The role of base types and concentration in the deacetylation process ofmanufacturing chitosan from green mussel shells (Perna viridis)

n the food industry, chitosan is useful as a preservative, edible film, heavy metal binder, and so on. Chitosan is produced by removing the acetyl groups in chitin using a strong base. Green mussel (Perna viridus) shells, which are waste from the fishing industry, have the potential to be utilized as raw materials for chitosan production because they are estimated to contain about 15-35% chitin. The deacetylation process was conducted using alkali at high temperatures, leading to the release of the acetyl group (CH3CHO-) from the chitin molecule. The choice of a strong base over an acid for deacetylation, particularly in the context of converting chitin to chitosan, is rooted in the mechanism of the reaction and the desired product properties. The purpose of this study was to determine the influence of the type and concentration of bases in the deacetylation process on the characteristics of chitosan produced from green mussel shells. The experimental design used was a completely randomized factorial design with two factors. The first factor was the strong base (NaOH, KOH, and a mixture of NaOH and KOH) used, while the second factor was the base concentration (40%, 50%, and 60%). The data obtained were analyzed using analysis of variance (ANOVA) and Duncan multiple range test (DMRT). The results revealed that the type and concentration of the base affected the yield, deacetylation degree, water content, ash content, nitrogen content, and solubility. The best treatment in this study was a KOH treatment with a concentration of 60%, resulting in a deacetylation degree of 78.95%, a yield of 3.20%, a moisture of 2.035, an ash content of 0.26%, a nitrogen content of 6.38%, and a solubility of 99.19%. Identification of chitosan functional groups was conducted on chitosan from the best treatment using FT-IR Spectrophotometer. From the results of FT-IR spectra analysis, the functional groups present in the sample were –OH, C-H, and N-H, which were the main functional groups of chitosan.