Impact of soaking duration on chitosan yield and functional properties from shrimp shell

This study investigates the effect of varying soaking times on the production of chitosan from shrimp shells. Asample of fresh shrimp shells was obtained from a market in Malacca, Malaysia, and pre-treated by washing,drying, and pulverizing into a homogeneous powder. The synthesis process involved three primary steps:demineralization, deproteinization, and deacetylation. Each step was executed under different conditions forfour samples (S1-S4) to examine the impact of soaking duration on chitosan yield and properties.Demineralization was achieved using 1 M HCl, while deproteinization involved treatment with 1 M NaOH, bothwith varying soaking times. Deacetylation was conducted with 12.5 M NaOH at different temperatures anddurations. The resultant chitosan was characterized using Fourier Transform Infrared (FTIR) spectroscopy, X-raydiffraction (XRD), and UV-Vis spectroscopy. The FTIR spectra confirmed the presence of characteristic chitosanfunctional groups, with higher degrees of deacetylation (DD%) corresponding to increased soaking times. XRDanalysis indicated an amorphous structure for all samples, with S4 displaying the lowest crystallinity at thehighest DD%. UV-Vis analysis confirmed that all samples were soluble in 1% acetic acid, suggesting good purity.The findings demonstrate that while soaking times affect the DD% and crystallinity of chitosan, all samplesremained soluble and suitable for further applications. This work demonstrates that while soaking times affectthe DD% and crystallinity of chitosan, all samples remained soluble and suitable for further applications. Thisstudy provides insights into optimizing chitosan production with variations in soaking time conditions.