Degree Of Deacetylation Research Articles

Physicochemical Properties of Chitosan from Green Mussel Shells (Perna viridis): A Comparative Study.

Green mussel shells (Perna viridis) are generated in huge amounts and discarded as waste materials. Such waste may be used to produce biopolymer materials such as chitosan. The physicochemical properties of chitosan prepared from different sizes of green mussel shells (small size (CHS): ≤5.00 cm in length and big size (CHB): >5.01 cm in length) were characterized and compared with commercial chitosan (CH). Furthermore, the mechanical and physicochemical properties of the blended films were also investigated. The results of the physicochemical properties showed that CHS and CHB were quite different from CH. The degree of deacetylation of CHS, CHB, and CH was found to be 32.71%, 52.56%, and 70.42%, respectively (p < 0.05). The water- and fat-binding capacities of CH were higher than those of CHS and CHB. Structural differences between CHS, CHB, and CH were studied using Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). Significant increases in thickness, water vapor permeability, and strength of the blended films were found when the extracted chitosan was added (p < 0.05). However, further study is needed to improve the chitosan extraction process, which can enhance the physicochemical properties of the obtained chitosan and be widely used in many industries.

Extraction of Chitin from Black Soldier Fly (Hermetia illucens) and Its Puparium by Using Biological Treatment.

Chitin is the second-largest natural polymer polysaccharide in nature. Due to its important physical and chemical properties and excellent biocompatibility, safety, and biodegradability, it is widely used in agriculture, medicine, food, environmental protection, and other fields. However, traditional extraction methods cause environmental pollution and damage the structure of chitin. Bioprocessing is an emerging technology that shows great potential. In this research, the puparia and adults of black soldier fly (BSF) (Hermetia illucens L.) were used as raw materials. A continuous fermentation method was designed to extract chitin, by using Bacillus subtilis S4 and Acetobacter pasteurianus AS1.41. The Fourier transform infrared spectroscopy identification results showed that the extracted sample was α-chitin. Under continuous fermentation conditions, the deproteinization (DP) rate, demineralization (DM) rate, chitin yield (CY), and deacetylation degree (DD) of puparium chitin were 33.33%, 94.92%, 59.90%, and 18.52%, respectively. Meanwhile, the DP rate, DM rate, CY, and DD of adult chitin were 46.63%, 90.93%, 47.31%, and 37.38%, respectively. For BSF, B. subtilis S4 had a certain DP ability, and A. pasteurianus AS1.41 had a good DM effect. Moreover, BSF at different developmental stages could affect CY, and a higher concentration of NaOH was more favorable for deacetylation. Overall, simultaneous continuous fermentation could be a new biological approach to extract chitin from BSF.

Extraction and Physicochemical Characterization of an Environmentally Friendly Biopolymer: Chitosan for Composite Matrix Application

Chitosan, which is a derivative of chitin, is particularly popular due to its biodegradable and renewable nature. However, the properties of chitosan can be inconsistent due to the extraction process and its natural origin, which poses a challenge to its use in composite materials as a matrix. The properties of chitosan can be tuned by controlling the degree of deacetylation (the extent to which acetyl groups are removed from chitin to form chitosan) and molecular weight. This paper presents a detailed study on the extraction and characterization of chitosan from shrimp shells. The structural thermal and mechanical characterization were studied using several techniques: Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry. The intrinsic viscosity and deacetylation degree were determined using various methods. The results showed an average degree of deacetylation of 77%. The chitosan films exhibited a high tensile strength of 43.9 MPa and an elongation at break of 3.14%. The thermal analysis revealed that the films had a glass transition temperature of 88 °C and a maximum thermal degradation temperature of 320 °C. The findings of this research could contribute to the development of chitosan-based materials with improved properties, leading to its wider adoption in the future for composite matrix application. The simple and efficient method used for the extraction and purification of chitosan from shrimp shells makes it a cost-effective and eco-friendly alternative to synthetic polymers.

Effect of deacetylation of chitosan on physicochemical properties, antioxidant and antibacterial activities of chitosan-mannose derivatives.

This paper investigates the physical, chemical, and antibacterial properties of water-soluble chitosan derivatives. Preparation of the water-soluble chitosan derivatives was done by the Maillard reaction (MR) between chitosan (the degree of deacetylation (DD) being 50%, 70%, and 90%) and mannose. No organic reagent was used in the process. Systematic evaluations of the effects of chitosan DD on the reaction extent, the structure, the composition, as well as the physicochemical properties, antioxidant properties, and bacterial inhibitory properties of the finished chitosan-mannose Maillard reaction products (Mc-mrps) were carried out. Based on the experimental data obtained from the Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Pyrolysis-gas chromatography-mass analysis (PY-GC-MS), and 1H-NMR, the Mc-mrps formed from chitosan with different DDs had different structures and components. An increase in the DD of chitosan led to a significant increase in the degree of reaction, color difference (△E), and solubility (p<0.05). The zeta potential and particle size of the Mc-mrps were also influenced by the DD of chitosan. Additionally, the antimicrobial action against Gram-positive (S.aureus and Bacillus subtilis) and Gram-negative bacteria (E.coli and Salmonella typhimurium) as well as antioxidant activity were enhanced by the incorporation of mannose. This was also achieved by the increase of the DD of chitosan. The results of the study suggest that chitosan was derived with mannose to yield a novel, water-soluble polysaccharide with better antioxidant and antimicrobial activities. The DD of chitosan had a significant effect on the properties of the Mc-mrp, which can serve as a reference point for the subsequent preparation and application of such derivatives. This article is protected by copyright. All rights reserved.

Effect of Chitooligosaccharide Characteristics from Several Types of Shells on Prebiotic Activity : A Brief Review

Seafood is one of the foods favored by the community and has waste that is not used properly, such as shells. The component contained in the highest shell is chitin, this chitin content can be processed into chitosan. Chitosan is obtained from a process, namely enzymatic and chemical hydrolysis and this process can also be used to obtain chitooligosaccharides. Chitooligosaccharides are complex compounds of the glycoprotein group which have -1,4 glucosamine bonds. Chitooligosaccharides can act as prebiotics. Recently, there has been a lot of research on the characteristics and prebiotic activity of chitooligosaccharides. However, there is a lack of information regarding the relationship between the characteristics and prebiotic activity of chitooligosaccharides mainly from different sources of chitooligosaccharides. Therefore, the aim of this review is to summarize and collect viewpoints regarding the relationship of characteristics with prebiotic activity. The characteristics of chitosan of each type of shell have differences, the main parameter is the degree of deacetylation. The high degree of deacetylation and yield can affect the yield on the characteristics of the chitooligosaccharides produced. Thus, the higher the degree of deacetylation of chitosan, the higher the degree of deacetylation of chitooligosaccharides, so that it can show high prebiotic activity because probiotic bacteria can grow well. Accordingly, this summary can contribute to explaining a comprehensive review of the characteristics of chitooligosaccharides on the prebiotic activity of underutilized and safe materials for consumption.

Extraction of chitosan from biologically-derived chitin by bacterial chitin deacetylase: Process optimization and product quality assessment

Commercial chitosan manufacturing process relies on strong chemical treatment on chitin that generates chitosan with undesirable properties and leads to environmental pollution. To overcome the adverse consequences, enzymatic chitosan preparation from chitin was undertaken in the current study. A potent chitin deacetylase (CDA) producing bacterial strain was screened and subsequently identified as Alcaligens faecalis CS4. After optimization 40.69 U/mL of CDA production was achieved. By treating the organically extracted chitin with partially purified CDA chitosan yield of 19.04 % was attained having 71 % solubility, 74.9 % degree of deacetylation, 21.16 % crystallinity index, 246.4 kDa molecular weight and 298 °C highest-decomposition temperature. FTIR and XRD analysis revealed characteristics peaks respectively within 870–3425 cm−1 wavenumber and 10°-20°, for enzymatically and chemically extracted (commercial) chitosan that endorses their structural similarity which validated through electron microscopic study. At 10 mg/mL chitosan concentration 65.49 % DPPH radical scavenging activity endorsed its antioxidant potential. Minimum inhibitory concentration of chitosan was 0.675, 1.75, 0.33 and 0.75 mg/mL for Streptococcus mutans, Enterococcus faecalis, Escherichia coli and Vibrio sp., respectively. Mucoadhesiveness and cholesterol binding properties were also exhibited by extracted chitosan. The present study opens a new vista for eco-friendly extraction of chitosan from chitin that is proficient and sustainable in environmental perspective.

EFFECT OF MICROWAVE IRRADIATION TIME TO DEACETYLATION PROCESS OF CHITIN FROM SHRIMP SHELLS

Microwaves have been used in various organic synthesis applications. The use of microwaves provides many advantages, including relatively short start-up and heating times, energy efficiency and process costs, easy and precise process control, selective heating, better final product quality, and improved dry material quality. Microwaves were used in this study to convert chitin into chitosan and to determine the effect of deacetylation time on the degree of deacetylation of chitosan, which was in accordance with the Indonesian National Standard (SNI 7949:2013). The chitin deacetylation process was carried out by varying the heating time to 5, 7, 11, and 15 minutes with a power of 350 W. Two grams of chitin were mixed with 40 mL of 70% NaOH solution in a beaker. The mixture was put in a microwave at a constant temperature of 70 °C. Chitosan was washed until neutral and then dried in an oven. The degree of deacetylation (DD) was analyzed using Fourier Transform Infrared (FTIR) spectroscopy. The results showed that A deacetylation degree of 79.96% was achieved at a reaction time of 15 min. The water content of chitosan was determined to be 9.15%.

Characterisation and Analysis of Chitosan Extract from Artemia franciscana Using SEM, FT-IR and XRD Studies

Introduction: Artemia franciscana is one of the best animal models which is used in various fields. After the hatching of Artemia the shell wastes are used for Chitosan extraction. The extraction process consumes less time when compare with other shells because of its shell size.&#x0D; Materials and Methods: The Chitosan extract was prepared using Artemia shells. The Physico-chemical properties were analysed and characterization of Chitosan extract was done using SEM, XRD and FT-IR studies.The physicochemical properties of the extracted chitosan indicate that it has optimum values desirable for wound healing applications. Chitosan has high water and fat binding capacity that can help to maintain a moist environment on the wound surface and control inflammation, respectively. The degree of deacetylation (DD) of chitosan is critical in determining its biological activities. The DD value obtained in this study was 84.77%, indicating that the chitosan sample had a high degree of deacetylation. Outcomes: The morphology of the chitosan membrane is an important factor that influences its properties and potential applications, including wound healing.&#x0D; Results: The SEM images obtained in this study revealed that pure chitosan exhibited a nonporous, smooth membranous phase with dome-shaped orifices, microfibrils, and crystallites. The XRD analysis results suggest that the chitosan used in this study is highly crystalline, with both crystalline and amorphous regions enhancing its bioactivity and biocompatibility, making it a promising material for wide range of application in medicine. The crystalline and amorphous structure of Chitosan is analysed by the XRD, SEM and FT-IR reveals its wide range of applications in medicine.

Fireproofing flammable composites using mycelium: Investigating the effect of deacetylation on the thermal stability and fire reaction properties of mycelium

This paper presents research findings on the influence of alkaline deacetylation on the thermal stability and fire reaction properties of non-pathogenic Basidiomycota fungi (mycelium) grown in molasses. The relationship between deacetylation conditions, such as incubation time and NaOH concentration, and the thermal and fire reaction properties of mycelium was investigated. The degree of deacetylation was also examined for its influence on the high-temperature thermal stability of mycelium, such as char formation. The findings indicated that the high-temperature thermal stability increased as the degree of deacetylation increased due to the conversion of chitin into chitosan as well as the presence of char-promoting hydroxyl‑terminated polysaccharide moieties. The study further investigated the influence of hollow glass microspheres on the thermal properties and microscale combustion behaviour of unmodified and deacetylated mycelium. This study provides an in-depth analysis of the thermal degradation mechanisms that govern the thermal stability and char-forming ability of unmodified and deacetylated mycelium. Additionally, the link between the thermal stability and fire reaction properties of mycelium and its deacetylated derivatives was established. Finally, the effectiveness of unmodified and deacetylated mycelium mats for fireproofing flammable glass fibre-reinforced epoxy laminates exposed to a simulated moderate-intensity fire was evaluated.

FABRICATION OF CHITOSAN BIOPOLYMER FROM PEARL OYSTER SHELLS (Pinctada maxima) FOR MEDICAL APPLICATIONS

Chitosan is one of the biopolymers that has recently been developed in the medical field. Chitosan is biocompatible, biodegradable, and non-toxic, so it is safe for the human body. This study aimed to identify the characteristics of chitosan isolated from pearl oyster shells. Chitosan is obtained through three stages: deproteination, demineralization, and deacetylation. Characterization of chitosan is done physically and chemically including organoleptic test, yield calculation in each step of isolation, FTIR, and XRD. Isolated chitosan identified deacetylation degree and functional group with FTIR. While the crystal structure was determined using XRD. The results showed that chitosan powder has a beige color with a final yield of 7,06%. The characterization of FTIR shows that synthesized pearl oyster shells have successfully formed chitosan compounds with a deacetylation degree of 81,50%. Another characteristic is the crystal structure obtained; chitosan has orthorhombic unit cells with a degree of chitosan crystallinity of 36,94%. Based on the result, chitosan has met several standards in medical applications as a biomaterial.

Impact of molecular weight and deacetylation degree of chitosan on the bioaccessibility of quercetin encapsulated in alginate/chitosan-coated zein nanoparticles

This work aimed at studying the effect of molecular weight (MW) and deacetylation degree (DD) of chitosan on the quercetin bioaccessibility encapsulated in alginate/chitosan-coated zein nanoparticles (alg/chiZN). The chitosan coating layer produced nanoparticulate systems with good stability parameters, high encapsulation efficiency (EE) and a higher bioaccessibilty of quercetin after in-vitro digestion. By increasing the DD of chitosan, the ζ-potential of the colloidal system significantly increased (≥27.1 mV), while low and very low MW chitosans generated systems with smaller particle sizes (≤ 277.8 nm) and polydispersity index [PDI (0.189)]. The best results, in terms of EE (≥84.44) and bioaccessibility (≥76.70), were obtained when the systems were prepared with low MW chitosan and high DD. Thus, the alg/chiZN nanocapsules may be a promising delivery system for improving the quercetin bioaccessibility or other compounds with a similar chemical nature, especially when higher DD and lower MWs are used.

Synergistic depolymerisation of alginate and chitosan by high hydrostatic pressure (HHP) and pulsed electric fields (PEF) treatment in the presence of H2O2

Physically-induced depolymerisation procedures are often preferred for obtaining alginate and chitosan oligosaccharides as they either do not use or make minimal use of additional chemicals; therefore, separation of the final products is facile. In this work, solutions of three types of alginate with different mannuronic and guluronic acid residues ratio (M/G ratio) and molecular weights (Mw) and one type of chitosan were non-thermally processed by applying high hydrostatic pressures (HHP) up to 500 MPa (20 min) or pulsed electric fields (PEF) up to 25 kV cm−1 (4000 μm) in the absence or presence of 3 % hydrogen peroxide (H2O2). The impact on the physicochemical properties of alginate and chitosan was investigated by rheology, GPC, XRD, FTIR, and 1H NMR. In the rheological investigations, the apparent viscosities of all samples decreased with increasing shear rate, indicating a non-Newtonian shear-thinning behaviour. GPC results reported Mw reductions that ranged between 8 and 96 % for all treatments. NMR results revealed that HHP and PEF treatment predominantly reduced the M/G ratio of alginate and the degree of deacetylation (DDA) of chitosan, whilst H2O2 promoted an increase in the M/G ratio in alginate and DDA of chitosan. Overall, the present investigation has demonstrated the feasibility of HHP and PEF for rapidly producing alginate and chitosan oligosaccharides.

Effects of the Degree of Deacetylation on the Single-Molecule Mechanics of Chitosans.

Chitosan is one of the most prevalent biomass materials, and its physicochemical and biological characteristics, such as solubility, crystallinity, flocculation ability, biodegradability, and amino-related chemical processes, are directly connected to the degree of deacetylation (DD). However, the specifics about the effects of the DD on the characteristics of chitosan are still unclear up to now. In this work, atomic force microscopy-based single-molecule force spectroscopy was used to study the role of the DD in the single-molecule mechanics of chitosan. Even though the DD varies largely (17% ≤ DD ≤ 95%), the experimental results demonstrate that the chitosans exhibit the same natural (in nonane) and backbone (in dimethyl sulfoxide (DMSO)) single-chain elasticity. This suggests that chitosans have the same intra-chain hydrogen bond (H-bond) state in nonane and to which these H-bonds can be eliminated in DMSO. However, when the experiments are carried out in ethylene glycol (EG) and water, the single-chain mechanics are increased with the increases of the DD. The energy consumed to stretch chitosans in water is larger than that in EG, indicating that amino can form a strong interaction with water and induce the formation of the binding water around the sugar rings. The strong interaction between water and amino may be the key factor for the well solubility and chemical activity of chitosan. The results of this work are anticipated to provide fresh light on the significant role played by the DD and water in the structures and functions of chitosan at the single molecular level.

Evaluation on the physicochemical characterization of chitosan from autochthonous fermentation of prawn shell

Conventional chitosan synthesis via chemical route is polluting and results poor quality chitosan. Here, autochthonous fermentation of prawn shell waste was carried out as an alternative to existing chemical and biological synthesis methods. Prawn shell waste was incubated in sugarcane molasses at 10% (w/v) as carbon source and different concentration of salt; 2.5, 5.0 and 7.5% (w/v) in an airtight fermenter for 14 days. The physicochemical characterization of autochthonously fermented chitosan (AFC) were analysed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and elemental analyser (EA). The degree of deacetylation (DD%) of AFC with 5% (w/v) salt concentration was the highest among other AFC with different salt conditions and control setups at 73.9%, while XRD showed degree of crystallinity of 96.81% and EA showed carbon/nitrogen ratio of 7.28%. By comparison, commercial chitosan had degree of deacetylation (DD%) of 78.47%, carbon/nitrogen ratio of 6.49% and degree of crystallinity of 84.54%. In conclusion, physicochemical characteristics of AFCs were comparable to commercial chitosan.

Endotoxin contamination of nanoparticle formulations: A concern in vaccine adjuvant mechanistic studies.

The increasing awareness of endotoxin contamination has raised important questions during the study of the mechanism of action of the vaccine adjuvants. The endotoxins or lipopolysaccharides (LPS) can contaminate vaccine formulations contributing to result misinterpretations of the in vitro and in vivo studies. In this short communication, we considered the suitability of the Limulus amebocyte lysate (LAL) assay to quantify chitosan (Chit) nanoparticle (NP) endotoxin contamination to use them in a comparative in vitro immunotoxicology study using both LPS-free (LF) and non-LF Chit NPs. It was shown that chit NPs had a masking effect on endotoxin levels, hampering a reliable conclusion about the effect of their contamination. Neither non-LF nor LF Chit NPs induced the production of ROS in RAW 264.7 cells or IL-6 and TNF-α in PBMCs. The lack of effect of non-LF NPs was not expected and likely due to the NPs masking effect, more evident for higher deacetylation degree Chit. Overall, to prevent questionable results, nanomaterials should be produced under endotoxin-free conditions.

The Isotherm Studies of Cu (II) Adsorption in Kolong Bangka’s Water onto NaOH-Deacetylated Shrimp Shells Waste Chitin

Isotherm models of Cu (II) adsorption in Kolong Bangka’s water onto NaOH-deacetylated shrimp shells waste chitin was studied. The extraction of chitin was carried out through three steps: deproteinization, demineralization and decolorization. The deacetylated shrimp shells waste chitin (DA-SW chitin) were prepared by the reaction of DA-SW chitin with NaOH at varying concentrations of 20, 40 and 60% (%W) with stirring for 1 hour at room suhue where the degree of deacetylation for varying NaOH concentrations were 65.72, 67.44 and 88.98%, respectively based on our previous research. Increasing the NaOH concentration causes the diffusion rate of OH- increase thus realizing the effectiveness of OH- attack on the carbonyl carbon group in chitin acetamide increasing so that the chitin deacetylation process becomes more effective. In order to study adsorbent equilibrium behaviour, Freundlich and Langmuir isotherm models were used based on Cu (II) adsorption data with variations in contact time 5, 10, 15, 20, 25, and 30 minutes. The results showed that the concentration of Cu (II) decreased with the increase of the degree of deacetylation and contact time. The optimum condition for the percentage of Cu (II) adsorption was achieved in DA-SW chitin with NaOH 60% (where the degree of deacetylation was 88.98%) during 30 minutes was 97.19%. The Cu (II) adsorption isotherm model in Kolong Bangka water onto DA-SW chitin is represented by the Freundlich isotherm model where the Cu (II) adsorption mechanism onto DA-SW chitin causes the formation of multilayer surface which may due to Van der Waals force.

Antifungal Efficacy of Chitosan against Blast Pathogenic Fungi (Magnaporthe oryzae) on Rice (Oryzasativa) Field

Blast disease (caused by Magnaporthe oryzae) is the most damaging disease to rice, and synthetic fungicides has been the primary means of control, however, concerns have been raised about the health risks posed, hence, the need for alternative biological crop protection strategies. This study evaluate the antifungal efficacy of chitosan against blast pathogenic fungi on rice field. Three chitosan (High, Medium and Low Molecular Weight) were purchased while the fourth Chitosan was synthesized from crab shell (CSCS). Faro 52 rice variety was collected from National Cereal Research Institute, Badeggi and Planted on Hydromorphic field. The degree of deacetylation of the synthesized chitosan was 98%. The rice field was inoculated with M. oryzae and treated with chitosan at two weeks after transplanting. The blast severity and incidence and other agronomic data were taken and data were analyzed using Analysis of Variance (ANAOVA) and means separated using Duncan multiple range test (DMRT). Results reveals that blast severity of 6,(highly susceptible) 5, (moderately susceptible) 4(susceptible) and incidence of 28.3%, 20%, 20% and 24.3% in rice plant tag with MMWC1.5%, 1HMWC 2.0%, LMWC2.0% and CSCS 2.0% before treatment with chitosan was observed. However, the severity reduce to 1(resistance) in all and incidence of 9.3%, 2.3%, 1.0% and 2.0% respectively at the end of the treatment. There was no significant difference (P≤0.05) in all other agronomic parameters except for panicle count with highest value (8.53) in HMWC 2.0% and lowest value (5.80) in HMWC 0.5%. Similarly, significant difference was observed in grain yield per plot with highest yield of 717 gram in HMWC 2.0% treated plot while the lowest yield of 190 gram was observed in MMWC 0.5% which was significantly different. It may therefore be concluded that chitosan treatment reduce the severity and incidence of blast pathogen as well as increase grain yield.

Hydrogel Preparation from Shrimp Shell-Based Chitosan: The Degree of Crosslinking and Swelling Study

Chitosan is a natural polymer derived from different starting materials such as fish scales, crab and shrimp shells. Due to the advantages like biocompatibility and biodegradability, chitosan has been widely used in hydrogel development. This current study aims to make chitosan from shrimp shells, synthesize hydrogel from chitosan, and observe the effect of various chitosan preparation treatments on the properties of the hydrogel. The preparation of chitosan was carried out through demineralization, deproteinization, and deacetylation process. HCl concentration during demineralization and NaOH concentration during deproteinization were varied (1; 1,5; 2) M and (1; 1,5; 2) M, respectively. Chitin deacetylation was conducted using 60% (w/v) of NaOH at the temperature of 90oC for 120 min, and chitosan was resulted. Chitosan based hydrogel was then synthesized with the addition of alginate and glutaraldehyde. The effect of HCl and NaOH concentrations during demineralization and deproteinization on the deacetylation degree of chitosan was observed. The effect of deacetylation degree of chitosan on the degree of crosslinking and swelling property of the hydrogel were also evaluated. Chitosan resulted from this study has the optimum degree of deacetylation at 57.28 %, resulting from demineralization by using HCl 2M and deproteinization with NaOH2 M. Higher deacetilation degree of chitosan causing the increase of the degree of cross-linking and decrease of the swelling capacity of the hydrogel. The highest degree of cross-linking is 78.85 %, and the swelling capacity is 47 %.

POTENTIAL CHITOSAN OF WASTE SHELL MANTIS SHRIMP (Harpiosquilla raphidea) AS ANTIBACTERIAL

Mantis shrimp carapace waste can be processed into chitin and chitosan as antibacterial. This study aims to determine the characteristics, and heating time of chitosan on the potential of chitosan as an antibacterial, and to obtain the best chitosan in increasing the durability of catfish meatballs. Experimental research method with the manufacture of chitin and continued with deacetylation with a long heating time to obtain chitosan. The analytical parameters consisted of chemical characteristics (moisture content, ash, and degree of deacetylation), the inhibitory power of chitosan against Escherichia coli and Staphylococcus aureus bacteria, and the effectiveness of chitosan on the quality of catfish meatballs. The results showed that the chemical characteristics of chitosan were water content (K1 3.72%, K2 4.65%, K3 5.24%), ash (K1 2.38%, K2 2.53%, K3 3.69%), and the degree of deacetylation (K1 54.31%, K2 78.04%, K3 79.51%). The results of the inhibition test of chitosan against Escherichia coli and Staphylococcus aureus bacteria using the well method showed an inhibition zone with values (K1 10.11 mm and 10.18 mm, K2 11.52 mm and 11.48 mm, K3 12.15 mm and 11. 70 mm, positive control 14.64 mm and 14.02 mm, negative control 9.25 mm and 7.35 mm). This value indicates that the activity of chitosan as an antibacterial is quite strong. The effectiveness of chitosan on the quality of catfish meatballs with 7% chitosan immersion and storage at room temperature showed that the TPC value of catfish meatballs with chitosan could prolong the shelf life of meatballs until day-2

Extraction and Characterization of Chitosan from the Shell Wastes of Indian Shrimp Using Different Methods of Deacetylation

Objectives: Shrimps are a good source of chitosan, a deacetylated form of chitin, which has several medical and industrial applications. We aimed to convert waste shrimp shells to high-value chitosan product. Methods: The waste shells of the Indian shrimp, Fenneropeanus indicus were collected from Ukkadam market, Coimbatore, India, and they were subjected to demineralisation, deproteination, and deacetylation under different concentrations of NaOH, at varying temperatures. The derived chitosan was named as LAHT SCS (low alkali high temperature shrimp chitosan), HAHT SCS (high alkali high temperature shrimp chitosan), or HART SCS (high alkali room temperature shrimp chitosan), based on the treatment. Findings: The extracted chitosan samples were evaluated for physical characteristics such as moisture, ash content, and degree of deacetylation (DD). In addition, they were subjected to Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. The HAHT SCS sample was completely soluble in 1% acetic acid and the degree of deacetylation (DD) was higher than that of standard chitosan; the crystallinity was 71%. Therefore, the extraction method employing a higher concentration of alkali (60%) and a higher deacetylation temperature (120◦C) for a long duration enhanced the solubility, conferred a higher DD (>70%), a higher crystallinity index (>60%), and less amount of ash content; all these indicate the higher quality of the sample. Among the three samples, HAHT SCS is promising for pharmaceutical and other medical applications. Novelty: The extraction of good quality chitosan from the Indian shrimp wastes was standardized. The chitosan has medicinal and industrial applications. In addition, this would reduce the pollution from improperly discarded shrimp wastes. Keywords: CrI; Chitosan; Chitin; Shrimp; Degree of deacetylation; X-ray diffraction; Fourier transform infrared spectroscopy