Extraction of chitin and chitosan from Hermetia illucens breeding waste: A greener approach for industrial application.

Sustainably exploiting the waste of the black soldier fly (BSF) to produce chitin and chitosan remains a challenge. This work valorizes the pupal cases of BSF for chitin and chitosan extraction. Four chemical extraction processes have been employed. Process 1, the standard method for this source, served as a control. Processes 2 and 3 were designed to assess and select the most effective delipidation method, while the optimized Process 4 involved autoclave conditions (121 °C-2.2 Bar). All chitin derivatives obtained were characterized by FTIR, SEM, XRD, H NMR, TGA, potentiometry, viscosimetry, and ICP-OES. Extraction using Process 4 (P4) proved to be the most efficient, demonstrating a deproteinization efficiency of 94.25 ± 0.6 % in a total reaction time of 1.15 ± 0.08 h and water consumption of 250 ± 26.86 L/kg, significantly lower than in other processes. In terms of yield, this process resulted in chitin and chitosan with respective yields of 34.74 ± 1.15 % and 83.33 ± 1.28 %, outperforming the other methods. Regarding physicochemical properties, P4 produced chitin and chitosan with improved thermal stability, with DTG values of 421 °C and 345 °C respectively. Additionally, the crystallinity of chitin was reduced by 25.68 %. For chitosan, the degree of acetylation (DA) was the lowest, while maintaining a high molecular weight of 220,378 g.mol. These results confirm that P4 is efficient and environmentally friendly, making it well-suited for industrial applications.