Shrimps, exoskeleton

Shrimp, Pandalus jordan r, muscle Brown shrimp, Penaeus aztecus Texas Exoskeleton Muscle Whole Viscera... 

Chitin is a polysaccharide similar to cellulose except that the OH at C-2 is replaced by an acetamido group (CH3CONH). Chitin is the main component of the hard external covering (exoskeleton) of crustaceans such as lobsters, crabs, and shrimp. Like cellulose, the processing of chitin into polymeric products is limited by its insolubility and decomposition without melting. The availability in huge quantities has encouraged many attempts to find commercial applications of chitin, but very few have been found to be economically feasible. 

Barnacle, Elminius modestus-, pyrophosphate granules American lobster, Homarus americanus-, muscle Shrimps, unidentified Exoskeleton Muscle... 

The exoskeletons (protective shells) of insects and some marine organisms, such as crabs and shrimp, are made of chitin, a hard, resilient polysaccharide made of the monosaccharide A acetylglucosamine, as shown in Figure 13.5b. Wood varnish once contained chitin from the exoskeletons of insects. In powdered form, chitin is now finding use as a dietary fiber supplement. 

These carotenoids have a limited distribution and occur as complexes, perhaps in Schiff base linkage, with proteins. Astaxanthin protein complexes with absorption maxima ranging from 410 nm to 625 nm or more provide the color to the lobster s exoskeleton.130132 Whereas most naturally occurring carotenoids have all-E double bonds, mono-Z isomers of canthaxanthin are found in the colored carotenopro-teins of the brine shrimp Artemesia.133... 

A radiation-induced signal can be detected in the exoskeleton of Norway lobster (Nephrops norvegicus) (Stewart etal., 1992) and other species of prawn and shrimp (Morehouse and Desrosiers, 1993). In the case of Norway lobster, the signal in both irradiated and unirradiated cuticle is complex because of the presence of the six resonance peaks due to Mn2+. In the irradiated samples there is an additional free radical peak in the centre of the Mn2+ signal at 349.5 mT (Figure 6). This signal is more easily seen when the... 

Chitin is a polysaccharide constituted of N -acctylglucosamine, which forms a hard, semitransparent biomaterial found throughout the natural world. Chitin is the main component of the exoskeletons of crabs, lobsters and shrimps. Chitin is also found also in insects (e.g. ants, beetles and butterflies), and cephalopods (e.g. squids and octopuses) and even in fungi. Nevertheless, the industrial source of chitin is mainly crustaceans. 

The Crustacea is the second largest group within the Arthropods. This diverse group includes lobsters, crabs, shrimp, sow bugs, barnacles, and many other forms. Over 38,000 species of Crustacea are known and there are probably many more yet to be discovered. Most Crustacea have a hard chitinous exoskeleton, three body segments, two pairs of antennae, and gills for breathing. Most... 

Chitin is isolated from the exoskeletons of crustaceans (e.g., crabs, lobsters, crayfish, shrimp, krill, barnacles), molluscs or invertebrate animals (e.g., squid, octopus, cuttlefish, nautilus, chitons, clams, oysters, scallops. 

The sand shrimp (Crangon septemspinosa) is the small cousin of the familiar, edible prawn, an inhabitant of deeper waters. Growing to only 2.5 inches (6.3 cm), this little shrimp is easy to identify because the front of its exoskeleton is shortened. The long-eyed shrimp (Ogyrides alphaerostris) is... 

Chitin is another highly available polysaccharide biopolymer it is derived from the exoskeleton of arthropods (specifically crab and shrimp shells) and formed from repeats of (l,4)-linked V-acetyl-p-D-glucosamine. In its natural form, the chains of... 

Chitosan is not widely present as such in nature and thus cannot be directly extracted from natural resources. Indeed, chitosan is a derivative of natural chitin, the second most abundant polysaccharide in nature after cellulose [2]. Typically, chitosan is obtained by deacetylation of the Ai-acetyl glucosamine units of chitin, generally by hydrolysis under alkali conditions at high temperature. The deacetylation of chitin is rarely complete. When the degree of acetylation falls below the value of 60 mol%, chitin becomes chitosan. In nature, chitin is present in life forms and more particularly in insects and crustaceans where it represents the major component of their exoskeleton. Chitin is also present in the cell wall of some mushrooms [7, 8]. Generally, chitosans produced from mushrooms present a narrow molecular weight distribution compared to chitosan produced from shrimps, and a non-animal source is considered to be safer for biomedical and healthcare uses. 

Chitin is a homopolymer of AT-acetyl-D-glucosamine residues and is a major structural component in the exoskeletons of crustaceans, mollusks, arthropods, and the cell walls of numerous fungi and algae. Owing to its widespread presence in both terrestrial and aquatic organisms, chitin is second only to cellulose as the most abundant biopolymer on the Earth (Shahidi and Abuzaytoun, 2005). On a dry weight basis, shrimp, crab, lobster, prawn, and crayfish have been reported to contain between 14% and 35% chitin, while deproteinized dry shell waste of Antarctic krill contains approximately 40% crude chitin (Haard et al, 1994). Crustaceans are the primary sources of chitin used in industry. Chitin can be extracted from shellfish and crustacean waste by mixing with a dilute add to induce demineralization, followed by a deproteini-zation step in a hot alkaline solution (Synowiecki and Al-Khateeb, 2003). 

It is a substance found naturally in the shells of crustaceans, such as crab, shrimp, and lobster. It is also found in the exoskeleton of marine zooplankton, such as coral and jellyfish. Insects also have chitin in their wings. Examples would be butterflies and ladybugs. The cell walls of mushroom and other fungi contain this also. This substance is used in food, cosmetics, and biomedicine. It has been found to be an antibacterial, antifungal, and antiviral and used for wound dressings, sutures, cataract surgery, and periodontal disease treatment. Its many sources and uses make it a fascinating material. 

---