Optimization of Demineralization Stage in Chitosan Extraction from Mangrove Crab Shell (Scylla sp.)

Abstract

Mangrove crab shell waste generated from the mangrove crab processing industry in Tarakan City is one of the causes of environmental pollution problems. One way to reduce the risk of pollution is to process mangrove crab shell waste into chitosan. Modifications at the demineralization stage were carried out because mangrove crabs contain high minerals, reducing the quality of the chitosan produced. This study aimed to optimize the demineralization step in the extraction of chitosan from mud crab shells (Scylla sp.) through analysis of yield, moisture content, ash, total nitrogen, FTIR, degree of deacetylation, and SEM-EDX. The treatment in this study was at the demineralization stage, and different comparisons were made between mud crab shell powder and 1N HCl, namely a (1: 10) and b (1:15). The results of this study showed that the quality of chitosan from mud crab shells had yield values, water content, ash content, and total nitrogen (15.08±0.04%, 1.65±0.00%, 2.87±0.07%, 1.35±0.00%) at a ratio of 1:10 and (6.37±0, 04%,1.66±0.01%, 1.75±0.00%, 1.29±0.004%) at a ratio of 1:15. The degree of deacetylation of chitosan a (47%) did not match the three standards because it was below 70%, while chitosan b (76%) was following the Protan Laboratory standard and SNI (≥70%). The elements of mangrove crab shell chitosan detected from SEM EDX analysis consisted of C, O, Ca, Mg, and Al. The detected elements of C and O are components that form chitosan. The best quality characteristics of chitosan were produced at the demineralization stage with a comparison of the sample and 1N HCl b (1:15) treatment because it was proven to be in accordance with chitosan quality standards.