Papers by Keyword: Chitin

Abstract: The conversion of seafood waste into valuable materials is essential for advancing seafood sustainability. Crab shells, which are a major byproduct, generate a large volume of waste annually and are a key source of chitin and chitosan. This study explores the extraction and characterisation of chitin and chitosan from Irish brown crab (Cancer pagurus) shell waste using chemical methods. Samples of crab shell waste (CSW), extracted chitin (CT) and chitosan (CTS) were analysed and compared to commercial chitosan (CTS-c) in terms of chemical, thermal and structural properties. The extraction process included steps of demineralisation, deproteinisation, decolourisation and deacetylation, yielding 17.60% CT and 50.45% CTS, which aligns with previously published values. FTIR analysis confirmed structural changes from CSW to CT followed by CTS, shown by distinct spectral shifts, with CTS exhibiting a degree of deacetylation (DD) of 78.53%, comparable to CTS-c (79.53%). DSC findings showed increased enthalpy, ΔH from 72.58 J/g (CSW) to 253.28 J/g (CTS), indicating improved thermal stability. SEM images displayed morphological transformations from porous CT to denser CTS, with porosity measured by ImageJ changing from 2.87% (CSW) to 18.60% CT before decreasing to 2.71% (CTS). These outcomes highlight the feasibility of valorising Irish crab shell waste into high-quality chitin and chitosan suitable for use in end-product applications, thus promoting the concepts of a circular economy.

Abstract: Chitin is a biopolymer that can be used as a candidate material for a strong and environmentally friendly glass adhesive. In the form of nanoparticles with needle-like morphology and attractive functional groups in the form of amide and hydroxyl, Chitin Nanoparticle (ChNP) shows a strong Van der Walls adhesive force against glass. In the study, ChNP was successfully isolated from crab shells from the sea of Lombok. The isolated ChNP has a characteristic size around 351 nm with -chitin conformation and needle-shaped morphology. Based on the results of shear strength testing, 0.42 mg of ChNP can withstand a load of 21 kg and the addition of Gum Arabic (GA) and Hen Egg White lysozyme (HEWL) in a ratio of 1: 1 to ChNP succeeded in increasing adhesion by 72%.

Abstract: Shrimp waste contains a high content of chitin which is potential to be used as a chitosan’s precursor. Synthesis of chitosan is usually done by deproteination, demineralization, and deacetylation process. Deacetylation of chitin from shrimp waste isolated by autolysis, has been a few reported before. The chemicals involved in autolysis are less harmful and easier to treat before their disposal. Hence, this paper investigates the effect of base type and concentration on the degree of deacetylation of chitosan from chitin isolated by autolysis. Autolysis was carried out by an incubation at pH 2 using sulfuric acid for 10 d. Demineralization was performed by immersion in hydrochloric acid pH 1 for 24 h. The deacetylation of chitin was carried out at 120 °C for 120 min using two different bases, which are NaOH and KOH, respectively. The determination of chitosan’s degree of deacetylation (DD) was carried out using a semi-quantitative method from IR spectra. The use of KOH resulted in the obtained DD of less than 20%, while the NaOH usage produced around 50% of DD. Then, the NaOH was chosen and studied further to obtain a suitable DD for film applications, which is 40 – 99%. The deacetylation of chitosan was carried out by varying NaOH concentration from 60 to 70% (w/v). High concentration of NaOH tends to increase chitosan’s DD and slightly decrease the yield. The optimum concentration of NaOH was obtained at 70% (w/v) producing DD of 53.50±0.83% and yield of 47.66±0.28%. Chitosan synthesized using 70% concentration of NaOH produced a relatively homogeneous thin film. Polyaniline was then introduced to the film to obtain a prototype of smart packaging. This smart packaging was able to detect the pH changes proven by the change of its color.

Abstract: Chitin, as well as its deacetylated variant chitosan, has a wide range of applications in biomedical, agricultural, environmental and food industries. Currently, chitin is commercially produced from crustacean shells rather than fungal or insect sources. In this study, chitin from different lifecycle phases of the black soldier fly (BSF) was extracted and deacetylated into chitosan. Both BSF chitin and chitosan were further subjected to FTIR analysis. The chitin extraction yield % was obtained according to the following order: coccoon>larvae>prepupae. On the other hand, the yield of chemical deacetylation of chitin into chitosan showed a different trend: larvae>prepupae>coccoon. All samples have a deacetylation degree (DD) of more than 90 % except for chitosan from prepupae. FTIR profiles indicated all chitin extracted were in the α-form while the deacetylated chitosan matched closely to the commercially available chitosan. Overall, this study indicated that BSF biomass from different lifecycle phases could be a promising alternative resource for industrial chitin and chitosan production.

Abstract: In this study, the degree of acetylation (DA) and degree of deacetylation (DDA) were determined by Fourier Transform Infrared Spectroscopy (FT-IR) analysis, and their viability was evaluated by the cytocompatibility test with L132 epithelial cells, from samples of chitin and chitosan extracted of Cryphiops caementarius. FT-IR measurements resulted in the successful determination of DA and DDA. Particularly the results showed that, the chitosan CHT-C has the highest DDA (93%), while viability tests employed to determine the cytotoxicity of chitin and chitosan showed that the cell survival rate of CH-C and CHT-C are 130% and 75% respectively while commercial CHT has a rate of 80% approximately, demonstrating that the CH-C (chitin) a favorable behavior against L132 cell.

Abstract: In this study, chitin-cellulose films (CC) and nanocomposite (NC) films were successfully laminated to thermoplastic starch (TPS). These were prepared using adhesive, controlled heated compression, and heated compression with adhesive. Lamination was investigated by utilizing direct tensile adhesion strength test to acquire the adhesion strength between the two layers. The highest adhesion strength of 0.502±0.036 MPa resulted for CC/TPS. Combination of failure at the interface and substrate was observed for most CC/TPS laminates. FTIR spectra indicated presence of -NH groups from chitin and -OH groups from starch and cellulose that could improve interfacial adhesion by hydrogen bonding. Scanning Electron Micrographs (SEM) showed a rough surface of chitin-cellulose films, and the clear continuity of CC film with TPS. An increase in modulus from from 0.342 ± 0.020 MPa for TPS to 1.059 ± 0.162 for CC/TPS and 0.939 ± 0.143 MPa for NC/TPS.

Abstract: In this work, chitin-based material has been proposed for removing the purple NR5 dye in aqueous solution. The material chosen is from shrimp shell: Aristeus antennautus. This biomaterial is used as a raw form. The adsorption isotherms obtained showed a behavior of L3a indicating the passage of monolayer to multilayer adsorption. The results are well correlated with the BET model, (R²>0.99). And the maximum monolayer adsorption capacity was found to be 667.33 mg/g. The kinetic data were evaluated using pseudo first order, pseudo second order and the intraparticle diffusion models. The chemical nature of the biomaterial is confirmed by Fourier Transform infrared spectroscopy (FTIR).

Abstract: Solid waste management is one of the important areas focused by several researchers as it reduces environmental degradation, and offers useful or value added products. Fishery waste is significantly available in coastal areas and food processing industries which are a threat to the environment. Reuse or recycling is a better option to reduce the disposal of fishery waste. In this study, two different fishery wastes were investigated for their use for waste water treatment application. Chitosan was prepared from fishery and shrimp wastes by alkaline N-deacetylation process. Further Chitosan was characterised by the Fourier transform infra red analyser (FTIR), X-ray diffraction (XRD) and Viscosity-molecular weight. The FTIR results showed a more detailed structure of α-chitin in the region of O-H, N-H and CO stretching region. The FTIR spectrum was used to determine the chitosan degree of acetylation (DA).

Abstract: Chitosan is a natural biopolymer derived by deacetylation of chitin from the two main sources of crustaceans, shrimp and crabs. Chitosan, which is soluble in acidic solutions, is used in many applications (biomedical/pharmaceutical, water engineering, food, cosmetics). There have been many researchers who have developed a process of deacetylation of chitin from shrimp shells waste by thermochemical or enzymatic methods. However, application of ultrasonic irradiation for chitin deacetylation has received little attention. In this work, the deacetylation of chitin with concentrated sodium hydroxide was performed using ultrasound irradiation (80 W, 42 kHz). The reaction time and degree of deacetylation were compared with conventional process. Results showed that under the same condition, the degree of deacetylation was similar. However, the use of ultrasonic irradiation decreased the reaction time, showing that this method may be a promising alternative method to the conventional method.

Abstract: The market share of biodegradable polymers from renewable sources has grown rapidly in the plastic industry. Properties of the polymers from renewable resources can be enhanced through blending and composite formation. Fermented chitin is a by-product in a bacterial prawn waste fermentation for protein recovery which has undergone mild chemical treatment producing treated fermented chitin (TFC). TFC was further acid hydrolysed to produce chitin nanowhiskers (TFCNW). The chitin nanowhiskers was used as filler in polylactic acid (PLA) through solution casting method. Atomic Force Microscopy showed TFCNW particles are uniformly dispersed in PLA matrix but tends to agglomerate as TFCNW loading increased. Tensile strength of the biocomposite film increased up to 12.4 MPa at 2 phr TFCNW which it decreased with further addition of TFCNW. The Young’s modulus increased with increasing of TFCNW content up to 3.69 GPa. However, elongation at break of the biocomposite film decreased by 66 % upon addition of TFCNW when compared to pure PLA.