Extraction and characterization of chitin from Oratosquilla oratoria shell waste and its application in Brassica campestris L.ssp

Mantis shrimp waste (Oratosquilla oratoria) is a good source of chitin. The applicability of microwave-assisted organic acids and proteases for extracting chitin from mantis shrimp shell waste was evaluated, and the extracted-chitin was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Moreover, the effects of nanochitin on the growth of pak choi ( Brassica campestris L.ssp.) were also investigated. The results indicated that alkaline protease (4000 U/g, microwave heating at 60 °C, 10 min) and malic acid (5%, 320 W, 5 min) exhibited excellent potential for deproteinizing and demineralizing shells. The deproteinization and demineralization yields were 92.78% and 94.11%, respectively, and the chitin yield was 15.6%. The extracted-chitin had a highly porous structure and exhibited excellent crystallinity and thermostability compared with chitin prepared by traditional chemical methods. Furthermore, 0.003% nanochitin significantly enhanced photosynthesis, which improved the pak choi fresh weight by 22.94%, and improved the accumulation of isothiocyanates in its leaves. This study provides an alternative approach for the high-value utilization of mantis shrimp waste, and reveals the potential of chitin for application in agricultural production.