Nathalie Berezina

Production and application of chitin

De Gruyter | Published online: September 30, 2016

1 Introduction

For some years now, biopolymers have attracted great interest from both academia and industry. Some of them have been investigated for a long time, such as rubbers [1], the interest in others, such as starch, cellulose [2] or PHA [3], is mainly being driven by ecology concerns. Chitin is somehow apart from this mainstreaming interest in biopolymers. Indeed, as the second major biopolymer worldwide after cellulose, it is mainly produced as a byproduct in shellfish industry. Therefore its production was less a concern for its valorization through different applications and subsequent purifications and derivatizations [4, 5].

Chitin is a polysaccharide, more precisely an aminoglucopyranan, composed of N-acetylated glucosamine (GlcNAc) and glucosamine (GlcN) units (Figure 1), linked by β(1,4) covalent bonds [6]. Due to this specific linkage, chitin exhibits an extremely robust structure towards chemical and biological aggression, indeed the β(1,4) chitin bond is similar to the one found in cellulose, contrary to starch, that is much more easily digested by enzymes of several (micro)organisms than cellulose and presents an α(1,4) covalent bond between its monomeric units.

Figure 1: Chemical structure of chitin.

Figure 1:

Chemical structure of chitin.

Moreover, the N-acetyl group attached to the major part of the glucosamine monomeric units of chitin confers to it extremely poor solubility properties, making chitin difficult to process and thus limiting its potential applications [4]. To circumvent this issue, the hydrolysis of the acetyl group, also called deacetylation, can be applied (Figure 2). When GlcN units are predominant compared to GlcNAc units, the biopolymer is no longer designated as chitin, but as chitosan. Therefore the degree of acetylation (DA) (or the degree of deacetylation (DD)) is used to characterize the chitin/chitosan biopolymers as well as their degree of polymerization or source.

In this chapter the origin, different natural sources, subsequent issues related to the extraction and the purification of chitin, as well as its properties and applications are discussed.

Figure 2: Deacetylation of chitin to chitosan.

Figure 2:

Deacetylation of chitin to chitosan.

2 Historical outline

Chitin was most probably discovered by an English scientist A. Hachett, who reported in 1799 “a material particularly resistant to usual chemicals”, but as he did not push his investigations any further, the discovery of chitin is usually attributed to a French naturalist from Nancy, Henri Braconnot [7], who identified this biopolymer in 1811 in extracts of mushrooms, and thus gave it the name of “fungine” [8]. A few years later, in 1823, Auguste Odier found the same biopolymer in the insect’s exoskeleton, and named it “chitin” in reference to a Greek “chiton” meaning “tunic” [9].

The interrogation on the difference between cellulose, produced by plants, and chitin produced by arthropods was initiated by Payen in 1843 [9]. In the same year Lassaigne found the presence of nitrogen in chitin, when working with the exoskeleton of silkworm butterfly, Bombix morii [9]. Then, Ledderhose identified glucosamine and acetic acid as structural units of chitin in 1879, and Gilson confirmed glucosamine to be the repeated unit of chitin in 1894 [9]. The final chemical nature of chitin was elucidated by Purchase and Braun in 1946 [9].

Chitosan was first obtained from chitin by C. Rouget [10], when boiling chitin in a concentrated alkali solution and noticing that the resulting compound was soluble in organic acids. Further, F. Hoppe-Seiler confirmed in 1894 that chitosan is the deacetylated form of chitin and thus gave it its actual name [10].

Another milestone in the discovery of chitin’s structure and arrangement was made by Bouligand. He discovered in 1965 that chitin adopts a stereotypic arrangement in arthropods [11]. Thus, three main types were found, α-, β- and γ-types (Figure 3). The α-type exhibits an antiparallel disposal of chitin molecules, thus strengthening the intra- and inter-molecular hydrogen bonds. The α-type is the most robust type of chitin, it is the most resistant toward physical and chemical aggression and is also the one mainly found in nature. In contrast, the β-type chitin arrangement characterizes parallel chains’ aggregation, in this case N -acetyl groups play the role of spacers, allowing easier access to molecules of water, for hydration purposes and subsequent gel formations [11]. Finally, the γ-type is mainly composed by 2 parallel and 1 antiparallel layers, its strength and resistance are closer to the β-type, the N -acetyl groups playing the same role in both those arrangements. In addition, non-crystalline, transient states have also been reported in a fungal system[12].

Figure 3: Different chitin structures according to Bouligand.

Figure 3:

Different chitin structures according to Bouligand.

Further, the macroscopic arrangement of chitin layers and protein scaffolds surrounding them on a cholesteric helix was studied [13], a twisted plywood structure was thus found in the lobster Homarus americanus [14] and in the sheep crab Loxorhynchus grandis [15], it has also been reported to be responsible for the iridescence of the scarab beetle [16].

3 Sources

Chitin is present in the exoskeleton of arthropods [17], also in eukaryotic cells, such as those of fungi [18] and mushrooms [19]. It is also found in the iridophores (reflective material) in the epidermis and the eyes of certain arthropods and cephalopods [20]. One study [20] has even reported that the epidermal cuticle of a vertebrate, a fish named Paralipophrys trigloides, contains chitin; thus suggesting that chitin can also be produced by vertebrates.

As chitin is present in so many different species, it would be, of course, very tempting to use chitin for evolution and taxonomy of these different species, however to the best of our knowledge those studies have still to be done. Also, a comparison between different properties, contents, etc. of chitin from different sources would be of great interest, but for now scientists could not distinguish any specific characteristics for chitin extracted from different sources (α-chitin being dominating in any shellfish, insects, etc.), also the content comparison faces the issue of chitin extraction and characterization, detailed below.

Despite this very large diversity of chitin sources, until now, mainly chitin from the shellfish industry has been explored. It was thus shown that crustaceans mainly produce α-chitin, whereas cephalopods produce β-chitin, also the chitin content varies from 7 to 36% in crustaceans and from 20 to 40% in cephalopods, howeverwe have to acknowledge that in this study for 10 species of crustaceans explored, only two representative of cephalopods were considered, therefore the conclusions concerning this latter class may be less accurate [21].

A few studies performed on insect chitin were mainly concerned with butterflies [22]. It was thus shown that the wings of the painted lady butterfly, Vanessa cardui Linnaeus, exhibits α-type chitin [22]. The insects exhibit a complex hierarchical structure, where each epidermal scale represents one color. These scales are morphologically homogeneous and adherent to the wings in rows, which run parallel to the anterior-posterior axis of the wing [22].

The chitin content is usually in the range of 5 to 40% of dry mass of cuticle, thus honeybees were reported to have organic matrices with 23–32% of chitin [17], mushrooms 8–16% [17] and shellfish 5–40% [21], and even up to 49% were reported in squid pens [23]. The chitin content within the same species during the lifetime of the organism seems to remain stable, it was found to be around 3% in Calanus helgolandicus [24].

Also, the determination of chitin content in its original source remains an issue. Indeed, no reliable analytic methods have been reported until now, infrared and diffraction analysis allowing only qualitative and non-quantitative approaches [25], therefore the only quantitative method mainly used upto now is the so called“alkaline extraction” method [25]. However, it strongly depends on the source and extraction procedure used, which may explain severe differences observed in the literature concerning some species, namely cuttlefish was found to have only 5.8% of chitin by Hajji et al. [26] and up to 20% by Rhazi et al. [21], whereas shrimp was found to have up to 37.2% chitin by Hajji et al. [26] and only 22% by Rhazi et al. [21].

4 Extraction and purification

As we have seen from the previous paragraph, the extraction and purification of chitin is not only important for the recovery of the desired product but also to characterize the chitin content in different sources. Up to now two main approaches for chitin extraction have been studied: chemical and biological approaches.

4.1 Chemical extraction

Chemical extraction basically consists of two steps: acidic treatment for mineral elimination and basic treatment for protein elimination [27, 28]. The classical procedure can consist of an acidic treatment with HCl 1 M for 2 to 24 hours, followed with a basic treatment with NaOH 1 M for another 24 to 48 hours. The temperature usually is kept at 60–90 °C to avoid as much as possible chitin degradation and preserve its structure. The different parameters of these treatments can be tuned in order to adapt to a specific source of chitin or to combine different steps [17, 29].

Thus, for example, the mineral content is especially high within shellfish sources of chitin whereas lipid content is much higher in insects. Therefore, the acidic treatment can be adjusted, especially through the solid-state approach, to combine the elimination of both these sources of contamination and to obtain highly crystalline chitosan [30].

Also the alkali concentration for the deproteination step is of specific interest, as at high temperature and concentration the reaction continues up to deacetylation and the obtained product is no longer chitin, but chitosan [31].

The utilization of acidic and basic conditions at high temperature may also damage the integrity of the chitin polymer, and oligosaccharides can be thus obtained. It can present advantages for some applications, shorter chains inducing better solubility, but also drawbacks of chain alteration [18].

Another issue consists of a very poor ability to analyze the obtained product, several attempts through infrared [32], diffraction [25], fluorescence [33] or NMR [21, 26] techniques were made, however they did not give sufficiently satisfying results [25, 28, 29], and only a combination of several of these approaches allows the confirmation of the structure and purity of the chitin.

Another aspect of the purification of chitin is its color. Indeed, melanins and other sclerotins [12, 17] attached to the exoskeleton of arthropods or other chitin sources make it difficult to obtain a pure white chitin at the end of the process, therefore bleaching agents, such as hydrogen peroxide, are often used to finalize the chitin purification [34]. Other techniques, such as γ-radiation, were also tested to improve the extraction of chitin [35].

The main drawback of the utilization of chemical extraction remains however its energetic and environmental impact due to the extensive utilization of acidic and basic solutions requiring further neutralization and elimination [34].

4.2 Biological extraction

The biological methods for the extraction of chitin have been developed recently [34]. They can use either purified enzymes [36, 37] or whole microorganisms [38].

Although more environment friendly, these methods remain less efficient, one of the main reasons being the up to now poor understanding of the main covalent links between chitin and the surrounding proteins and melanins [12, 17]. Indeed, the main enzymes used for the purification of chitins are proteases, they cut protein bonds to give peptides and amino acids, however they cannot liberate chitin from catechols or even amino acids directly attached to it.

In this case, it becomes even more difficult to avoid bleaching steps, thus reducing the scope of pure biological extraction and making it much more biochemical [34].

As neither chemical nor biological methods are completely satisfying for now, several academic teams and industrial companies are still working on their improvements. This extraction stage is, indeed, essential for chitin and chitosan to fulfill the huge potential those molecules can present.

5 Applications

Chitin and chitosan have recently been reported to present several properties such as biocompatibility [39], biodegradation [40], scavenging of heavy metal [41] and of cholesterol or other fats [42], antimicrobial and antioxidative behaviors [43, 44], etc. However, we have to acknowledge that even if those biopolymers seem very promising, until now, the actual applications remain rather limited.

This can be explained by different aspects: the difficulty of extraction and purification of the original chitin, the necessary transformation of chitin to chitosan followed by the derivatization of the latter for most of applications [4547], etc.

Also, some of the previously mentioned assertions appeared less obvious that they seemed at first glance, for example, it would be difficult for the same molecule to present antimicrobial and biodegradation properties, actually if the antimicrobial aspect of chitin and chitosan seems to be proven, their biodegradation appears much more doubtful [48]. Similarly, the fact that chitin is difficult to purify, namely from fats, does not necessarily mean that it makes it good candidate for lowering cholesterol in blood.

For all the reasons mentioned above, we will focus our attention in this chapter mainly on biomedical, agricultural, materials and water purification applications of chitin and chitosan.

5.1 Biomedical applications

The main biomedical applications of chitosan are in wound healing. This application combines two of the most interesting properties of chitosan: antimicrobial behavior and biocompatibility [4]. These products have been on the market since the early 1990s, mainly in Asia and North America, but also in Europe, however to a lesser extent.

These products are commercialized by companies such as BioSyntech (Canada), Hemcon (USA), Medovent (Germany), Marine Polymers Technologies (USA), Cytosial (France).

Some other biomedical applications of chitosan were also studied, such as bone substitutes [4, 49], blood interactions [4, 50], drugs vectorization [4], implants [51], or anti-inflammatory [52, 53], antihypertensive [54] and anticancer [55] drugs; however most of these applications have not yet reached the actual market of biomedical products.

Finally, chitosan was also shown to be active against cryptosporidiosis in goats, significantly reducing the excretion of oocysts of C. parvum and diarrhea, and enhancing the weight gain of young animals [56].

5.2 Agricultural applications

Chitin and chitosan were reported to contribute to the protection of plants against pathogens. However, in this application, chitin and chitosan were described to play very different roles.

Chitin was reported to contribute to the protection of seeds, mainly by allowing the growth of microbial pesticides, such as Trichoderma harzianum P1, which was reported to be active against foliar disease. The addition of chitin to the medium specifically contributed to the growth of T. harzianum and partially inhibited the growth of certain pathogens such as R. solani, thus playing a double role: enhancing the production of suitable microorganisms and lowering the invasion of unsuitable ones through actual inhibition and further demographic control [57].

Chitosan was described to act as an elicitor, indeed, several plants possess chitinolytic enzymes, which help them to defend themselves against pathogen aggressors, such as fungi. The introduction of chitosan in the growth medium stimulates the production of chitinolytic enzymes in plants, thus making them more resistant towards their natural aggressors [58, 59].

5.3 Materials applications

For a long time chitosan as a material was used as a plastic for the production of antimicrobial films for the food industry, i.e. packaging protecting fresh vegetables, fruits or meat [60].

Several attempts to produce novel biofunctional materials were also made, such as grafting of ester derivatives of poly(ethylene glycol) (PEG) [61] or phosphomethylation [62, 63].

More recently, some novel applications received greater interest, among them the utilization of chitosan as a catalyst support is of particular interest. Indeed, this application combines several up-to-date techniques, such as freeze drying [64] or utilization of supercritical CO2 (scCO2) [65] to increase the surface exchange capabilities and/ or utilization of ionic liquids [66, 67]. It thus contributes to the implementation of green chemistry principles by minimizing the amount of required product – catalytic and not stoichiometric proportions, and utilization of renewable raw materials – second most abundant biopolymer worldwide.

5.4 Water purification

The quality of water remains one of the huge issues humanity is currently facing. Access to pure water in some parts of the world remains difficult, thus generating malnutrition, diseases, and even military conflicts. Therefore the purification of water that was initially unsuitable for use or polluted is of crucial importance. To contribute to the wellbeing of a larger population the chosen water treatment techniques have to be technically and economically efficient.

Different techniques are usually applied to water purification, such as scavenging, adsorption, flocculation or biological treatments. Chitosan can be applied for adsorption [68, 69] and flocculation [70] purposes, the fact that it is an environment friendly compound, very abundant and rather cheap makes it a solution of choice in certain cases. Thus chitosan was shown to be particularly efficient for the flocculation of cardboard-mill secondary biological wastewater [70], unfortunately the actual applications in industry remain rather rare, as concurrent flocculating agents are cheaper. Indeed, even if chitosan shows better properties, the traditional cheaper products are sufficient to fulfill current regulatory frameworks.

6 Outlook

Chitin is a second most abundant biopolymer on Earth after cellulose. Present in several species, it is, until now, mainly obtained from the discards of the shellfish industry. Its extraction and purification as well as the reliability of available sources remain an issue and unfortunately impacts its widespread applications. Also, as chitin has a rather poor range of applications that can be exploited, mainly focused on the agricultural area, it has to be transformed by deacetylation to chitosan, and sometimes even further by derivatization of the latter.

Despite extremely interesting properties, such as biocompatibility or antimicrobial behavior, the applications of chitosan in the biomedical area remain limited, mainly due to the extreme difficulty to access sufficient purity and source reliability of the biopolymer. The materials applications until now are rather limited, mainly due to the cost of the product, which remains higher than that of petroleum based polymers with similar properties. The applications in the agricultural fields seem very promising but require more research and development to achieve significant results, therefore the main utilization of chitosan is now the purification of water, achieved by scavenging of heavy metal residues.

Finally, for the widespread utilization of these truly very promising biopolymers, beside strong scientific developments, intellectual rigor is also mandatory, to promote only actual properties and to avoid attributing fashionable but not proven ones.


This article is also available in: Luque/Xu, Biomaterials. De Gruyter (2016), isbn 978–3–11–034230–7.


[1] Martelli SM, Lin CSK, Sun Z, Berezina N, Fakhouri FM,-Mei LHI. Natural rubber blends with biopolymers, in Natural Rubber Materials: Volume 1: Blends and IPNs, RSC, 2013, 1, 370–93. Search in Google Scholar

[2] Berezina N, Martelli SM. Bio-based polymers and materials In: Renewable resources for biore-fineries, RSC Green Chemistry 2014, 27, 1–28. Search in Google Scholar

[3] Berezina N, Martelli SM. Polyhydroxyalkanoates: structure, properties and sources. In: Polyhy-droxyalkanoate (PHA) based blends, composites and nanocomposites, RSC Green Chemistry 2015, 30, 18–46. Search in Google Scholar

[4] Khor H, Wan ACA. Chitin: fulfilling a biomaterials promise. Elsevier Insights, 2nd Ed., 2014. Search in Google Scholar

[5] Archer M, Russel D. Crustacea processing waste management. Seafish, 2008, 1–23. Search in Google Scholar

[6] Rebecca LJ, Susithra G, Sharmila S, Singh A. Optimization of physical parameters for chitinase production from Serratia marcescens, Res J PharmBiol ChemSci, 2013, 4, 1676–82. Search in Google Scholar

[7] Wisniak J, Henri Braconnot. Revista CENIC. Ciencias Químicas, 2007, 38, 345–55 and references cited therein. Search in Google Scholar

[8] Khoushab F, Yamabhai M. Chitin research revisited.Mar Drugs, 2010, 8, 1988–2012 and refer-ences cited therein. Search in Google Scholar

[9] Discover polysaccharides: chitins and chitosans. [last accessed 2nd July 2015], and references cited therein. Search in Google Scholar

[10] Teng D. From chitin to chitosan, in Chitosan-based hydrogels, Taylor & Francis Group, 2012, pp. 1–33 and references cited therein. Search in Google Scholar

[11] Thomas S, Durand D, Chassenieux C, Jyotishkumar P, Handbook of biopolymer-based materi-als: from blends and composites to gels and complex networks, John Wiley & Sons, 2013. Search in Google Scholar

[12] Merzendorfer H, Zimoch L. Chitin metabolism in insects: structure function and regulation of chitin synthases and chitinases, J. Exp. Biol., 2003, 206, 4393–412. Search in Google Scholar

[13] Charvolin J, Sadoc JF. About collagen, a tribute to Yves Bouligand, Interface focus, 2012, 1–8. Search in Google Scholar

[14] Raabe D, Romano P, Sachs C, Al-Sawalmih A, Brokmeier HG, Yi SB, Servos G, Hartwig HG. Discovery of a honeycomb structure in the twisted plywood patterns of fibrous biological nanocomposite tissue, J Crist Growth, 2005, 283, 1–7. Search in Google Scholar

[15] Chen PY, Lin AYM, McKittrick J, Meyers MA. Structure and mechanical properties of crab ex-oskeletons, Acta Biomaerialia, 2008, 4, 587–96. Search in Google Scholar

[16] Sharma V, Crneb M, Park JO, Srinivasarao J. Bouligand structures underlie circularly polarized iridescence ofscarab beetles: a closer view, Materials Today: Proc., 2014, 161–71. Search in Google Scholar

[17] Nwe N, Furuike T, Tamura H. Chitin and chitosan from terrestrial organisms, in Chitin, chitosan, oligosaccharides and their derivatives, CRC Press, 2010, pp. 3–10. Search in Google Scholar

[18] Rinaudo M. Chitin and chitosan: Properties and applications, Prog. Polym. Sci., 2006, 31, 603–32. Search in Google Scholar

[19] Kurtzman RHJr. Mushrooms: sources for modern western medicine, Micalogia Aplicada Int., 2005, 17, 21–33. Search in Google Scholar

[20] Khousab F, Yamabhai M. Chitin research revisited, Mar. Drugs, 2010, 8, 1988–2012. Search in Google Scholar

[21] Rhazi M, Desbrieres J. Investigation of different natural sources of chitin: influence of the source and deacetylation process on the physicochemical characteristics of chitosan, Polymer Int., 2000, 49, 337–344. Search in Google Scholar

[22] Schiffman JD, Schauer CL. Solid state characterization of α-chitin from Vanessa cardui Lin-naeus wings, Mat. Sci. Eng. C, 2009, 29, 1370–4. Search in Google Scholar

[23] Abdou ES, Nagy KSA, Elsabee MZ. Extraction and characterization of chitin and chitosan from local sources, Bioresour. Technol., 2008, 99, 1359–67. Search in Google Scholar

[24] Gervasi O, Jeuniaux C, Dauby P. Production de chitine par les crustacés du zooplancton de la baie de Calvie (Corse), IFREMER: Actes de colloques, 1988, 8, 33–8 in French. Search in Google Scholar

[25] Jeuniaux C, Voss-Foucart MF, Bussers JC. La production de chitine par les crustacés dans les écosystèmes marins, Aquat.Living Resour., 1993, 6, 331–41 in French. Search in Google Scholar

[26] Hajji S, Younes I, Ghorbel-Bellaaj O, Hajj R, Rinaudo M, Nasri M, Jellouli K. Structural differ-ences between chitin and chitosan extracted from three different marine sources, Int. J. Biol. Macromol., 2014, 65, 298–306. Search in Google Scholar

[27] Shahidi F, Synowiecki J. Isolation and characterization of nutrients and value-added prod-ucts from snow crab (Chinoecetes opilio) and shrimp (Pandalus borealis) processing discards, J. Agric. Food Chem., 1991, 39, 1527–32. Search in Google Scholar

[28] Rodde RH, Einbu A, Varum KM. Aseasonal study of the chemical composition and chitin quality of shrimp shells obtained from northern shrimp (Pandalus borealis), Carbohydr. Polym., 2008, 71, 388–93. Search in Google Scholar

[29] Lavall R, Assis OBG, Campana-Filho SP. Bioresour. Technol., 2007, 98, 2465–72. Search in Google Scholar

[30] Osorio-Madrazo A, David L, Trombotto S, Lucas JM, Peniche-Covas C, Domard A. Carbohydr. Polym., 2011, 83, 1730–9. Search in Google Scholar

[31] Plassard C, Mousan D, Salsac L. Dosage de la chitine sur des ectomycorhizes de pin maritime (Pinus pinaster) à Pisolithus tinctorius: évaluation de la masse mycélienne et de la mycorhiza-tion, Can. J. Bot., 1983, 61, 692–9. Search in Google Scholar

[32] Brugnerotto J, Lizardi J, Goycoole FM, Arguelles-Monal W, Desbrieres J, Rinaudo M. An in-frared investigation in relation with chitin and chitosan characterization, Polymer, 2001, 42, 3569–80. Search in Google Scholar

[33] Rabasovic MD, Pantelic DV, Jelenkovic BM, Curcic SB, Rabasovic MS, Vrbica MD, Lazovic VM, Curcic NPM, Krmpot AJ. Nonlinear microscopy of chitin and chitinous structures: a case study of two cave-dwelling insects, J. Biomed. Optics, 2015, 20, 016010–10. Search in Google Scholar

[34] Vázquez JA, Rodríguez-Amado I, Montemayor MI, Fraguas J, del Pilar González M, Anxo Murado M. Chondroitin sulfate, hyaluronic acid and chitin/chitosan production using marine waste sources: Characteristics, applications and eco-friendly processes: A review, Mar. Drugs, 2013, 11, 747–74. Search in Google Scholar

[35] Mahlous M, Tahtat D, Benamer S, Nacer Khodja A. Gamma irradiation-aided chitin/chitosan extraction from prawn shells, Nucl. Instr. Meth. Phys. Res. B, 2007, 265, 414–7. Search in Google Scholar

[36] Duarte de Holanda H, Netto FM. Recovery of components from shrimp (Xiphopenaeus kroyeri) processing waste by enzymatic hydrolysis, J Food Sci., 2006, 71, 298–303. Search in Google Scholar

[37] Synowiecki J, Al-Khateeb NAAQ, The recovery of protein hydrolysate during enzymatic isolation of chitin from shrimp Crangon crangon processing discards, Food Chem., 2000, 68, 147–52. Search in Google Scholar

[38] Xu Y, Gallert C, Winter J. Chitin purification from shrimp wastes by microbial deproteination and decalcification, Environ. Biotechnol., 2008, 79, 687–97. Search in Google Scholar

[39] Zhu A, Shen J. Biocativities of chitosan and its derivatives, in Chitosan-based hydrogels, Taylor & Francis, 2012, pp. 109–73. Search in Google Scholar

[40] Kumar MNVR. A review of chitin and chitosan applications, React. Funct. Polym., 2000, 46, 1–27. Search in Google Scholar

[41] Shepherd R, Reader S, Falshaw A. Chitosan functional properties, Glyconjug. J., 1997, 14, 535–42. Search in Google Scholar

[42] Koide SS. Chitin-chitosan: properties, benefits and risks, Nutr. Res., 1998, 18, 1091–101. Search in Google Scholar

[43] Kim KW, Thomas RL. Antioxidative activity of chitosans with varying molecular weights, Food Chem., 2007, 101, 308–13. Search in Google Scholar

[44] Park PJ, Koppula S, Kim SK. Antioxidative activity of chitosan, chitooligosaccharides and their derivatives, in Chitin, chitosan, oligosaccharides and their derivatives, CRC Press, 2010, pp. 241–50. Search in Google Scholar

[45] Mourya VK, Inambar NN. Chitosan-modifications and applications: opportunities galore, Reac-tive Funct. Polym., 2008, 68, 1013–51. Search in Google Scholar

[46] Tolaimate A, Desbrieres J, Rhazi M, Alagui A. Contribution to the preparation of chitins and chitosans with controlled physico-chemical properties, Polymer, 2003, 44, 7939–52. Search in Google Scholar

[47] Lai WF, Lin MCM. Chemical derivatization of chitosan for plasmid DNA delivery: present and future, in Chitin, chitosan, oligosaccharides and their derivatives, CRC Press, 2010, pp. 69–94. Search in Google Scholar

[48] Kirchman DL, White J. Hydrolysis and mineralization of chitin in the Delaware Estuary, Aquat. Microb. Ecol., 1999, 18, 187–96. Search in Google Scholar

[49] Muzzarelli RAA. Chitosan scaffolds for bone regeneration, in Chitin, chitosan, oligosaccharides and their derivatives, CRC Press, 2010, pp. 223–39. Search in Google Scholar

[50] Kim SK, Jung WK. Effects of chitin, chitosan and their derivatives on human hemostasis, in Chitin, chitosan, oligosaccharides and their derivatives, CRC Press, 2010, pp. 251–62. Search in Google Scholar

[51] Khor E, Lim LY. Implantable applications of chitin and chitosan, Biomaterials, 2003, 24, 2339–49. Search in Google Scholar

[52] Kim MM, Kim SK. Anti-inflammatory activity of chitin, chitosan, and their derivatives, in Chitin, chitosan, oligosaccharides and their derivatives, CRC Press, 2010, pp. 215–21. Search in Google Scholar

[53] Kim K, Ji HS. Effect of chitin sources on production of chitinase and chitosanase by Strepto-myces griseus HUT 6037, Biotechnol. Bioprocess Eng., 2001, 6, 18–24. Search in Google Scholar

[54] Je JY, Ahn CB. Antihypertensive actions of chitosan and its derivatives, in Chitin, chitosan, oligosaccharides and their derivatives, CRC Press, 2010, pp. 263–70. Search in Google Scholar

[55] Ta HT, Dunstan DE, Dass CR. Anticancer activity and therapeutic applications of chitosan nanoparticles, in Chitin, chitosan, oligosaccharides and their derivatives, CRC Press, 2010, pp. 271–84. Search in Google Scholar

[56] Adjou K, Mammeri M, Grasset-Chevillot A, Marden JP, Auclair E, Mage C, Vallée I. Maitrise de la cryptosporidiose avec le chitosan: essi in vivo. Proceedings: Journées nationales DTV – Nantes 2015, pp. 377–80 in French. Search in Google Scholar

[57] Tronsmo A, Skaugrud O, Harman GE. Use of chitin and chitosan in biological control of plant diseases, in Chitin enzymology, Eur. Chitin Soc., 1993, pp. 265–70. Search in Google Scholar

[58] Kato J, Shimura Y, Sogitani M, Torii H, Nakajima K, Oishi K. Physiological role of chitinase and chitin-binding lectin in cucumber,in Chitin enzymology, Eur. Chitin Soc., 1993, pp. 257–64. Search in Google Scholar

[59] Lienart Y, Gautier C, Dubois-Dauphin R, Domard A. Tetramers of chitin (chitosan) as elicitors in Rubus protoplasts, in Chitin enzymology, Eur. Chitin Soc., 1993, pp. 271–6. Search in Google Scholar

[60] Nadarajah K, Prinyawtwatkui W, No HK, Sathivel S, Xu Z. Sorption behavior of crawfish chi-tosan films as affected by chitosan extraction processes and solvent types, J Food Sci., 2006, 71, 33–39. Search in Google Scholar

[61] Leduc F, Dez I, Desbrieres J, Picton L, Madec JP. Different ways for grafting ester derivatives of poly(ethylene glycol) onto chitosan: related characteristics and potential properties, Polymer, 2005, 46, 639–51. Search in Google Scholar

[62] Leduc F, Dez I, Madec JP. NMR study of the phosphonomethylation reaction on chitosan, Polymer, 2005, 46, 319–25. Search in Google Scholar

[63] Leduc F, Dez I, Gulea M, Madec JP, Jaffres PA. Synthesis of phosphorus-containing chitosan derivatives,in Phosphorus, sulfur, and silicon, Taylor & Francis, 2009, pp. 872–89. Search in Google Scholar

[64] Jouanin C, Vincent C, Dez I, Gaumont AC, Vincent T, Guibal E. Highly porous catalytic ma-terials with Pd and ionic liquid supported on chitosan, J. Appl. Polym. Sci., 2013, DOI: 10.1002/app.38501. Search in Google Scholar

[65] Moucel R, Perrigaud K, Goupil JM, Madec PJ, Marinel S, Guibal E, Gaumont AC, Dez I. Impor-tance of the conditioning of the chitosan support in a catalyst-containing ionic liquid phase immobilized on chitosan: the palladium-catalysed allylation reaction case, Adv. Synth. Catal., 2010, 352, 433–39. Search in Google Scholar

[66] Clousier N, Moucel R, Naik P, Madec PJ, Gaumont AC, Dez I. Catalytic materials based on cat-alyst containing ionic liquid phase supported on chitosan or alginate: importance of the support, C. R. Chimie, 2011, 14, 680–4. Search in Google Scholar

[67] Baudoux J, Perrigaud K, Madec PJ, Gaumont AC, Dez I. Developmetn of new SILP catalysts using chitosan as support, Green Chem., 2007, 9, 1346–51. Search in Google Scholar

[68] Crini G. Recent developments in polysaccharide-based materials used as adsorbents in wastewater treatment, Prog. Polym. Sci., 2005, 30, 38–70. Search in Google Scholar

[69] Crini G. Non-conventional low-cost adsorbents for dye removal: A review, K, 2005, DOI: 10.1016/j.biotech.2005.05.001. Search in Google Scholar

[70] Renault F, Sancey B, Charles J, Morin-Crini N, Badot PM, Winterton P, Crini G. Chitosan floccula-tion of cardboard-mill secondary biological wastewater, Chem. Eng. J., 2009, 155, 775–83. Search in Google Scholar

Published Online: 2016-9-30
Published in Print: 2016-9-30

© 2016 by Walter de Gruyter Berlin/Boston