Tenebrio Molitor breeding rejects as a high source of pure chitin and chitosan: Role of the processes, influence of the life cycle stages and comparison with Hermetia illucens

• Published in: International journal of biological macromolecules Vol. 277; no. Pt 3; p. 134475
• Main Authors: Azzi, M., Elkadaoui, S., Zim, J., Desbrieres, J., El Hachimi, Y., Tolaimate, A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-10-2024; Elsevier
• Subjects: Analytical chemistry; Biopolymers; Chemical Sciences; Chitin; Degree of acetylation (DA); Exuviae; Material chemistry; Molar mass (Mv); or physical chemistry; Polymers; Tenebrio molitor; Theoretical and; Exuviae; Chitin; Degree of acetylation (DA); Molar mass (Mv); Tenebrio molitor; Biopolymers; Tenebrio molitor Exuviae Chitin Biopolymers Degree
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.134475

This work valorizes rejects from Tenebrio Molitor TM breeding through the production of chitin and chitosan. Two processes are proposed for extracting chitin from larval exuviae and adult. The first process P1 provides chitin with high contents compared to literature data but the characterization shows the presence of impurities in the exuviae chitin responsible for the shifts in the values of the physicochemical characteristics towards those presented by γ chitin. These impurities are removed by delipidation and pure α chitin is obtained. The effective delipidation of this chitin would be linked to its fibrous surface structure. The analysis of the results of P1 led us to develop a second extraction process P2 which provides pure chitin with improved yields using delipidation followed by deproteinization. The N-deacetylation of chitin according to Kurita or Broussignac process makes possible the preparation of pure, highly deacetylated chitosan samples (2 % < DA < 12 %) with high yields and controlled molar masses (Mv). A kinetic study of molecular degradation during deacetylation is carried out. A comparison with Hermetia illucens allows to extend the use of insects as a potential source of chitin and chitosan and confirms the role of the source and the processes in the determination of their characteristics.
•Extraction of chitin is optimized by adapting the process to the studied source Tenebrio Molitor.•Porous or filamentous surface structure influences reactivity and purity of chitin.•Chitosan yields from Tenebrio Molitor are comparable to or better than the industrially used sources.•Comparison of the results with Black Soldier Fly confirms the role of the source and the process.•Breeding insects can now be carried out to produce proteins, chitin and chitosan samples.