Crab Chitosan Research Articles

Evaluation of α-Chitosan from Crab Shell and β-Chitosan from Squid Gladius Based on Biochemistry Performance

The objective of this study is to innovatively evaluate the biochemistry performance of α-chitosan from Portunus trituberculatus shell and β-chitosan from Illex argentinus squid gladius by using the weighted composite index method, and provide a theoretical basis for better development and utilization of chitosan biomedical materials. To build a composite evaluation system, seven key indicators, including molecular weight (Mw), deacetylation degree (DD), water binding capacity (WBC), fat binding capacity (FBC), thermal stability (TS), primary structure and secondary structure, which significantly affect chitosan biochemical characteristics, were determined and analyzed. The viscosity average Mw of chitosan was in the range of 22.5–377.1 kDa, and the DD was 83.4–97.8%. Thermogravimetric (TG) and differential scanning calorimetry (DSC) analyses of commercial chitosan (CS), crab chitosan (CSC) and squid chitosan (CSS) showed a downward trend in TS, while WBC and FBC showed an obvious upward trend. FT-IR had a similar profile in peak shape, but the peak position slightly shifted. CD indicated that chitosan maintained the double helix structure and multiple secondary structural elements. The composite weighted index values of CS, CSC and CSS were 0.85, 0.94 and 1.31 respectively, which indicated that the CSS biochemistry performance was significantly better than CSC, and β-chitosan has great potential in biomedical materials.

Conception of active food packaging films based on crab chitosan and gelatin enriched with crustacean protein hydrolysates with improved functional and biological properties

This study aims to assess the effect of shrimp and crab protein hydrolysates (SPH and CPH) on structure, physicochemical, antioxidant and antimicrobial properties of composite films based on chitosan and fish gelatin. To this end, protein hydrolysates as bioactive additives were incorporated into edible films at different weight ratios 1.5, 3 and 6% (g/100 g polymer). SPH and CPH enriched films were colored and exhibited higher UV-barrier properties compared to the control chitosan-gelatin film. In addition, an improvement in the mechanical properties and thermal degradation temperatures was also observed with PHs incorporation. Furthermore, the hydrophobicity of the composite films was evaluated by determining the contact angle using different solvents (water, ethylene glycol and diiodomethane) during 120 s. With the PHs incorporation, a significant decrease, which was dependent on time and film composition, in the contact angle was found for the composite films. However, an increase in the surface wettability (especially polar component and surface tension) was observed for enriched films. Therefore, PHs addition increases the hydrophilicity of CS-gelatin based films. Interestingly, the composite films, evaluated by several in vitro assays, displayed higher antibacterial and antioxidant potential than control film. Consequently, composite films are promising alternative for active packaging to hinder food oxidation.

Experimental study on performance and influencing factors of chitosan-based nonwoven on gaseous HCHO removal

Chitosan is considered as one of the eco-friendly absorbents for HCHO removal, and its fibrous material possesses great application value in the domain of indoor air treatment. Herein, chitosan nonwoven (CSNW) and prepared chitosan-coated polypropylene nonwoven (CS-PPNW) were used to investigate the performance on dynamic HCHO purification in a one-pass air duct system. The impacts of exterior environmental parameters containing relative humidity and initial concentration on purification efficiency were assessed by CSNW at dynamic condition, while the other two interior factors including raw material and acid-pretreatment pH were both at dynamic and static condition for validation. Results indicated that the snow crab chitosan outperformed red crab in HCHO purification due to the higher amino content in molecule. The protonation of amino groups was found the reason for the deterioration of adsorptive capacity at low pH situation. And the optimum pH value was approximately 6, where the purification efficiency reached to 89.6% in static adsorption while 34.8% at dynamic condition. As the relative humidity and HCHO concentration ascends, the one-pass purification efficiency exhibits a near quadratic and exponential increase, respectively. The prepared CS-PPNW was characterized by SEM and FTIR analysis, which ascertained the adhesion of chitosan on the PP substrate. Despite lower utilization of chitosan, CS-PPNW revealed prominent capacity of HCHO removal at a loading amount of 292 g/m2 or higher. Additionally, the robust resistance properties of CSNW and CS-PPNW at filtration velocities ranging from 0.05 to 0.2 m/s also suggested the potential applicability of chitosan-based nonwoven in air purification applications.

Pengaruh Penambahan Edible Coating Kitosan Rajungan (Portunus pelagicus) Terhadap Sensori Dodol Betawi

Tujuan penelitian ingin mengetahui pengaruh edible coating dari kitosan rajungan terhadap mutu sensori dodol Betawi. Alur proses pembuatan edible coating kitosan rajungan dimulai dari pencampuran kitosan, asam asetat 1%, dan gliserol, pencelupan dodol ke dalam larutan edible coating, dan penyimpanan. Edible coating dengan konsentrasi kitosan 4% (K3) dapat mempertahankan nilai kenampakan dan tekstur sampai hari ke-12 dan aroma sampai hari ke-16, lebih lama dibanding perlakuan K0 dan K1 hanya dapat mempertahankan nilai kenampakan dan tekstur sampai hari ke-4 dan aroma sampai hari ke-8 dan K2 yang dapat mempertahankan nilai kenampakan dan tekstur sampai hari ke-8 dan aroma sampai hari ke-12 serta tidak ada perbedaan pada nilai rasa di tiga perlakuan. Berdasarkan uji Friedman parameter kenampakan, aroma, dan tekstur memiliki nilai sig.<0,05 sehingga H1 diterima dan H0 ditolak yang berarti perbedaan konsentrasi kitosan memberikan pengaruh signifikan. Sedangkan uji Friedman rasa memiliki nilai sig.>0,05 sehingga H0 diterima dan H1 ditolak yang berarti perbedaan konsentrasi kitosan tidak memberikan pengaruh signifikan.

Development of delivery system based on marine chitosan: Encapsulationand release kinetic study of antioxidant peptides from chitosan microparticle

The present work aims to encapsulate goby fish protein hydrolysate (GPH), endowed with antioxidant activity, through ionic gelation process using blue crab chitosan (CH) and tripolyphosphate anions and to evaluate the structural, thermal and antioxidant properties of the elaborated microparticles (MPs). The GPH-loaded MPs present spherical shape as seen by scanning electron microscopy (SEM) images and positive zeta potential. The increase of loaded GPH concentration led to the increase of encapsulation efficiency (EE) and to the reduction of the particle size. In fact, MPs, loaded with 2 and 5 mg/ml GPH, had EE values of 44 and 58% and mean particles size of 4.81 and 3.78 μm, respectively. Furthermore, thermogravimetric analysis (TGA) profiles revealed the enhanced thermal stability of encapsulated biopeptides compared to the free ones. Release kinetic data showed a Fickian diffusion behavior which follows swelling and a diffusion-controlled mechanism for peptides liberation. Finally, as opposed to unloaded MPs, an improvement of the antioxidant activity of the loaded MPs with biopeptides was observed.

Structural Characterization and Antioxidant Potential of Chitosan by γ-Irradiation from the Carapace of Horseshoe Crab.

Natural product extraction is ingenuity that permits the mass manufacturing of specific products in a cost-effective manner. With the aim of obtaining an alternative chitosan supply, the carapace of dead horseshoe crabs seemed feasible. This sparked an investigation of the structural changes and antioxidant capacity of horseshoe crab chitosan (HCH) by γ-irradiation using 60Co source. Chitosan was extracted from the horseshoe crab (Tachypleus gigas; Müller) carapace using heterogeneous chemical N-deacetylation of chitin, followed by the irradiation of HCH using 60Co at a dose-dependent rate of 10 kGy/hour. The average molecular weight was determined by the viscosimetric method. Regarding the chemical properties, the crystal-like structures obtained from γ-irradiated chitosan powders were determined using Fourier transfer infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses. The change in chitosan structure was evident with dose-dependent rates between 10 and 20 kGy/hour. The antioxidant properties of horseshoe crab-derived chitosan were evaluated in vitro. The 20 kGy γ-irradiation applied to chitosan changed the structure and reduced the molecular weight, providing sufficient degradation for an increase in antioxidant activity. Our findings indicate that horseshoe crab chitosan can be employed for both scald-wound healing and long-term food preservation due to its buffer-like and radical ion scavenging ability.

Structural features, anti-coagulant and anti-adhesive potentials of blue crab (Portunus segnis) chitosan derivatives: Study of the effects of acetylation degree and molecular weight

The present study was undertaken to establish a distinct relationship between blue crab chitosan (Cs) acetylation degree (AD) and molecular weight (Mw) and its structural features, thermal properties and bioactivity. Therefore, chitosans with different AD were prepared and Cellulase was used to produce Cs derivatives with decreasing Mw. Results clearly display a decrease of the ordered structure of Cs, with the increase of AD and the decrease of Mw. Thermal stability/degradation screening disclose a greater thermal resistance for Cs with lower AD and higher Mw. The anti-adhesive potential of Cs was, additionally, studied, as function of AD and Mw. The effectiveness of Cs in preventing biofilm adhesion was strongly influenced by its AD and Mw, with the lowest inhibition values for higher AD and lower Mw. Interestingly, the effectiveness of Cs in disrupting pre-formed biofilms increased with decreasing Mw. Moreover, Cs derivatives were found to be advantageously efficient in prolonging human blood clotting times, based on data of activated partial thromboplastin time, Quick time and thrombin time assays, typically for the intrinsic coagulation pathway. Accordingly, depending on the predicted application of Cs, either in food, biomedical and pharmaceutical industries, AD and Mw are critical traits to be inevitably reflected on.

Conception of novel blue crab chitosan films crosslinked with different saccharides via the Maillard reaction with improved functional and biological properties

This work aimed to modify blue crab chitosan-based films through the Maillard reaction (MR) as a novel alternative to improve their functional and biological properties. To this end, different saccharides (glucose (aldohexose), fructose (ketohexose), xylose (aldopentose) and arabinose (aldopentose)), at different weight ratios 0.5, 1.0 and 2.0 % (g/100 g polymer), were studied, and films were heated at 90 °C for 24 h. Based on color changes and browning index measurements, the extent of MR was the highest with aldopentoses, whereas hexoses and particularly ketohexoses, exhibited a relative crosslinking rate. These findings were further reflected with an improvement in treated films mechanical properties and thermal degradation temperatures, and advantageously, barrier properties against UV light and water. In addition, the MR-modified Cs-based films antioxidant activity was interestingly enhanced with mainly aldopentoses. Consequently, MR crosslinked chitosan-based films are promising alternative for active and functional packaging able of food oxidation hindering, especially using aldopentoses.

Comparison in enantioseparation performance of chiral stationary phases prepared from chitosans of different sources and molecular weights

The aim of the present study was to compare the enantioseparation performance of chiral stationary phases (CSPs) which were derived from chitosans of different sources and molecular weights. Therefore, chitosans of shrimp and crab shells were prepared. The viscosity-average molecular weights of the chitosans both prepared from shrimp and crab shells were 2.8 × 105 and 1.4 × 105. The chitosans were isobutyrylated yielding isopropylcarbonyl chitosans which were then derivatized with 4-methylphenyl isocyanate to provide chitosan 3,6-bis(4-methylphenylcarbamate)-2-(isobutyrylamide)s. The chitosan 3,6-bis(4-methylphenylcarbamate)-2-(isobutyrylamide)s were used as chiral selectors (CSs) with which the corresponding CSPs were prepared. With the same chiral analytes and under the same mobile phase conditions, the enantioseparation capability of the CSPs was evaluated by high-performance liquid chromatography. In two CSs prepared from the same source, the one with higher molecular weight showed better enantioseparation capability; in two CSs prepared with the chitosans of the same molecular weight, the one derived from shrimp shell exhibited better performance. With regard to the two shrimp chitosan CSs, most of chiral analytes interacted more strongly with the one with lower molecular weight, and an opposite trend was found for the two crab chitosan CSs. Based on the results observed in the present study and in previous work, we believe that the influence of molecular weight on CSP enantioseparation performance is related to the substituent introduced in the CS molecule.

Conception and characterization of a multi-sensitive composite chitosan-red marine alga-polysaccharide hydrogels for insulin controlled-release

Hydrogels properties open up many possibilities for medical applications. In the present study, protein drug insulin was selected as a model drug to test the in vitro release behavior of hydrogels based on blue crab chitosan (Cs) and red marine macroalga Falkenbergia rufolanosa polysaccharide (FRP). The FRP/Cs composed hydrogels were characterized in terms of structural, morphological, thermal and antioxidant properties. Data revealed that FRP addition enhanced the water holding capacity and the water uptake percentages, as well as the textural behavior. Moreover, the prepared hydrogels are simultaneous sensitive to pH, ionic strength and temperature as demonstrated in the swelling ratio test. Additionally, hydrogels at pH 1.2 PBS underwent greater degradation, compared to samples immersed in pH 7.4 PBS. Similarly, the kinetics of insuline release, through the FRP/Cs composed hydrogels exhibited higher released amounts in acidic systems. Through this study, the prepared hydrogels provided suitable and promising microenvironment in drugs delivery.

Sorption of medical preparations by chitosan

The article provides information about sorption properties of crab chitosan in relation to Analgin, Aspirin, Quamatel, Mydocalm, Paracetamol, Tsifran and Phtalazol. Quantitative determination of medicines’ amount before and after sorption was performed by HPLC-MS method with the preliminary plotting of calibration curves. The sorption capacity of chitosan taken in different concentrations was determined. Sorption isotherms and kinetic curves of medications’ sorption by chitosan were plotted. It has been shown that the maximum degree of sorption in static conditions for all studied medicines was achieved within an hour after the beginning of the sorption process.

Mathematical modeling and stimulation of thermodynamic parameters for the removal for Cr6+ from wastewater using chitosan cross-linked glutaraldehyde adsorbent

The presence of heavy metals such as chromium within water sources are considered as one of the most vital problem to the environment. Accumulating of chromium within the human body, can cause various diseases and disorders. Chitosan cross-linked glutaraldehyde adsorbent (formed from the acetyl group of chitin from alkaline solution) is widely a well-known adsorbent fore chromium metal removal present in solution. In the current study, mathematical modelling and the stimulation of thermodynamic parameters were done on crab chitosan cross-linked glutaraldehyde adsorbent for chromium (VI), Cr6+ removal. This was obtained through the prepared dichromate wastewater solution of 0.81 mg/L of Cr6+ per litre of distilled water. Adsorption experiments were also conducted in a bath system and the effect of stirring speed, chitosan cross-linked glutarladehyde dosages, contact time and temperature on the adsorption of Cr6+ were in investigated. The effectiveness of the cross-linked adsorbent at an optimum dosage (0.16 mg/L) for Cr6+) removal, from wastewater solution which was 82.3% of the initial concentration (0.81 mg/L) was found to be 0.8 g at 30 °C. The time required for the latter adsorption process to attain equilibrium was 80 min. For the thermodynamic study of the process of adsorption, properties such as Gibbs free energy (ΔGads), entropy (ΔSads) and enthalpy (ΔHads) values in the temperature ranges from 25 to 65 °C were also calculated in order to characterize the process. The free sorption energy was −47.56 kJ/mol which suggests the process was physical. The enthalpy of adsorption was −18.09 kJ/mol and the Gibbs free energies were all negative, thus the process was spontaneous and exothermic. The observed results in the current study indicated strange behavior that could not be depicted using the classical decay mathematical model. We concluded that only fractional differential operators with different kernels including the exponential decay, the power law and the generalized Mittag-Leffler function could be used to depict such observations.

Preparation and Characterization of Chitosan Membranes from Crab Shells (Scylla olivacea) for Beverage Preservative

Chitosan can extend the shelf life of food and can be used in food preservation. Chitosan is derived from the shell of the animal crustacean, and is a derivative of the chitin polymer. This study aimed to determine the effectiveness of the use of chitosan membrane as an antibacterial compound and its application in pineapple juice products. Chitosan isolation is carried out through three stages, namely deproteination, demineralization, and deacetylation. Determination of the degree of deacetylation using the infrared spectroscopy method and the preservative effectiveness test was carried out based on SNI 01-2332.3-2006 concerning the testing of the Total Plate Count (ALT). Crab chitosan obtained from white-brown isolation results, soluble in 1% acetic acid and the value of the degree of deacetylation (DD) of chitosan crab is 81%. The addition of 1.5% crab chitosan membrane to pineapple juice can reduce bacterial growth until the 20th day with a total plate value (ALT) of 9.1x103 CFU / ml.

Bioinspired pH-sensitive riboflavin controlled-release alkaline hydrogels based on blue crab chitosan: Study of the effect of polymer characteristics

Recently, the application of natural biocompatible polymeric hydrogels for the conception of drug delivery matrices has attracted widespread interest. Thus, in the present study, riboflavin pH-sensitive drug delivery hydrogels were developed based on blue crab chitosan (Cs), via direct dissolution in alkali/urea aqueous solution at low temperatures. First, the effect of Cs characteristics in terms of acetylation degree (AD) and molecular weight (Mw) on the structural, mechanical, thermal, swelling and in vitro biodegradation of Cs-based hydrogels were studied. Data from overall analysis revealed that Cs with low AD and high Mw exhibited improved mechanical properties, as evidenced by the compressive and rheological behaviors tests, thermal resistance, swelling behavior and in vitro degradation kinetics. However, hydrogels pore sizes were reduced with the AD decrease and Mw increase. Additionally, hydrogels in PBS (pH 5.5) underwent quicker degradation, compared to those immersed in PBS (pH 7.4). In the drug delivery model, the kinetics of Riboflavin release, through the Cs-based hydrogels were monitored. The Riboflavin release exhibited typical deliverance patterns, with significantly higher released amounts in more acidic systems. Therefore, drug encapsulation within the conceived pH-sensitive Cs-based hydrogels could provide suitable and promoting microenvironment for drugs delivery.

Design of blue crab chitosan responsive nanoparticles as controlled-release nanocarrier: Physicochemical features, thermal stability and in vitro pH-dependent delivery properties

In this study, carotenoproteins (CPs) were encapsulated in blue crab chitosan-tripolyphosphate and chitosan-protein isolate nanoparticles by ionotropic gelation and complex coacervation, respectively. The success of CPs encapsulation was confirmed by FT-IR spectroscopy, TGA and XRD techniques. Particles size and thermal stability of nanoparticles depend on the encapsulation method. Indeed, a regular distribution and spherical shape, with size range of about 300 nm (ionotropic gelation) – 600 nm (complex coacervation), were observed by SEM analysis. The encapsulation efficiency and loading capacity of CPs were about 74% and 31% for the complex coacervation and 89% and 47% for the ionotropic gelation approaches, respectively. In vitro release studies showed a fast initial release effect, followed by a slow CPs release. The highest amount of released CPs in a shorter time was observed with the ionotropic gelation method. Further, in vitro release kinetics of CPs were found to be medium dependent, where nanoparticles incubated in ethanol displayed higher released CPs amount in a longer release time, compared to nanoparticles immerged in PBS (pH ~ 6.8). These findings suggest that the encapsulation technique obviously affected the particles structure, and the glass transition temperature, and the mass loss of encapsulated materials. The better CPs thermal stabilization was obtained for the ionotropic gelation nanoparticles.

Daya Antibakteri Kitosan Kepiting Rajungan (Portunus Pelagicus) Terhadap Biofilm Porphyromonas Gingivalis

Background: Porphyromonas gingivalis bacteria are found in dental plaques and have the ability to form biofilms. Biofilms are collections of bacterial cells, which are tightly attached to a surface covered by an extracellular polymer matrix released by the bacteria. Periodontitis therapy generally uses tetracycline antibiotics which if used long-term can cause resistance. Chitosan Rajungan crab extract (Portunus pelagicus) has antimicrobial potential which can be used as an alternative therapy. Objective: To determine the antibacterial power of Rajungan crab chitosan extract (Portunus pelagicus) in various concentrations of Porphyromonas gingivalis bacterial biofilms. Method: This research was true experimental laboratorist . This study used Rajungan crab chitosan extract (Portunus pelagicus) to Porphyromonas gingivalis biofilm tested by the test method biofilm. Divided into 5 groups, where each group consisted of 4 samples. The control group consisted of: K- (negative control group), K + (positive control group / tetracycline group), and 3 treatment groups, namely P1 (0.25% Rajungan crab chitosan), P2 (0.5% Rajungan crab chitosan) , P3 (1% Rajungan crab chitosan). Antibacterial power was determined by the value of Optical density in the ELISA Reader. Data analysis using One Way ANOVA followed by LSD test. Result: There were significant differences (p <0.05) seen from the percentage of biofilm inhibition in the negative control group for all groups, the positive control group for the crab crab chitosan extract concentrations of 0.25% and 0.5%. Conclusion: The chitosan crab chitosan extract (Portunus pelagicus) with 1% concentration has the greatest antibacterial effect on the Porphyromonas gingivalis biofilm

Investigation of the properties of N-[(2-hydroxy-3-trimethylammonium) propyl] chloride chitosan derivatives

N-[(2-Hydroxy-3-Trimethylammonium) Propyl] Chitosan Chloride Derivatives (HTCC), based on low molecular weight crab chitosan, were synthesized by the alkylation reaction with a degree of substitution of 10–98%. The chemical structure was confirmed by 1H NMR and IR-spectra. Physical and chemical characteristics and a number of properties were defined. All HTCC derivatives were soluble at pH 7.4. HTCCs have an inhibitory capacity on the growth of the studied microorganisms. The introduction of quaternary ammonium groups into chitosan molecule contributed to the increase of antibacterial activity of derivatives. HTCC53 showed antifungal activity and at a concentration of 500 mg/ml completely inhibited the growth of mycelial fungi F. oxysporum, A. alternata and C. herbarum. When studying the ability of HTCCs to absorb DPPH radicals, it was found that samples of HTCC10 and HTCC40 showed high inhibitory capacity at a concentration of >15 mg/ml. It was shown that the chelating ability of HTCCs decreased by reducing the number of free amino groups. HTCC10-HTCC53 demonstrated the maximum values of chelating ability at a concentration of 4–10 mg/ml. Due to the solubility at neutral pH values and the properties shown, obtained chitosan derivatives can be used in clinical practice, pharmaceutical and food industries in the future.

Acetylation degree, a key parameter modulating chitosan rheological, thermal and film-forming properties

The effect of blue crab chitosan acetylation degree (AD) on its rheological, thermal and film-forming properties was investigated. Determination of the dynamic viscoelastic properties (elastic modulus G’ and viscous modulus G”) of chitosan solutions revealed a typical Newtonian viscous-like behavior, with higher viscosity values at lower acetylation degrees. Moreover, the gelation temperature of blue crab chitosan was strongly dependent on its acetylation degree, with lower values at lower acetylation degrees. Regarding chitosan thermal stability, thermogravimetric profiles revealed greater thermal resistance for chitosans with lower acetylation degrees, showing significantly higher degradation temperature. Likewise, the values of glass transition temperature decreased with the increase of the acetylation degree. In another side, chitosan-based films, with lower acetylation degrees, are found to be more flexible, resistant and transparent. Therefore, blue crab chitosan acetylation degree modulated toughly its viscosity, elongation at break, tensile strength and thermal resistance. Further, chitosans with ADs less than 20% seemed to have potential industrial applications.

Anti-biofilm Activity of Chitosan from Crab and Shrimp Species Indigenous to the Philippines on Established Biofilms of Pseudomonas aeruginosa and Staphylococcus aureus

Biofilms are structures produced by bacteria by attaching themselves together in a surface to form a protective matrix, rendering them resistant to antimicrobial treatments. The objective of this study was to examine the anti-biofilm activity of chitosan from crab and shrimp species on the established biofilms of Pseudomonas aeruginosa and Staphylococcus aureus. The test groups were treated with chitosan solutions of varying concentrations (2.5 g/L and 10 g/L) chitosan from shrimp shells extract, 2.5 g/L and 10 g/L crab shells extract and a mixture of both shell extracts with the same concentration mixed in a one-to-one volume by ratio. Three different analysis were conducted involving color intensity test through TotalLab software, spectrophotometric analysis and microplate reader analysis. The highest percent anti-biofilm formation inhibition was observed with the 2.5 g/L mixed (1:1) chitosan solution against established biofilms of P. aeruginosa with a 62.90 ± 12% inhibition. On the other hand, S. aureus showed no percent inhibition with the 2.5 g/L shrimp chitosan and 10 g/L crab chitosan but was most sensitive to 10 g/L mixed (1:1) chitosan solution with an inhibition of 39.47 ± 19%. From the results, the 1:1 combination of shrimp and crab chitosan solutions resulted to a higher percent anti-biofilm formation inhibition than when given separately.

Development of a controlled bioconversion process for the recovery of chitosan from blue crab (Portunus segnis) exoskeleton

The present work aimed to extract chitin and chitosan from blue crab (Portunus segnis) shells, via an optimized procedure keeping as much as possible its native structure. Thus, several microbial, visceral and commercial proteases were tested for their deproteinization efficiency. High levels of protein removal of about 82% and 85% were recorded using Bacillus safensis proteases and crude enzyme extract of P. segnis, respectively. Further, 0.5 M HCl baths based system was adopted for minerals removal. Blue crab chitin had the following characteristics: acetylation degree of 97%, deproteinization and demineralization rates of 92% and 100%, respectively. Subsequently, blue crab chitosan (BCC) was prepared by chitin N-deacetylation, leading to an acetylation degree of 10%. After characterization by FTIR spectroscopy and X-ray diffraction, the functional properties and antioxidant and antimicrobial activities of BCC were investigated. Interestingly, BCC exhibited notable in vitro antioxidant activity including DPPH and hydroxyl radicals scavenging, β-carotene bleaching inhibition and metal chelating effects (92%, 89%, 72%, and 93%, at 5 mg/ml, respectively). Moreover, chitosan markedly inhibited growth and adhesion of all microorganisms tested, and was efficient in the disruption of pre-formed biofilms.