Response Surface Optimization and Kinetics of Isolating Chitin from Pink Shrimp (Solenocera melantho) Shell Waste

Response surface methodology has been applied to the isolation of chitin from pink shrimp shell powder. The optimal deproteinization condition occurs at 75 °C, 2.5 N NaOH. A minimal solution to solid ratio of 5 mL/g is required to maintain fluidity during deproteinization. Deproteinization exhibits two-stage first-order reaction kinetics. The maximum deproteinization rate constant approaches 0.1 min -1 when the protein content is decreased from 16% to slightly above 7%. After the first 30 min, the deproteinization rate constant could decrease up to 2 orders of magnitude. The optimal demineralization condition is around 1.7 N HCl, with an acid solution to solid ratio of 9 mL/g at ambient temperature. Demineralization could be described as a pseudo-first-order reaction. The demineralization rate constant ranges from 0.00020 to 0.017 min -1 .