Physicochemical and bio-metabolite characterizations of chitosan isolated from American cockroach (Periplaneta americana) and cricket (Acheta domesticus)

Background: Chitosan is gaining increased research interest due to its wide range of potential applications in the field of biotechnology, medicine and pharmacology, agriculture, textiles, cosmetics and wastewater treatments. This study was designed specifically to explore locally available chitosan from American cockroaches (Periplaneta americana) and cricket (Acheta domesticus) as an alternative source of chitosan for industrial application. Methods: Chitosan was extracted by alkaline deacetylation of chitin and were physicochemically characterized using Fourier Transformed Infrared Spectroscopy (FTIR), scanning electron microscope (SEM), degree of deacetylation (DD), solubility and Gas Chromatography-Mass Spectrometry. Results: The yielding proportion of Chitosan obtained from P. americana and A. domesticus were 99.7 and 90.6%. The cockroach and cricket chitosan have the same degree of deacetylation of 90.3 % and 88.5%respectively. The FTIR Spectroscopy of the chitosan from P. americana and A. domesticus revealed that the obtained chitosan was in alpha polymorphic form. This fact was confirmed by the scanning electron microscope (SEM) which shows the morphology of the chitosans from both insects. Chitosan from Cockroach and crickets compares favourably and were found to exhibit some similarities. It was established that P. americana chitosan was more soluble in dilute acetic acid with about 102.1% solubility, while A. domesticus chitosan had 93%. The GCMS analysis revealed the presence of a class of compounds like benzene derivative, alkene derivative, bicycle derivative, bicycle alcohol derivative, multiple cyclic compounds, saturated tricycle and derivatives of chloroalkane, fatty acid, saturated, and saturated alcohol. Conclusion: Based on all these qualities possessed by the chitosan of both insects, they can replace commercial chitin and chitosan in terms of utilization and applications. Therefore, both insects are promising alternative sources of chitin and chitosan.