Commercial chitin, derivation

In conclusion, it is noteworthy that cyclodextrins, liposomes and chitin derivatives are all readily available from renewable biochemical sources and offer advantages of biodegradability and safety in use. However, it needs to be borne in mind that this fact alone does not necessarily mean that they are entirely environmentally innocuous in the long run. Demands on resources for the husbanding and processing of bioforms that may be necessary in order to sustain demand for commercially viable qualities and quantities can exert deleterious effects, not least because they may give by-products that present problems of utilisation or disposal [70]. 

Commercial chitin is mainly derived from waste products of... 

Water soluble chitin 50 and chitosan were developed from the chitin and has been used as exogenous elicitors for the production of chitinases and anthraquinone in Morinda citrifolia thorugh cell culture. On the other hand, the commercial pectin derived from M. citrifolia, it can be induced chitinase and lysosome activities (Heike and Dietrich 1994). 

Chitin and its derivatives are natural, nontoxic, biodegradable polymers with a broad range of commercial properties and applications. Although these biopolymers can be used in various industrial fields, this chapterfocuses on the use of chitin derivatives in the functional foods and dietary supplement industries. Many studies have reported the im-muno-modulatory effects in the form of antibacterial, anti-inflammatory, antioxidant, anticarcinogenic, or antiulcer activity [186-188] and found that chitosan derivatives are nonallergenic, so the body is not... 

Chitosan is a polymer with metal-binding properties that is derived from naturally occurring chitin. Research has been conducted on the potential use of chitosan in hazardous waste remediation. While chitosan does bind transition metals, it favors iron, a nonhazardous metal, which competes and interferes with chitosan s binding of toxic metals. Copper also tends to be highly bound, while the amount of cadmium and lead removed is lower. The technology is still undergoing testing and is not yet commercially available. 

Like cellulose, the primary biological function of chitin is for structural support. And like cellulose, it is quite insoluble. Strong acids hydrolyze the amide to give the protonated amine, which is soluble at low pH. Given its abundance in nature, there has always been interest in finding commercial application for chitin or its derivatives. So far these efforts have achieved only limited success. 

The rigidity of a crab shell is due to chitin, a high molecular weight carbohydrate molecule. Chitin-based coatings have found several commercial applications, such as extending the shelf life of fruits. Processing plants now convert the shells of crabs, lobsters, and shrimp to chitin and various derivatives for use in many consumer products. 

An interesting application of derivative sp>ectrophotometiy was described by Wu and Zivanovic [46], They proposed the use of the first derivative spectra for determination of the degree of acetylation of chitin and chitosan. They employed the evaluated procedure for commercial samples. 

Up to now, eleven BPUs have been commercialized or are on late-stage development as chitin synthesis inhibitors that contain both fluorine (2-9) and chlorine (1-3) atoms. Early studies on structure-activity relationships (SAR) of BPUs reflected little scope for variation of substituents at the N-benzoyl moiety. Only derivatives with at least one ortho substituent retained insecticidal activity. Such an ortho-substituent (R ) can be methyl, OCF3, or OC2F5 and lead to active derivatives. However, all commercialized products have ortho-halogen substituents and the insecticidal or acaricidal activity generally follows in the order (Hal, Ri) 2,6-F2 > 2-Cl, 6H > 2,6-Cl2 > 2-F, 6H (Fig. 35.10, Table 35.7). 

Chitosan is a natural polysaccharide that has been widely explored for the delivery of nucleic acids. The compound is derived via deacetylation of chitin yielding repeated glucosamine and N-acetyl glucosamine units bonded via p(l—>4) glycosidic bonds (see Figure 2(d)). Chitosan is widely studied because this biopolymer is commercially available, low in cost, biodegradable, and contains functional groups (primary and secondary hydroxyls and primary amines) that can... 

Chitin, chitosan, and their derivatives have been applied for wound treatment in the veterinary field since 1988, and one of the first cases of chitosan application was reported on a case of canker in a draft horse (Minami et al. 1991). They have also summarized clinical cases using chitin and chitosan to large animals (cows and horses) (Minami et al. 1992), small animals (dogs and cats) (Okamoto et al. 1992), and zoo animals (mammals, reptiles, and birds) (Fukumoto et al. 1995) using the chitin products (Chitipack S and Chitipack P), and a chitosan product (Chitopack C), which are commercialized in Japan. In comparison with conventional therapy with irrigation and antibiotic administration to a wound, new treatments with chitin and chitosan products permitted a substantial decrease in treatment frequency with minimal scar formation. 

Environmental requirements are assuming great importance, since there is an increased interest in the industrial use of renewable resources such as starch and chitin. Considerable efforts are now being made in the research and development of polysaccharide derivatives as the basic materials for new applications. In particular, the increasing cost of conventional adsorbents undoubtedly makes chitin and chitosan-based materials one of the most attractive biosorbent for wastewater treatment. Chitin and chitosan biopolymers have demonstrated outstanding removal capabilities for certain pollutants such as dyes and metal ions as compared to other low-cost sorbents and commercial-activated carbons. Biopolymer adsorbents are efficient and can be used for the decontamination of effluents (removal of pollutants) and for separation processes (recovery of valuable metals). 

Keeping in mind the importance of chitosan, as well as its economic value as an industrial product, we must pay attention to its key physical parameter, i.e., turbidity. Depending on source, a marked difference is observed in aqueous solutions of chitosan and its derivatives in terms of their turbidity [33]. Turbid aqueous solutions of chitosan and chitosan-derived products greatly lose their commercial value. Such chitosan cannot be used as a commercial product and in some cases may have to be discarded. Therefore, the selection of source plays a pivotal role in the production of chitin and chitosan. Shepherd et al. [20] reported the production of chitosan from New Zealand Arrow squid Notodarus sloani) pens as well as the evaluation of the functional properties of this squid chitosan compared with chitosan extracted from crustacean sources. Squid pen chitin and chitosan were visibly cleaner than chitin and chitosan obtained from crab and crayfish. In addition, due to the lower mineral content of squid pen as compared to cmstacean shells, the demineralization process can be skipped to extract chitin, which also makes the production cheaper. As shown in Table 4, the squid pen chitosan is similar in... 

Chitin is a long-chain polymer of Ai-acetylglucosamine, a derivative of glucose, and normally found in the shells of crabs, lobsters, shrimps, and insects (Fig. 1.11). Chitosan is the partially deacetylated form of chitin and the degree of deacetylation can vary from 60% to 100% in commercial chitosans (Rinaudo, 2006) (Fig. 1.12). 

Chitosan fungi wall membrane (Mucor rouxil), commercially derived from chitin by chemical conversion with strong alkali 2-amino-2-deoxy-D-glucosc (D-N-glucosamine) in /I (1-4) linkage, cationic... 

Synthetically Modified Polysaccharides. Water solubility can be conferred on a number of naturally occurring polysaccharides by synthetic derivations producing charged or polar functionality. Two of nature s most abimdant polysaccharides, cellulose and chitin, have been synthetically modified in a multitude of ways to produce polymers with significant commercial utilization (86,87). 

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