Displaying publications 1 - 20 of 195 in total

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  1. Zokti JA, Sham Baharin B, Mohammed AS, Abas F
    Molecules, 2016 Jul 26;21(8).
    PMID: 27472310 DOI: 10.3390/molecules21080940
    Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE). To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD), gum arabic (GA) and chitosan (CTS) and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%-88.04%, 19.32-24.90 (g GAE/100 g), and 29.52%-38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%-5.11%, 0.28-0.36, 3.22%-4.71%, 0.22-0.28 g/cm³ and 40.43-225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was determined as 142.00%-188.63% and 207.55%-231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC) and antioxidant activity did not decrease significantly (p ≥ 0.05) under 4 °C storage conditions. The half-life study results were in the range of 35-60, 34-65 and 231-288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.
    Matched MeSH terms: Chitosan/chemistry
  2. Zhu P, Huang G, Zhang B, Zhang W, Dang M, Huang Z
    Acta Biochim. Pol., 2019 Mar 11;66(1):71-76.
    PMID: 30856636 DOI: 10.18388/abp.2018_2719
    Bone fracture, being mainly caused by mechanical stress, requires special and quick attention for a rapid healing. The study presented here aims at formulating nanoparticulate system to overcome the solubility issues of lovastatin. The lovastatin nanoparticles were successfully prepared by ionotropic gelation method using chitosan and tri-polyphosphate as polymers. Thus prepared nanoparticles were found to be smooth and spherical with average particle size of 87 nm and encapsulation efficiency of 86.5%. The in-vitro drug release was found to be almost 89.6% in the first 360 minutes. Artificial fracture was produced in female Wistar rats at right leg using fracture apparatus. After administration of lovastatin nanoparticles or saline solution, the respective groups were observed for various parameters. The X-ray imaging showed that lovastatin accelerated bone healing, compared to control. The growth of animals was not hampered by lovastatin by any means. The radiographic examination confirmed a role of lovastatin in increasing bone density. The histological study showed the broken, proliferated and discontinued trabecullae in the control, while at the same time point, the normal, thick, continuous and connected trabecullae were observed in animals administered with lovastatin nanoparticles. The biomechanical studies showed high breaking resilience and minimum bone brittleness in animals injected with lovastatin nanoparticles. Considering these observations we state that lovastatin helps in rapid bone healing after fracture via increasing the bone density.
    Matched MeSH terms: Chitosan/chemistry*
  3. Zeimaran E, Pourshahrestani S, Pingguan-Murphy B, Kong D, Naveen SV, Kamarul T, et al.
    Carbohydr Polym, 2017 Nov 01;175:618-627.
    PMID: 28917909 DOI: 10.1016/j.carbpol.2017.08.038
    Blends of poly (1, 8-octanediol citrate) (POC) and chitosan (CS) were prepared through solution casting technique. Films with different component fractions (POC/CS: 100/0, 90/10, 80/20, 70/30, 60/40, and 0/100) were successfully prepared and characterized for their mechanical, thermal, structural and morphological properties as well as biocompatibility. The incorporation of CS to POC significantly increased tensile strength and elastic modulus and presented limited influences on pH variation which is important to the biocompatibility of biomaterial implants. The assessment of surface topography indicated that blending could enhance and control the surface roughness of the pure films. POC/CS blends well-supported human dermal fibroblast cells attachment and proliferation, and thus can be used for a range of tissue engineering applications.
    Matched MeSH terms: Chitosan/chemistry*
  4. Zainal Z, Hui LK, Hussein MZ, Abdullah AH, Hamadneh IM
    J Hazard Mater, 2009 May 15;164(1):138-45.
    PMID: 18809254 DOI: 10.1016/j.jhazmat.2008.07.154
    In this paper, the newly explored TiO(2)-Chitosan/Glass was suggested as a promising alternative material to conventional means of wastewater treatment. Characterization of TiO(2)-Chitosan/Glass photocatalyst was studied with SEM-EDX, XRD, and Fourier transform infrared spectroscopy (FTIR) analysis. The combination effect of photodegradation-adsorption process for the removal of methyl orange (MO), an acid dye of the monoazo series occur promisingly when four layers of TiO(2)-Chitosan/Glass photocatalyst was used for MO removal. Approximately, 87.0% of total MO removal was achieved. The reactive -NH(2), -OH, and metal oxide contents in the prepared photocatalyst responsible for the photodegradation-adsorption effect were confirmed by FTIR study. Similarly, MO removal behavior was well supported by SEM-EDX and XRD analysis. Significant dependence of MO removal on the TiO(2)-Chitosan loading can be explained in terms of relationship between quantum yield of photocatalytic reactions and photocatalyst structure/activity. Hence, the research work done thus far suggests a new method, having both the advantages of photodegradation-adsorption process in the abatement of various wastewater pollutants.
    Matched MeSH terms: Chitosan/chemistry*
  5. Zain NM, Stapley AG, Shama G
    Carbohydr Polym, 2014 Nov 4;112:195-202.
    PMID: 25129735 DOI: 10.1016/j.carbpol.2014.05.081
    Silver and copper nanoparticles were produced by chemical reduction of their respective nitrates by ascorbic acid in the presence of chitosan using microwave heating. Particle size was shown to increase by increasing the concentration of nitrate and reducing the chitosan concentration. Surface zeta potentials were positive for all nanoparticles produced and these varied from 27.8 to 33.8 mV. Antibacterial activities of Ag, Cu, mixtures of Ag and Cu, and Ag/Cu bimetallic nanoparticles were tested using Bacillus subtilis and Escherichia coli. Of the two, B. subtilis proved more susceptible under all conditions investigated. Silver nanoparticles displayed higher activity than copper nanoparticles and mixtures of nanoparticles of the same mean particle size. However when compared on an equal concentration basis Cu nanoparticles proved more lethal to the bacteria due to a higher surface area. The highest antibacterial activity was obtained with bimetallic Ag/Cu nanoparticles with minimum inhibitory concentrations (MIC) of 0.054 and 0.076 mg/L against B. subtilis and E. coli, respectively.
    Matched MeSH terms: Chitosan/chemistry*
  6. Yusof NH, Foo KY, Hameed BH, Hussin MH, Lee HK, Sabar S
    Int J Biol Macromol, 2020 Aug 15;157:648-658.
    PMID: 31790734 DOI: 10.1016/j.ijbiomac.2019.11.218
    Chitosan-polyethyleneimine with calcium chloride as ionic cross-linker (CsPC) was synthesized as a new kind of adsorbent using a simple, green and cost-effective technique. The adsorption properties of the adsorbent for Acid Red 88 (AR88) dye, as a model analyte, were investigated in a batch system as the function of solution pH (pH 3-12), initial AR88 concentration (50-500 mg L-1), contact time (0-24 h), and temperature (30-50 °C). Results showed that the adsorption process obeyed the pseudo-first order kinetic model and the adsorption rate was governed by both intra-particle and liquid-film mechanism. Equilibrium data were well correlated with the Freundlich isotherm model, with the calculated maximum adsorption capacity (qm) of 1000 mg g-1 at 30 °C. The findings underlined CsPC to be an effective and efficient adsorbent, which can be easily synthesized via one-step process with promising prospects for the removal of AR88 or any other similar dyes from the aqueous solutions.
    Matched MeSH terms: Chitosan/chemistry*
  7. Yong SK, Skinner WM, Bolan NS, Lombi E, Kunhikrishnan A, Ok YS
    Environ Sci Pollut Res Int, 2016 Jan;23(2):1050-9.
    PMID: 26538256 DOI: 10.1007/s11356-015-5654-5
    Pristine chitosan beads were modified with sulfur (S)-containing functional groups to produce thiolated chitosan beads (ETB), thereby increasing S donor ligands and crosslinks. The effect of temperature, heating time, carbon disulfide (CS2)/chitosan ratio, and pH on total S content of ETB was examined using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The total S content of ETB increased with increasing CS2/chitosan ratio and decreased with decreasing pH and increasing temperature (>60 °C) and heating time (at 60 °C). Spectroscopic analyses revealed the presence of thiol (-SH)/thione, disulfide (-S-S-), and sulfonate groups in ETB. The thiolation mechanism involves decomposition of dithiocarbamate groups, thereby forming thiourea crosslinks and trithiocarbonate, resulting in -SH oxidation to produce -S-S- crosslinks. The partially formed ETB crosslinks contribute to its acid stability and are thermodynamically feasible in adsorbing Cd and Cu. The S-containing functional groups added to chitinous wastes act as sorbents for metal remediation from acidic environments.
    Matched MeSH terms: Chitosan/chemistry*
  8. Xu FX, Ooi CW, Liu BL, Song CP, Chiu CY, Wang CY, et al.
    Int J Biol Macromol, 2021 Jun 30;181:508-520.
    PMID: 33775766 DOI: 10.1016/j.ijbiomac.2021.03.151
    This study aimed to develop a novel electrospun polyacrylonitrile (PAN) nanofiber membrane with the enhanced antibacterial property. The PAN nanofiber membrane was first subjected to alkaline hydrolysis treatment, and the treated membrane was subsequently grafted with chitosan (CS) to obtain a CS-modified nanofiber membrane (P-COOH-CS). The modified membrane was then coupled with different dye molecules to form P-COOH-CS-Dye membranes. Lastly, poly(hexamethylene biguanide) hydrochloride (PHMB) was immobilized on the modified membrane to produce P-COOH-CS-Dye-PHMB. Physical characterization studies were conducted on all the synthesized nanofiber membranes. The antibacterial efficacies of nanofiber membranes prepared under different synthesis conditions were evaluated systematically. Under the optimum synthesis conditions, P-COOH-CS-Dye-PHMB was highly effective in disinfecting a high concentration of Escherichia coli, with an antibacterial efficacy of approximately 100%. Additionally, the P-COOH-CS-Dye-PHMB exhibited an outstanding wash durability as its antibacterial efficacy was only reduced in the range of 5%-7% even after 5 repeated cycles of treatment. Overall, the experimental results of this study suggested that the P-COOH-CS-Dye-PHMB is a promising antibacterial nanofiber membrane that can be adopted in the food, pharmaceutical, and textile industries.
    Matched MeSH terms: Chitosan/chemistry*
  9. Wu JY, Ooi CW, Song CP, Wang CY, Liu BL, Lin GY, et al.
    Carbohydr Polym, 2021 Jun 15;262:117910.
    PMID: 33838797 DOI: 10.1016/j.carbpol.2021.117910
    N-[(2-hydroxyl-3-trimethylammonium) propyl] chitosan chloride (HTCC), which is a type of chitosan derivative with quaternary ammonium groups, possesses a higher antibacterial activity as compared to the pristine chitosan. The nanofiber membranes made of HTCC are attractive for applications demanding for antibacterial function. However, the hydrophilic nature of HTCC makes it unsuitable for electrospinning of nanofibers. Hence, biodegradable polyvinyl alcohol (PVA) was proposed as an additive to improve the electrospinnability of HTCC. In this work, PVA/HTCC nanofiber membrane was crosslinked with the blocked diisocyanate (BI) to enhance the stability of nanofiber membrane in water. Microbiological assessments showed that the PVA/HTCC/BI nanofiber membranes possessed a good antibacterial efficacy (∼100 %) against E. coli. Moreover, the biocompatibility of PVA/HTCC/BI nanofiber membrane was proven by the cytotoxicity test on mouse fibroblasts. These promising results indicated that the PVA/HTCC/BI nanofiber membrane can be a promising material for food packaging and as a potential wound dressing for skin regeneration.
    Matched MeSH terms: Chitosan/chemistry*
  10. Wong TW
    Recent Pat Drug Deliv Formul, 2009 Jan;3(1):8-25.
    PMID: 19149726 DOI: 10.2174/187221109787158346
    The global burden of diabetes is estimated to escalate from about 171 million in 2000 to 366 million people in 2030. The routine of diabetes treatment by injection of insulin incurs pain and has been one major factor negating the quality of life of diabetic patients. The possibility of administering insulin via alternative routes such as oral and nasal pathways has been investigated over the years, but with insulin experiencing risks of enzymatic degradation and poor transmucosal absorption. This leads to the rising needs to develop new formulation strategies emphasizing on the assembly of insulin and excipients into a physical structure to maintain the stability and increase the bioavailability of insulin. Chitosan and its derivatives or salts have been widely investigated as functional excipients of delivering insulin via oral, nasal and transdermal routes. The overview of various recent patented strategies on non-injection insulin delivery denotes the significance of chitosan for its mucoadhesive and able to protect the insulin from enzymatic degradation, prolong the retention time of insulin, as well as, open the inter-epithelial tight junction to facilitate systemic insulin transport. The chitosan can be employed to strengthen the physicochemical stability of insulin and multi-particulate matrix. The introduction of chitosan coat or co-formulation of chitosan with cationic gelatin or electrolytes which provide solidified or partially crosslinked structures retain and/or enhance the positive charges of dosage form necessary to induce mucoadhesiveness. The chitosan is modifiable chemically to produce water-soluble low molecular weight polymer which renders insulin able to be processed under mild conditions, and sulphated chitosan which markedly opens the paracellular channels for insulin transport. Combination of chitosan and fatty acid as hydrophobic nanoparticles promotes the insulin absorption via lymphoid tissue. Attainment of optimized formulations with higher levels of pharmacological bioavailability is deemed possible in future through targeted delivery of insulin using chitosan with specific adhesiveness to the intended absorption mucosa.
    Matched MeSH terms: Chitosan/chemistry*
  11. Wong TW, Nurjaya S
    Eur J Pharm Biopharm, 2008 May;69(1):176-88.
    PMID: 17980563
    The effects of microwave irradiation on the drug release property of pectinate beads loaded internally with chitosan (chitosan-pectinate beads) were investigated against the pectinate beads and beads coacervated with chitosan externally (pectinate-chitosonium beads). These beads were prepared by an extrusion method using sodium diclofenac as the model water-soluble drug. The beads were subjected to microwave irradiation at 80 W for 5, 10, 21 and 40 min. The profiles of drug dissolution, drug content, drug-polymer interaction and polymer-polymer interaction were determined by drug dissolution testing, drug content assay, drug adsorption study, differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR) techniques. Treatment of pectinate beads by microwave did not lead to a decrease, but an increase in the extent of drug released at 4h of dissolution owing to reduced pectin-pectin interaction via the CO moiety of polymer. In addition, the extent of drug released from the pectinate beads could not be reduced merely through the coacervation of pectinate matrix with chitosan. The reduction in the extent of drug released from the pectinate-chitosonium beads required the treatment of these beads by microwave, following an increase in drug-polymer and polymer-polymer interaction in the matrix. The extent of drug released from the pectinate beads was reduced through incorporating chitosan directly into the interior of pectinate matrix, owing to drug-chitosan adsorption. Nonetheless, the treatment of chitosan-pectinate matrix by microwave brought about an increase in the extent of drug released unlike those of pectinate-chitosonium beads. Apparently, the loading of chitosan into the interior of pectinate matrix could effectively retard the drug release without subjecting the beads to the treatment of microwave. The microwave was merely essential to reduce the release of drug from pectinate beads when the chitosan was introduced to the pectinate matrix by means of coacervation. Under the influences of microwave, the drug release property of beads made of pectin and chitosan was mainly modulated via the CH, OH and NH moieties of polymers and drug, with CH functional group purported to retard while OH and NH moieties purported to enhance the drug released from the matrix.
    Matched MeSH terms: Chitosan/chemistry*
  12. Wong TW, Chan LW, Kho SB, Heng PW
    J Control Release, 2005 Jun 2;104(3):461-75.
    PMID: 15911046
    The influence of microwave irradiation on the drug release properties of freshly prepared and aged alginate, alginate-chitosan and chitosan beads was investigated. The beads were prepared by extrusion method with sulphathiazole as a model drug. The dried beads were subjected to microwave irradiation at 80 W for 10 min, 20 min or three consecutive cycles of 10 and 20 min, respectively. The profiles of drug dissolution, drug content, drug stability, drug polymorphism, drug-polymer interaction, polymer crosslinkage and complexation were determined by dissolution testing, drug content assay, differential scanning calorimetry and Fourier transform infra-red spectroscopy. The chemical stability of drug embedded in beads was unaffected by microwave conditions and length of storage time. The release property of drug was mainly governed by the extent of polymer interaction in beads. The aged alginate beads required intermittent cycles of microwave irradiation to induce drug release retarding effect in contrast to their freshly prepared samples. Unlike the alginate beads, the level of polymer interaction was higher in aged alginate-chitosan beads than the corresponding fresh beads. The drug release retarding property of aged alginate-chitosan beads could be significantly enhanced through subjecting the beads to microwave irradiation for 10 min. No further change in drug release from these beads was observed beyond 30 min of microwave irradiation. Unlike beads containing alginate, the rate and extent of drug released from the aged chitosan beads were higher upon treatment by microwave in spite of the higher degree of polymer interaction shown by the latter on prolonged storage. The observation suggested that the response of polymer matrix to microwave irradiation in induction of drug release retarding property was largely affected by the molecular arrangement of the polymer chains.
    Matched MeSH terms: Chitosan/chemistry
  13. Wong TW, Nurulaini H
    Drug Dev Ind Pharm, 2012 Dec;38(12):1417-27.
    PMID: 22309449 DOI: 10.3109/03639045.2011.653364
    Alginate-chitosan pellets prepared by extrusion-spheronization technique exhibited fast drug dissolution.
    Matched MeSH terms: Chitosan/chemistry*
  14. Wong SHM, Lim SS, Tiong TJ, Show PL, Zaid HFM, Loh HS
    Int J Mol Sci, 2020 Jul 22;21(15).
    PMID: 32708043 DOI: 10.3390/ijms21155202
    An ideal scaffold should be biocompatible, having appropriate microstructure, excellent mechanical strength yet degrades. Chitosan exhibits most of these exceptional properties, but it is always associated with sub-optimal cytocompatibility. This study aimed to incorporate graphene oxide at wt % of 0, 2, 4, and 6 into chitosan matrix via direct blending of chitosan solution and graphene oxide, freezing, and freeze drying. Cell fixation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, alkaline phosphatase colorimetric assays were conducted to assess cell adhesion, proliferation, and early differentiation of MG63 on chitosan-graphene oxide scaffolds respectively. The presence of alkaline phosphatase, an early osteoblast differentiation marker, was further detected in chitosan-graphene oxide scaffolds using western blot. These results strongly supported that chitosan scaffolds loaded with graphene oxide at 2 wt % mediated cell adhesion, proliferation, and early differentiation due to the presence of oxygen-containing functional groups of graphene oxide. Therefore, chitosan scaffolds loaded with graphene oxide at 2 wt % showed the potential to be developed into functional bone scaffolds.
    Matched MeSH terms: Chitosan/chemistry*
  15. Winie T, Arof AK
    Spectrochim Acta A Mol Biomol Spectrosc, 2006 Mar 1;63(3):677-84.
    PMID: 16157506
    Fourier transform infrared (FT-IR) spectroscopic studies have been undertaken to investigate the interactions among components in a system of hexanoyl chitosan-lithium trifluoromethanesulfonate (LiCF(3)SO(3))-diethyl carbonate (DEC)/ethylene carbonate (EC). LiCF(3)SO(3) interacts with the hexanoyl chitosan to form a hexanoyl chitosan-salt complex that results in the shifting of the N(COR)(2), CONHR and OCOR bands to lower wavenumbers. Interactions between EC and DEC with LiCF(3)SO(3) has been noted and discussed. Evidence of interaction between EC and DEC has been obtained experimentally. Studies on polymer-plasticizer spectra suggested that there is no interaction between the polymer host and plasticizers. Competition between plasticizer and polymer on associating with Li(+) ions was observed from the spectral data for gel polymer electrolytes. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolytes.
    Matched MeSH terms: Chitosan/chemistry*
  16. Wei S, Ching YC, Chuah CH
    Carbohydr Polym, 2020 Mar 01;231:115744.
    PMID: 31888854 DOI: 10.1016/j.carbpol.2019.115744
    Chitosan with abundant functional groups is regarded as important ingredients for preparing aerogel materials in life science. The biocompatibility and biodegradability of chitosan aerogels, coupled to the variety of chemical functionalities they include, result in them promising carriers for drug delivery. Moreover, chitosan aerogels as drug delivery vehicles can offer improved drug bioavailability and drug loading capacity due to their highly porous network, considerably large specific surface area and polycationic feature. The major focus of this review lies in preparation methods of chitosan aerogels from acidic aqueous solution and chitosan solution in Ionic Liquids (ILs). In addition, chitosan aerogels as drug delivery carriers are introduced in detail and expected to inspire readers to create new kind of drug delivery system based on chitosan aerogels. Finally, growing points and perspectives of chitosan aerogels in drug delivery system are given.
    Matched MeSH terms: Chitosan/chemistry*
  17. Wan Ngah WS, Hanafiah MA, Yong SS
    Colloids Surf B Biointerfaces, 2008 Aug 1;65(1):18-24.
    PMID: 18359205 DOI: 10.1016/j.colsurfb.2008.02.007
    The adsorption of humic acid on crosslinked chitosan-epichlorohydrin (chitosan-ECH) beads was investigated. Chitosan-ECH beads were characterized by Fourier transform infrared spectroscopy (FTIR), surface area and pore size analyses, and scanning electron microscopy (SEM). Batch adsorption experiments were carried out and optimum humic acid adsorption on chitosan-ECH beads occurred at pH 6.0, agitation rate of 300 rpm and contact time of 50 min. Adsorption equilibrium isotherms were analyzed by Langmuir and Freundlich models. Freundlich model was found to show the best fit for experimental data while the maximum adsorption capacity determined from Langmuir model was 44.84 mg g(-1). The adsorption of humic acid on chitosan-ECH beads was best described with pseudo-first-order kinetic model. For desorption study, more than 60% of humic acid could be desorbed from the adsorbent using 1.0M HCl for 180 min.
    Matched MeSH terms: Chitosan/chemistry
  18. Wan Ngah WS, Kamari A, Koay YJ
    Int J Biol Macromol, 2004 Jun;34(3):155-61.
    PMID: 15225987
    The adsorption of Cu(II) ions from aqueous solution by chitosan and chitosan/PVA beads was studied in a batch adsorption system. Chitosan solution was blended with poly(vinyl alcohol) (PVA) in order to obtain sorbents that are insoluble in aqueous acidic and basic solution. The adsorption capacities and rates of Cu(II) ions onto chitosan and chitosan/PVA beads were evaluated. The Langmuir, Freundlich and BET adsorption models were applied to describe the isotherms and isotherm constants. Adsorption isothermal data could be well interpreted by the Langmuir model. The kinetic experimental data properly correlated with the second-order kinetic model, which indicates that the chemical sorption is the rate-limiting step. The Cu(II) ions can be removed from the chitosan and chitosan/PVA beads rapidly by treatment with an aqueous EDTA solution. Results also showed that chitosan and chitosan/PVA beads are favourable adsorbers.
    Matched MeSH terms: Chitosan/chemistry*
  19. Vejan P, Abdullah R, Khadiran T, Ismail S
    Lett Appl Microbiol, 2019 Jan;68(1):56-63.
    PMID: 30339728 DOI: 10.1111/lam.13088
    Sustainable crop production for a rapidly growing human population is one of the current challenges faced by the agricultural sector. However, many of the chemical agents used in agriculture can be hazardous to humans, non-targeted organism and environment. Plant growth promoting rhizobacteria have demonstrated a role in promoting plant growth and health under various stress conditions including disease. Unfortunately, bacterial viability degrades due to temperature and other environmental factors (Bashan et al., Plant Soil 378: 1-33, 2014). Encapsulation of bacteria into core-shell biopolymers is one of the promising techniques to overcome the problem. This study deals with the encapsulation of Bacillus salmalaya 139SI using simple double coating biopolymer technique which consist of brown rice protein/alginate and 0·5% low molecular weight chitosan of pH 4 and 6. The influence of biopolymer to bacteria mass ratio and the chitosan pH on the encapsulation process, physic-chemical, morphology and bioactivity properties of encapsulated B. salmalaya 139SI have been studied systematically. Based on the analysis of physico-chemical, morphology and bioactivity properties, B. salmalaya 139S1 encapsulated using double coating encapsulation technology has promising viability pre- and postfreeze-drying with excellent encapsulation yields of 99·7 and 89·3% respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The need of a simple yet effective way of encapsulating plant growth promoting rhizobacteria is crucial to further improve their benefits to global sustainable agriculture practice. Effective encapsulation allows for protection, controlled release and function of the micro-organism, as well as providing a longer shelf life for the product. This research report offers an innovative yet simple way of encapsulating using double coating technology with environmentally friendly biopolymers that could degrade and provide nutrients when in soil. Importantly, the bioactivity of the bacteria is maintained upon encapsulation.
    Matched MeSH terms: Chitosan/chemistry
  20. Vallejo-Domínguez D, Rubio-Rosas E, Aguila-Almanza E, Hernández-Cocoletzi H, Ramos-Cassellis ME, Luna-Guevara ML, et al.
    Ultrason Sonochem, 2021 Apr;72:105417.
    PMID: 33352467 DOI: 10.1016/j.ultsonch.2020.105417
    Recently, chitin and chitosan are widely investigated for food preservation and active packaging applications. Chemical, as well as biological methods, are usually adopted for the production of these biopolymers. In this study, modification to a chemical method of chitin synthesis from shrimp shells has been proposed through the application of high-frequency ultrasound. The impact of sonication time on the deproteinization step of chitin and chitosan preparation was examined. The chemical identities of chitin and chitosan were verified using infrared spectroscopy. The influence of ultrasound on the deacetylation degree, molecular weight and particle size of the biopolymer products was analysed. The microscopic characteristics, crystallinity and the colour characteristics of the as-obtained biopolymers were investigated. Application of ultrasound for the production of biopolymers reduced the protein content as well as the particle size of chitin. Chitosan of high deacetylation degree and medium molecular weight was produced through ultrasound assistance. Finally, the as-derived chitosan was applied for beef preservation. High values of luminosity, chromatid and chrome were noted for the beef samples preserved using chitosan films, which were obtained by employing biopolymer subjected to sonication for 15, 25 and 40 min. Notably; these characteristics were maintained even after ten days of packaging. The molecular weight of these samples are 73.61 KDa, 86.82 KDa and 55.66 KDa, while the deacetylation degree are 80.60%, 92.86% and 94.03%, respectively; in the same order, the particle size of chitosan are 35.70 μm, 25.51 μm and 20.10 μm.
    Matched MeSH terms: Chitosan/chemistry*
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