10. Conclusion

The calculation of DD and the number of amine present in chitosan by FTIR allows first to follow the transformation reaction of chitin into chitosan and others by finding the optimal conditions for the synthesis of chitosan by studying the effect of different parameters, namely the concentration of the base, the temperature, and the duration of the reaction. The valorization of shrimp exoskeletons by extraction of chitosan according to the hydrothermal-chemical technique proposed in two stages makes it possible to reduce the production time by at least four times compared to the conventional technique in three stages (3–4 days). In addition, the consumption of digestion and energy chemicals is also significantly reduced. The chitosan obtained by the two-step technique is of good quality. Indeed, the degree

of deacetylation is greater than 90% under the optimal conditions for the simultaneous deproteinization and deacetylation.

References

[1] Okazaki S, Tachibana T, Naganuma A, Mano N, Kuge S. Multistep disulfide bond formation in Yap1 is required for sensing and transduction of H2O2 stress signal. Molecular Cell. 2007;27(4):675-688

IntechOpen; 2018. p. 75208

Echetna M, Naciri Bennani M,

2013;2(3):503-513

151-209

2014

125

[2] Boukhlifi F, Mamouni FZ, Razouk R. Chitin/Chitosan's bio-fertilizer: Ch 16: Usage in vegetative growth of wheat a nd potato crops. In: Dongre RS, editor. Chitin-Chitosan – Myriad Functionalitie s in Science and Technology. Rijeka:

DOI: http://dx.doi.org/10.5772/intechopen.89708

Quantitative Analysis by IR: Determination of Chitin/Chitosan DD

[8] Ngo DN, Kim SK. Antioxidant, antimicrobial properties of chitin, chitosan, and their derivatives. Advances in Food and Nutrition

[9] Boukhlifi F, Bencheikh A. Study of the competitive adsorption of heavy metals on crude chitin: Application to wastewater from a chemical industry. The Water Tribune. 2001;55(611/3):

Characterization of natural biosorbents used for the depollution of waste water.

[11] Boukhlifi F. Study of the retention of metallic micro-pollutants (Pb, Cd, Cu and Zn) on new biosorbent materials: liquid industrial effluent purification tests [doctoral thesis]. Morocco: Chouaib Doukkali El University jadida;

[12] Boukhlifi F, El Akili C, Moussout H, Benzakour A, Ahlafi H. Treatment of global rejection of electroplating industry by raw chitin. International Journal of Applied Environmental

[13] Boukhlifi F, Bencheikh A, Ahlafi H. Characterization and adsorption of chitin toward copper Cu2+. Physical and

Chemical News. 2011;58:67-72

of ionic-strength and degree of acetylation on chain expansion. International Journal of Biological Macromolecules. 1993;15(5):281-285

[14] Rinaudo M, Milas M, Ledung P. Characterization of chitosan—Influence

[15] Wei W, Bo SQ, Li SQ, Wen Q. Determination of the mark–Houwink equation for chitosans with different degrees of desacetylation. International

Sciences. 2013;8:13-23

[10] Boukhlifi F, Bencheikh A.

Annales de Chimie Science des Materiaux. 2000;256:153-160

Research. 2014;73:15-31

37-43

2000

[3] Ahlafi H, Moussout H, Boukhlifi F,

Slimane SM. Kinetics of N-deacetylation of chitin extracted from shrimp shells collected from coastal area of Morocco. Mediterranean Journal of Chemistry.

[4] Ouattara B, Simard RE, Piette G, Begin A, Holley RA. Inhibition of surface spoilage bacteria in processed meats by application of antimicrobial

films prepared with chitosan. International Journal of Food Microbiology. 2000;62:139-148

[5] Muzzarelli RAA, Muzzarelli C. Chitosan chemistry: Relevance to the biomedical sciences. Advances in Polymer Science Journal. 2005;186:

[6] Alves MN, Mano JF. Chitosan derivatives obtained by chemical modifications for biomedical and environmental applications. International Journal of Biological Macromolecules. 2008;43:401-414

[7] Dzung NA. Chitosan and chitosan derivatives as potential adjuvants for influenza vaccine. In: Kim SK, editor. Chitin and Chitosan Derivatives: Advances in Drug and Discovery and Developments. CRC Taylors & Francis;

The compression method for preparing 100% deacetylated chitosan with less environmental pollution was studied by FTIR. The 100% fully deacetylated chitosan was produced in low-concentration alkali and high-pressure conditions, which only requires 15% alkali solution and 1:10 chitosan powder to NaOH solution ratio under 0.11–0.12 MPa for 120 min. When the alkali concentration varied from 5–15%, the chitosan with ultra-high DD value (up to 95%) is produced.

In parallel, the FTIR calculation was also used to show that the microwave could be used in the extraction step of chitosan from chitin. From these results, it could be concluded that shrimp waste is an excellent source for chitin, and the yields of chitosan increased with decreasing the chitin particle size and increasing the concentration of NaOH solution used in deacetylation step. The highest degree of deacetylation was obtained from chitin samples at particle size of 60 mesh deacetylated by 50% NaOH solution, and it was 95.19% compared with 85% for commercial chitosan. Based on this synthesis, it is concluded that FTIR is an effective and reliable technique for the determination of DD and the study of the deacetylation reaction of chitin. All the formulas quoted are valid for calculating DD of chitosan, but the most reliable formula and the formula most approved by other techniques is formula 3 quoted in our works.
