production of Surgical Equipment
Being an excellent source of chitosan and chitin, Subashinghe (1999) attests that crab is suitable for producing surgical equipment such as; surgical thread, gauzes, biomedical beads, medical fabrics, wound dressing, antifungal agents, dialysis membrane and antibacterial materials. This is attributed to the biodegradability potentials of chitosan and chitin thus they can easily wear away during the wound healing process.
Regulates the Cholesterol Level
The chromium nutrient found in crab helps to increase the HDL (good cholesterol) level in the body. Increasing the good cholesterol in the body helps to minimise the risk of heart attacks, strokes, circulatory and coronary diseases. Moreover, the sterol found in crab helps to inhibit the absorption of possible cholesterol and fat consumed in other food products. The omega 3 fatty acids in crab help to lower the level of triglycerides and bad cholesterol LDL (low-density lipoproteins) that usually block the arterial walls.
Ideal for Pregnant Women
Nutritionists agree that crab is safe for consumption by pregnant women but this should be in moderation. Being an excellent source of vitamin B and omega 3 acids, crab is highly recommended during pregnancy. Howbeit, pregnant women are encouraged to cook this crustacean very well in other to destroy parasites and bacteria that could possibly affect unborn babies. Pregnant women are also encouraged to consume mainly crabs with the lowest mercury content such as king crab and freshwater crab.
Facilitates Wound Healing
Crab is an excellent source of chitin and as such suitable for facilitating and accelerating wound healing process. According to Thirunavukkarasu and Shanmugam (2009), the chitosan in crab acts as a wound-healing accelerator as well as helps to protect a wound from bacterial invasion through suppression of bacterial proliferation.
Supports the Cardiovascular System
Being a rich source of omega-3 fatty acids, crab meat is recommended for supporting the cardiovascular system. It helps to promote the healthy functioning of the heart thus preventing heart-related diseases such as heart failure, heart attacks. The phosphorus in crab aids in the contraction of the heart muscle.
The high amount of omega-3 fatty acids in crab aid brain development and boosts memory. Crab intake can also help to prevent anxiety and depression.
Prevents Nutritional Deficiencies
Kala and Chandran (2014) emphasised that crab is a suitable supplement of protein and minerals needed to support and balance human nutrition. Thus consuming edible crabs is essential for preventing nutritional deficiencies.
Crab is an excellent source of antioxidants such as selenium. This nutrient prevents oxidative damage to the body tissues and cells thereby reducing the risk of cancer attacks.
Prevents Blood Clotting
The omega-3 fatty acids found in crab are essential for preventing blood clotting.
Regulates the Blood Pressure
The potassium and omega-3 fatty acids present in crab are essential for regulating the blood pressure level.
Aids Balanced Weight
Crab is low in carbohydrates, fat and calories thus essential for healthy functioning of the body parts and for maintaining a healthy weight.
Crab contains anti-inflammatory properties due to its high constituent of omega-3 fatty acids. It helps to prevent and reduce arthritic pain.
Some individuals are allergic to crab meat thus such people should refrain from consuming it. Crab allergies include; skin rash, anaphylaxis, food poisoning and if not properly treated can lead to death.
DISCLAIMER This post is for enlightenment purposes only and should not be used as a replacement for professional diagnosis and treatments. Remember to always consult your healthcare provider before making any health-related decisions or for counselling, guidance and treatment about a specific medical condition.
1] Bayliss, J. (2002), The East Usambara tree-hole crab (Brachyura: Potamoidea: Potamonautidae) – a striking example of crustacean adaptation in closed canopy forest, Tanzania. African Journal of Ecology 40, pp. 26-34.
2] Begum, M., Shah, M. M. R., Mamun, A. A. and Alam, M. J. (2009), Comparative study of mud crab (Scylla serrata) fattening practices between two different systems in Bangladesh. Journal of Bangladesh Agricultural University 7(1): pp. 151–156.
3] Falinska A. M., Bascoul-Colombo C., Guschinaa A., Good M. and Harwood J. L. (2012), The role of n-3 dietary polyunsaturated fatty acids in brain function and ameliorating Alzheimers disease: Opportunities for biotechnology in the development of nutraceuticals. Biocatalysis and Agric. Biotechnology 1,pp.159-166.
4] Gökoğlu N and P Yerlikaya, (2003) Determination of proximate composition and mineral contents of blue
crab (Callinectes sapidus) and swim crab (Portunus pelagicus) caught off the Gulf of Antalya. Food
Chem, 80: pp. 495–498.
5] Lee E., Meyer S. P. and Godber J. S. (1993), Minced meat crab cake from blue crab processing by-products development and sensory evaluation. J. Food. Sci, 58: pp. 99–103.
6] Kala, J. K. L. and Chandran, M. (2014), Chemical composition of Brachyuran crabs from various environments, International Journal of Pharma and Bio Sciences, 5(4), pp.612 – 620.
7] Kucukgulmez, A., Celik, M., Yanar, Y., Ersoy, B. and Cikrikci, M. (2006), Proximate Composition and Mineral Contents of the Blue Crab (Callinectes sapidus) Breast Meat, Claw Meat and Hepatopancreas
International Journal of Food Science Technology, 41, pp.1023-1026.
8] Murphy M. G., Skonberg, D., Camire, M. E., Dougherty, P. M., Bayer R. C. and Briggs, J. L. (2003), Chemical composition and physical properties of extruded snacks containing crab-processing by-product. Food Agric, 83: pp. 1163–1167.
9] Murugesan, R., P. Soundarapandian and Manivannan, K. (2008), Effect of Unilateral Eyestalk Ablation on the Biochemical changes of edible portunid crab Charybdis lucifera (Fabricus). Journal of Fish. Aqua. Science, 3(1): pp.82-86.
10] Muzzarelli, R.A. (2009), Chitins and chitosans for the repair of wounded skin, nerve cartilage and bone, Carbohydrate Polym.76: pp. 167-82.
11] Naczk M., Williams J. and Brennam K., et al. (2007), Compositional characteristics of green crab (Carcinus sapidus), Food Chemistry, 88: pp. 429-434.
12] Ravichandran S., Rameshkumar G, Velankanni S, Kaliavarathan G. (2009), Variation in fatty acid composition of the crab Portunus sanguinolentus in different development stages. Natl Acad Sci Lett, 32: pp. 123-128.
13] Savad, A. M., and Raghavan, P. R. (2001), Mud crab culture and fattening techniques, status and prospects. Seafood Export Journal, 32, pp. 25-29.
14] Skonberg, D. I. and Perkins, B. L. (2002) Nutrient composition of green crab (Carcinus maenus) leg meat and claw meat. Food Chemistry 77(4): pp. 401–404.
15] Subasinghe, S. (1999), Chitin from shellfish waste health benefits over-shadowing industrial areas, Infofish International, 3/99: pp. 58-65.
16] Thirunavukkarasu and Shanmugam (2009), Extraction of chitin and chitosan from mud crab scyla tranquebarica (Fabricius, 1798), International Journal on Applied Bioengineering, Vol.4, No.2, pp.31-33.
17] West, K., Cohen, A. & Baron, M. (1991). Morphology and behaviour of crabs and gastropods from Lake Tanganyika, Africa: implications for lacustrine predator-prey coevolution. Evolution 45, 589-607.
18] Pixabay (2016), All images from Pixabay.