Isolation and Characterization of Chitin and Chitosan Prepared Under Various Processing Times

Abstract

Generally production of chitosan from crustacean shells consists of 4 steps, i.e. deproteinization, demineralization, decolorization and deacetylation. Simplification of chitosan production by elimination of deproteinization and/or demineralization, or reducing of reaction time would give many advantages, e.g. reduction of processing time and cost production due to reduction of chemical and power usage. The objectives of this research were to prepare chitosan under various processing times and to characterize the obtained chitin and chitosan. Chitin was prepared under various deproteinization times (0, 15, 30 min at 90 ºC using NaOH 2N) and demineralization times (0, 15, 30 min at ambient temperature using HCl 2N). Chitin was then bleached using aceton/etanol (1:1) for an hour. Deacetylation was achieved by treatment of chitin under condition at 120 ºC for 5 hr using NaOH 50%. Ash and nitrogen content, and degree of deacetylation of chitosan were evaluated. Demineralization and/or deproteinization times influenced the quality of chitin. Chitin and chitosan prepared without demineralization had white and chalky appearance, whereas the other chitosan were off-white in color. Ash and nitrogen contents of the chitosan products were 0.18 - 32.40% and 3.56 - 7.59%, respectively. Chitosan prepared under various processing times, except chitosan without demineralization treatment, had degree of deacetylation ≥ 70%. Keywords: chitosan, deproteinization, demineralization, deacetylation, processing times

Characteristics and antibacterial activity of chitosan nanoparticles from mangrove crab shell (Scylla sp.) in Tarakan Waters, North Kalimantan, Indonesia

“…Based on the study results, nitrogen content was 1.32 ± 0.06% which was in accordance with the chitosan quality standard of EFSA (2010) (Table 1). Poeloengasih et al (2008) also noted that the nitrogen content of chitosan was in the range of 3.56%-7.59%. Demineralized chitosan exhibits high nitrogen content.…”

Physicochemical Characterization and Antimicrobial Analysis of Vegetal Chitosan Extracted from Distinct Forest Fungi Species

“…After that, the mixture was filtered and rinsed until the pH reached 7.0. The residue was then oven-dried at 60 °C for 24 h. After this stage, the chitin was discolored by soaking it in ethanol for 24 h [ 9 , 10 ]. The chitin was then filtered out, rinsed, and dried for 24 h at 60 °C.…”

Advances in Functional Chitin Materials: A Review

“…In the context of Green Chemistry and Sustainability, we should point out that the use of chitin in any application today is hampered by the method it is isolated. Chitin is isolated primarily from crustacean biomass where it exists in a matrix of minerals (calcium carbonate and phosphate) and proteins, with small amount of lipids (such as, for example, unsaturated fatty acids) and astaxanthin; other biomass sources such as fly larvae, squid pen or fungi present significantly less volume supply. − Chitin materials are typically prepared from one or the other chitin types: commercially available chitin obtained by pulping or chitin produced by ionic liquid extraction . At the same time, the method of chitin isolation dramatically affects whether the material can even be prepared, and what properties it will exhibit if it can …”

“…32 This is because the traditional method of chitin isolation, pulping, results in variable reduction in molecular weight (MW), nonuniform chain scissions, and unwarranted deacetylation (decrease in degree of acetylation, DA), producing a polymer of low quality, with inconsistent characteristics. 33 Specifically, pulping includes demineralization with HCl, deproteinization with NaOH, and a discoloration with organic solvents and/or oxidants, at relatively high temperatures (60− 100 °C) for 12−48 h. 30,34 Isolation conditions mainly depend on the source and the species, with different sources and types of raw materials requiring custom modifications to the chemical treatment (i.e., concentrations of NaOH and/or HCl, temperature and time variations) to isolate chitin. 33 In this review, we will call chitin produced from this commercial technology as "commercial chitin.…”