Next Article in Journal
The Pseudolesions of the Oral Mucosa: Differential Diagnosis and Related Systemic Conditions
Previous Article in Journal
A Simple Convolutional Neural Network with Rule Extraction
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

Chitosan Nanocomposite Coatings for Food, Paints, and Water Treatment Applications

1
Functional Materials, Department of Applied Physics, SCI School, KTH Royal Institute of Technology, SE-164 40 Kista, Stockholm, Sweden
2
Department of Food Engineering & Technology, Central Institute of Technology, Kokrajhar 783370, Assam, India
3
Department of Marine Science, Sultan Qaboos University, PO Box 34, Al Khoud, Muscat 123, Oman
4
Center of Excellence in Marine Biotechnology, Sultan Qaboos University, PO Box 50, Al Khoud, Muscat 123, Oman
*
Author to whom correspondence should be addressed.
Appl. Sci. 2019, 9(12), 2409; https://doi.org/10.3390/app9122409
Submission received: 10 May 2019 / Revised: 1 June 2019 / Accepted: 8 June 2019 / Published: 13 June 2019
(This article belongs to the Section Nanotechnology and Applied Nanosciences)

Abstract

:
Worldwide, millions of tons of crustaceans are produced every year and consumed as protein-rich seafood. However, the shells of the crustaceans and other non-edible parts constituting about half of the body mass are usually discarded as waste. These discarded crustacean shells are a prominent source of polysaccharide (chitin) and protein. Chitosan is a de-acetylated form of chitin obtained from the crustacean waste that has attracted attention for applications in food, biomedical, and paint industries due to its characteristic properties, like solubility in weak acids, film-forming ability, pH-sensitivity, biodegradability, and biocompatibility. We present an overview of the application of chitosan in composite coatings for applications in food, paint, and water treatment. In the context of food industries, the main focus is on fabrication and application of chitosan-based composite films and coatings for prolonging the post-harvest life of fruits and vegetables, whereas anti-corrosion and self-healing properties are the main properties considered for antifouling applications in paints in this review.

1. Introduction

Millions of tons of crustaceans such as shells of crabs, shrimps, lobsters, and krill are produced each year and consumed as protein-rich seafood worldwide. The shells of the crustaceans and other non-edible parts that constitute about half of the body mass, and which are a prominent source of chitin and protein, are generally discarded as waste. Though chitin is the second largest natural polysaccharide on earth, after cellulose, it is not widely used for fabrication of products or as a food commodity due its insolubility in many commonly used solvents [1,2]. Chitosan (CH) can be obtained commercially from crustaceans’ wastes and the cell walls of some fungi by the de-acetylation of chitin [3,4,5]. The United States Food and Drug Administration (USFDA) has recommended chitosan a GRAS (Generally Recognized as Safe) material, which has led to the application of chitosan in food, agriculture, and biomedicine.
Chitosan is a biopolymer, also known as “hydrocolloids”. Although most hydrocolloids are neutral or negatively charged at acidic pH, chitosan is charged positively due to the presence of highly reactive amino groups. Chitosan is a linear polysaccharide composed of N-acetyl, D-glucosamine, and D-glucosamine units [6]. Chitosan is not extensively available in nature and is thus usually derived from chitin by the partial deacetylation in alkaline solutions at elevated temperatures. Chitosan has attracted attention for food and paint applications owing to its superior characteristic properties, such as degradability, solubility in weak acids, pH-sensitivity, film-forming property, biocompatibility, non-antigenic, absence of toxicity, and low-cost [7,8,9]. Moreover, because of its natural origin and multiple possible applications, like preparation of biodegradable films, blends, coatings, composites, nanocomposites, etc., it has attracted attention of both the scientific community and various industries, particularly the food and paint industries (Figure 1). This review mainly focuses on the physicochemical properties of chitosan, the development of composite materials, and its various applications in water treatment, paints, and food industries.

2. Chitosan and its Properties

2.1. Source and Extraction

Chitin is a linear homo-polysaccharide comprising of b-(1, 4)-linked N-acetyl-D-glucosamine units (Figure 2). Chitin is commonly present in invertebrates, such as crustacean shells or insect cuticles, as well as in the cell walls of fungi, some mushroom envelopes, green algae, and yeasts [10,11,12]. Abdulwadud et al. reported that crustacean shells usually contain 20–30% chitin, 30–40% proteins, 30–50% calcium carbonate/phosphate, and some pigments (astaxanthin, canthaxanthin, lutein, or β-carotene), which varies depending on the sources, or species of sources, and harvesting seasons [13]. Chitosan has been extracted from shrimp shells [14,15,16,17], fish scales of Labeo rohita [18], squid gladius (Loligo vulgaris) [19], locust waste [20], honey bees waste [21], fungus like Aspergillus niger [22], silkworm chrysalides [23], fishery waste [18], and blue crab (Callinectes sapidus) waste [24], amongst others.
Generally, chitin is commercially extracted from the exoskeleton of crustaceans (crab and shrimp shells) by acid treatments, followed by treatment with alkali to remove the calcium carbonates and proteins, respectively. The extraction process includes three major steps: demineralization, deproteinization, and depigmentation/discoloration (Figure 3). The demineralization step comprises of the elimination of calcium carbonate and calcium chloride, which are the primary inorganic compounds in a crustacean’s exoskeleton. The digestion reaction is usually carried out in dilute hydrochloric acid (HCl) solution followed by filtration, washing, and drying. The emission of carbon dioxide (CO2) gas is a significant indicator of the removal of mineral contents from the materials. In the second step, deproteinization is performed using an alkaline solution, such as dilute sodium hydroxide (NaOH), followed by filtration, washing, and drying, similar to the first step, as described above. Proteins that are extracted from crustacean waste shells during this process have found use in animal feed [25]. The final step, depigmentation/discoloration, is a purification process during which colour pigments such as astaxanthin and β-carotene are removed using various organic and inorganic solvents, such as sodium hypochlorite, acetone, and hydrogen peroxide, to obtain a purified chitin [26]. The most common process for deacetylation of chitin is the treatment with concentrated sodium or potassium hydroxide solutions at elevated temperatures. The acetyl (-C2H3O) group is removed from the polymer chain of chitin resulting in the formation of an amino (-NH2) group, thus leading to the N-acetyl-glucosamine and D-glucosamine copolymer.

2.2. Physico-Chemical Properties of Chitosan

2.2.1. Degree of Deacetylation (DD)

The degree of deacetylation is one of the most significant chemical characteristics of chitosan that determines the content of free amino groups (-NH2) that is formed by the partial replacement of acetyl groups (-C2H3O) resulting in a copolymer of N-acetyl-glucosamine and D-glucosamine. Copolymers formed containing higher than 50% D-glucosamine units are typically considered as chitosan, whereas copolymers with more than 50% N-acetyl-glucosamine units are referred to as chitin. For chitosan, the percentage of D-glucosamine units are termed as the degree of deacetylation (DD), whereas for chitin, the percentage of N-acetyl-glucosamine units are known as the degree of acetylation (DA). The degree of deacetylation (DD) of chitosan (ratio of D-glucosamine to the sum of D-glucosamine and N-acetyl D-glucosamine) provides an indication of the number of amino groups in the polymer chains (e.g., D-glucosamine residues of 70% in deacetylated chitin corresponds to a deacetylation degree of 70% and acetylation degree of 30%).
The deacetylation of chitin begins in the amorphous regions prior to the crystalline regions, which occur by hydrolysis through chemical and biological (enzymatic) processes. Chemical treatment methods generally involve acidic or alkaline treatments under a nitrogen environment, or by the addition of sodium borohydride to NaOH solutions, to avoid any undesirable side reaction. Enzyme hydrolysis is environmentally friendly but is comparatively more expensive and thus primarily limited to laboratory-scale experiments [27]. Researchers determine the DD of chitosan using acid-base titration [28], potentiometric titration [29], conductometric titration [30], 1H-NMR spectroscopy [31,32], elemental analysis [30], Fourier transform infrared (FTIR) spectroscopy [33], UV spectrophotometric analysis [34], capillary zone electrophoresis [35], and Raman spectroscopy [36].
DD indicates the amount of amino groups in chitosan polymer, which will affect the properties of chitosan, such as charge, density, solubility, crystallinity, degradation behaviour, mechanical, barrier, and thermal properties [37,38,39]. An increased percentage of amino groups in chitosan polymer makes it soluble in weak acids, a characteristic difference from chitin. The amino groups in chitosan polymer, which is highly reactive, contribute towards its versatility for utilization in various industrial applications. Recently, Zhuang et al. investigated the effect of deacetylation degree on mechanical and barrier properties of chitosan films with three different DD values, 81.0%, 88.1% and 95.2%, wherein CH films with higher DD values (88.1% and 95.2%) were found to have better water barrier property and tensile strength compared to films obtained with a chitosan value of 81.0% DD [37]. It has been reported that the antimicrobial efficiency also improves with the increase in the degree of deacetylation of chitosan that is generally attributed to the increase in the number of positive charges from the amine groups [39].

2.2.2. Molecular Weight (MW)

The molecular weight (MW) of chitosan also influences the physicochemical and antimicrobial properties. Chitosan are categorised in three different forms: high molecular weight (HM-CH) chitosan, low molecular weight (LM-CH) chitosan, and oligochitosan (O-CH, short-chained chitosan) [40]. Jongsri et al. reported the effect of molecular weights on the coating ability of chitosan and the postharvest quality of mango fruit by using three different molecular weight chitosan, namely, high molecular weight chitosan (HM-CH: 360 kDa), medium molecular weight chitosan (MM-CH: 270 kDa), and low molecular weight chitosan (LM-CH: 40 kDa) [41]. HM-CH coatings were found to be effective in delaying the ripening of mango fruit by retaining the titratable acidity, fruit firmness, and slowing down the rate of weight loss, ethylene production, and respiration. Additionally, HM-CH-coated fruits exhibited no incidences of spoilage throughout the reported storage period of 16 days. More recently, Zhong et al. evaluated the effect of MW on film-forming ability, electrostatic spraying atomization performances, and other film characteristics. Chitosan films were prepared with different molecular weights of chitosan (MW 6.55 kDa, 12.93 kDa and 47.70 kDa) using the electrostatic spraying (ES) technique [42]. The results indicated that with an increase in the MW of chitosan, some film-forming solution properties, such as conductivity, viscosity, surface tension, and contact angle, were raised due to the increase in the proportion of amine-groups and degrees of CH chain entanglements. Moreover, with the increase in MW, the water barrier property and tensile strength of CH films were also found to improve. However, the antibacterial capacities of chitosan films against Escherichia coli and Listeria innocua were inferior for higher MW chitosan-based coatings [42]. High molecular weight chitosan cannot pass through the bacterial membrane and hence, they stack on the cell surface, which may alter the membrane permeability that effects the transport of nutrients into the microbial cell membrane, resulting in cell lysis, whereas chitosan with a lower molecular weight can proactively penetrate into the nuclei of a microorganism and could bind with DNA, inhibiting synthesis of mRNA and resulting in cell death [43,44]. No et al. however, reported that the antimicrobial activity of chitosan was greater with lower molecular weight for Gram-negative bacteria, but not for Gram-positive bacteria, which is still an area of contention amongst researchers [45].

2.2.3. Solubility

Chitosan is a semi-crystalline polymer due to the strong inter- and intra-molecular hydrogen bonds. Solubility plays a critical role in various applications of chitosan as it is readily soluble in dilute acidic solutions at pH 6.0, but insoluble in most organic solvents. The pKa value of primary amine groups of chitosan is ~6.3, and thus, under acidic conditions the amine groups are protonated, leading to the repulsion between positively charged macromolecular chains, which allows water molecules to diffuse in and solubilize the polymer. Chitosan precipitates from solutions at pH 6.0 or above, limiting the use of chitosan in basic conditions. Derivatives of chitosan such as acyl-chitosan [46], N-alkyl-chitosan [47], hydroxyalkyl-chitosan [48], PEG-chitosan [49], carboxymethyl chitosan acyl thiourea [50], and TEMPO-laccase oxidised chitosan [51] have been synthesized to improve the solubility in water over broader pH ranges. Water-soluble derivatives of chitosan have been reported to be effective in food, paints, and water treatment applications [52,53,54].

2.3. Antimicrobial Properties

Allan and Hadwiger first reported the antifungal properties of chitosan and suggested that chitosan does not only possess fungicidal properties, but is also more effective on a wider range of fungi than chitin [55]. Since then, several researchers have evaluated the antimicrobial nature of chitosan against different microorganisms and their action mechanisms, but no clear consensus on the mechanism of antimicrobial activity of chitosan has been reached [56,57,58,59,60]. Several mechanisms have been proposed to explain the antimicrobial properties of chitosan. These include: (i) interactions between the positively charged amine groups of chitosan and the negatively charged microbial cell membranes, leading to leakage of cellular constituents; (ii) activation of several defence mechanisms in the host tissue by chitosan molecules acting as a water-binding agent and hindering several enzymes by blocking their active centres; (iii) chitosan as a chelating agent, selectively binding metals and then preventing the microbial growth; (iv) chitosan (high-molecular-weight) forms an impervious polymeric layer on the cell surface that alters cell permeability and ultimately blocks the entry of nutrients into the cell; (v) penetration of chitosan into microbial cytosol that may bind with DNA, resulting in alterations for the synthesis of mRNA and proteins, mostly prevalent with low-molecular-weight chitosan; (vi) adsorption and flocculation of electro-negative materials in the cell, hampering the physiological properties of microorganisms, triggering cell death.
The most widely accepted mechanisms for antimicrobial activity of chitosan is the interaction between the positively charged amine groups of chitosan and the negatively charged microbial cell membranes. In acidic solutions (pH < 6.3) chitosan has a polycationic nature and the positively charged amino groups of chitosan interact with negatively charged components on microbial cell membranes, causing extensive alterations to the cell surface and membrane barrier properties, leading to leakage of intracellular contents that results in cell death. Tyagi et al. have demonstrated this hypothesis through a mechanistic study of chitosan nanoparticles against Gram-positive bacteria, S. aureus [56]. As chitosan has pKa ~6.3, in mildly acidic conditions it is protonated, leading to a reduction in osmotic stability affecting membrane disruption that may efficiently lead to alterations in cell permeability and leakage of intracellular contents, ultimately imbibing rupture of cell. In addition, positively charged chitosan may interact with the negatively charged teichoic acids in the cell wall of gram-positive microbes leading to the formation of small pores on the cell wall and subsequently leading to leakage of the intracellular components [56]. Li et al. suggested that increased permeability of the outer membrane of Escherichia coli is the primary reason for antibacterial activity of CH against such Gram-negative bacteria. Increased permeability leads to the release of cellular contents followed by cell lysis, as shown through microstructural analysis using transmission electron microscopy (TEM) (Figure 4) [61].

2.4. Self-Healing Properties

The ability of a material to heal or repair damages automatically or with some external stimulation independently is called self-healing. Numerous polymeric materials with self-healing capabilities have been fabricated in recent years [62,63,64,65]. Self-healing materials, being capable of forming reversible bonds or reactions in the networks, enhance the durability of the materials. An example of chitosan-based self-healing materials that have attracted attention are anticorrosion self-healing paints [66,67,68,69]. Despite significant achievements in the development of chitosan-based self-healing materials, several challenges still need to be addressed for wider applications. An appropriate balance between mechanical strength, self-healing capacities, and mechanical robustness is required for the fabrication of newly developed, chitosan-based, self-healing materials.
Applications of self-healing coatings include automotive refinish on the backside of smartphones to stop the development of corrosion in scratches [70], etc. Due to excellent film-forming properties, superior adhesion to metallic surfaces, and self-healing abilities, chitosan-based self-healing coatings have been effective in protecting metal surfaces and metallic pieces [71,72]. Two main approaches have been pursued for corrosion protection in self-healing coatings: (i) the fixing of defects by adding polymerizing agents in polymeric coating matrix and (ii) by using corrosion inhibitors that can protect corroding areas [73]. In anti-corrosion paints, self-healing refers to both dynamic care of the substrate and structural repair of the coatings, offering superior protecting ability and increased longevity of the coating compared to other protective coatings [71]. Chitosan- and cerium (Ce)-based self-healing coatings have been reported to protect aluminium alloy 2024 from corrosion [68,74]. 2-Mercaptobenzothiazole (MBT) has been used as an effective corrosion inhibitor in chitosan-based coating for aluminium alloys 2024. The study revealed that MBT has strong inhibiting ability and even after one week in a full immersion condition no corrosion attack was reported [71]. In the study, the surface properties of the chitosan coatings were also improved by chemical grafting using poly (ethylene-alt-maleic anhydride) (PEMA) and poly (maleic anhydride-alt-1-octadecene) (PMAO) to increase its hydrophobicity, which is important for corrosion protection in atmospheric conditions. Due to good wettability and adhesion properties it was argued that chitosan provides corrosion protection, simultaneously working as a reservoir for the corrosion inhibitor which prevents the formation of pittings on aluminium alloy. The grafting of chitosan at the coating/solution interface with PEMA and PMAO provided an adequate hydrophobic effect, especially in the case of chitosan loaded with MBT, leading to the delay of ingress of electrolyte towards the metal interface. The combination of active corrosion protection due to MBT and the surface hydrophobicity conferred by grafting could be the reason behind the efficient protection from corrosion to aluminium alloy 2024 [71].

3. Chitosan-Based Nanocomposites

Previously, many studies have reported chemical modification of chitosan either by coupling with small molecules or grafting with polymers, for changing/improvement or better use of the intrinsic properties of chitosan. Chitosan has been grafted with different polymers, such as poly-lactide to form polymeric amphiphilic micelles [75] or polyethyleneimine (PEI) to form a branched PEI-g-chitosan with lowered cytotoxicity but higher gene transfection efficiency compared to PEI [76]. More recently, chitosan-based nanocomposites have emerged, where both polymer and nanoparticles contribute to the improvement or enhancement of specific properties. The dispersed nanomaterials contained in chitosan polymer matrix not only improve the physical, mechanical, and thermal stability of chitosan, but also endows the composite with its intrinsic properties, such as high surface area or extraordinary physicochemical properties. Chitosan nanocomposites formed between chitosan and metal/metal oxide, carbon, polymer, or clay materials via physical or chemical interaction and their applications in food, paints, and environmental fields are summarized in Table 1 and Table 2.

3.1. Chitosan-Metal/Metal Oxide

Noble metal, such as silver, are very effective antimicrobial agents [77,78,79] and can be synthesized in situ in a chitosan matrix due to the metal ion chelation capability of chitosan. Taking into account that silver nanoparticles are well-known for their antimicrobial property, chitosan-silver nanocomposite coatings materials have been studied on metal, glass, wood, etc., surfaces [80,81,82]. Metal oxide nanomaterials are commonly applied in polymer matrix as filler materials to enhance the antimicrobial and mechanical properties of the films and coatings, which are mainly used for food packaging and food preservation applications [83,84,85,86]. Silica nanoparticles in chitosan were reported to selectively absorb rare earth elements [87], while zinc oxide nanoparticles were reported to photo-catalytically generate reactive oxygen species (ROS), leading to high anti-diatom and anti-bacterial activities under sunlight [85,86].

3.2. Chitosan-Carbon Materials

Carbon-based nanomaterials, such as CNT, graphene, and graphene oxide have been well-studied. Incorporation of graphene oxide into chitosan improves the mechanical properties of chitosan in addition to enhancing its antimicrobial and pollutant removal abilities [88,89]. Chitosan being a biocompatible polymer has been applied to improve the solubility of CNT and reduce its toxicity to facilitate practical applications (Table 1) [90].

3.3. Chitosan-Polymer Mixture or Copolymer

Chitosan is often introduced to other types of polymers to form mixture or copolymers in order to enhance the properties for specific applications (Table 1). Attributed to the chemical reactivity of primary amine groups in chitosan, polymers containing activated carboxyl groups can be covalently linked with chitosan, commonly employing carbodiimide crosslinking reagents to form an amide bond between amine and carboxyl groups [91,92]. For polymers containing abundant hydroxyl groups, such as cellulose, physical mixture/interaction with chitosan is often used for the preparation of chitosan-polymer hydrogels [93], simple Van der Waal interactions occur that do not change chemical structures. Alternatively, chemical linking of polymers containing hydroxyl groups to chitosan works by the activation of hydroxyl into imidazolyl carbamate intermediates, that react with primary amine groups in chitosan to form N-alkyl carbamate linkages [94]. Since chitosan is a polycationic molecule, it can easily interact with negatively charged electrolyte/polymers/particles through electrostatic interactions. For instance, a chitosan–nucleic acid nanoparticle complex can be formed by coacervation between the positively charged amine groups and negatively charged phosphate groups in the nucleotide. Similarly, alginic acid/alginate as a natural polysaccharide has a similar chemical structure to chitosan but contains carboxylic instead of amine groups. Due to the opposite charges, chitosan and alginate can easily form electrostatic complexes [95].

3.4. Chitosan-Clay Composites

Clay is finely grained soil that is mainly composed of metal oxides or hydroxides with traces of organic matters. Owing to its small particle size (ca. 1 μm) and excellent colloidal properties, clay has been widely used in different applications, such as for water purification, as an odour absorbent, and as a lubricant in construction industries. Because of the structural characteristics, clay nanotubes and platelets can be used to load active agent to improve the passive barrier performances of anticorrosive coating [96]. Due to the electrostatic interaction between chitosan and clay, the composites are normally combined through adsorption, gelation, or intercalation. In chitosan-clay nanocomposites, clay exhibits its characteristic properties, such as absorption of specific species [97,98] or hemostatic properties [99], while chitosan can provide a higher loading or the cross-linked chitosan network as a support or scaffold for clay (Table 1).
Table 1. Examples of chitosan-based nanocomposites and their applications.
Table 1. Examples of chitosan-based nanocomposites and their applications.
Chitosan Molecular Weight/ViscosityType of Nanomaterials in CompositeName of Nanomaterial/Polymer/ClayPreparation Method of Chitosan NanocompositeForm of Chitosan NanocompositesSpecific ApplicationKey/Enhanced PropertiesApplication FieldReference
100 kDaMetalAg nanoparticlesIn situ reduction on chitosanThin film coating on bandageAntibacterial activity against E. coli and S. aureusInactivation bacterial metabolismAntimicrobial[100]
Medium molecular weightMetalAg nanoparticlesIn situ reduction on chitosanAg nanoparticles anchored on chitosan particlesSensing of ammonia in solutionSensitive in optical absorption intensity and wavelengthEnvironment[101]
Medium molecular weightMetal oxideZnO nanoparticlesBlendingThin film coatingAntifouling preventionAnti-diatom activity and antibacterial activity against the marine bacteriumAnti-biofouling[85,86]
Low viscosityMetal oxideSiO2 nanoparticlesIn situ Stöber method grown on chitosanSlurry packed in liquid chromatography (LC) columnAdsorption of rare-earth elementsHigh adsorption efficiency, selectivity, and reusabilityEnvironmental[87]
190–310 kDaCarbonGraphene oxideCross-linkingThin filmAntimicrobial against E. coli and B. subtilisImproved mechanical and antimicrobial propertiesAntimicrobial[88]
300 kDaCarbonGraphene oxideCross-linkingHydrogelRemoval of dyes and metal ions from waterTunable surface charge; efficient removal of pollutantsEnvironmental[89]
N/APolymerlow density poly-ethylene (LDPE) filmGraftingCoatingSignificant changes in surface wettabilityImproved anti-thrombogenic propertiesAntifouling[92]
N/AClayHalloysite clay nanotubesElectrostatical adsorptionCoatingAnticorrosive protectiveImproved passive barrier protective and self-healingEnvironmental[96]
50–190 kDaClayBentonite and sepioliteBlendThin filmWinemaking applicationEnhanced immobilization of protease but negatively affected catalytic propertiesAntimicrobial[97]
Medium molecular weightClayBentoniteGelation and lyophilizationBeadCarbon dioxide adsorptionHigh adsorption capacity under moderate conditionEnvironmental[98]

4. Applications of Chitosan-Based Nanocomposites

4.1. Water Purification

The use of synthetic dyes is increasing day-by-day for industrial applications, particularly in the textile industry, which leads to severe water pollution because of their discharge into water bodies without suitable treatments. Over 10,000 different colorants (dyes and pigments) are used in textile industries and over 7 × 105 tons of synthetic dyes are annually produced worldwide [102,103]. Most of the synthetic dyestuffs are discharged into the ecosystem without appropriate treatments, which has triggered global environmental problems [103]. Removal of dyes from water bodies is challenging because of their inert nature and existence in low concentrations. Chitosan has received attention in water purification as it is an inexpensive biopolymer and also due to the presence of a large number of reactive amino (-NH2) and hydroxyl (-OH) groups. Adsorption of acid dyes with chitosan and modified chitosan occurs because of the electrostatic interaction between negatively charged dye ions and the protonated amino groups [104]. Shen et al. demonstrated that the removal of dyes from alkaline effluent involves chelating interactions rather than electrostatic interactions [105].
The removal of dye from wastewater using nanocomposites of chitosan has been achieved using several processes, such as physical adsorption, ion-exchange, hydrogen bonds, hydrophobic attractions, and chemical bonding. Chitosan-based composite fibres (MNPs/ZnPc-CS) and pellets of zinc photocatalysts (ZnPc)-supported metallic and bimetallic nanoparticles have been synthesized by Ali et al. for metal ions uptake [106]. The MNPs/ZnPc-CS fibres were used as dip-catalysts for the reduction of nitrophenols and azo dyes like methyl orange (MO) and cango red (CR). The results showed that the developed composites exhibited excellent catalytic efficiency and recyclability in the reduction of these dyes. Recent studies conducted by many researchers on the removal of dyes from wastewater using chitosan-based nanocomposites are summarized in Table 2.
Table 2. Chitosan-based nanocomposites for removal of dyes from wastewater.
Table 2. Chitosan-based nanocomposites for removal of dyes from wastewater.
Chitosan-Based NanocompositeDye/MetalpHRemoval ProcessReferences
CS/AgNPsMethyl orange3–11Photocatalytic decolourization[107]
CS/AuNPs4-nitrophenolNo dataCatalytic reduction[108]
CS/TiO2Rhodamine-B, Congo red3–11Photocatalytic degradation under visible light irradiation[109]
CS/Polyaniline/CdSReactive Blue-196Adsorption[110]
CS/PVA/ZnOAcid Black-1No dataAdsorption[111]
CS/SiO2/CNTDirect Blue-71, Reactive Blue-190–12Adsorption[112]
CS/lignin/titaniaBrilliant BlackNo dataAdsorption[113]
CS/Bio-silicaAcid Red 881–12Adsorption[114]
CS/Palladium4-NitrophenolNo dataCatalytic hydrogenation[115]
CS/SnO2Methyl orange, Rhodamine-BNo dataPhotocatalytic degradation[116]
CS/Ag3PO4/CdSMethyl orange3–8Photocatalytic decolourization[117]
CS/zirconium tungstateReactive Blue-21, Reactive Red-141, Rhodamine-6G and binary mixture; RB+RR, RR+RH, RB + RHNo dataPhotocatalytic degradation[118]
CS/SnO2 intercalated polyaniline (PANI)Methylene blue Reactive yellow-15No dataPhotocatalytic degradation under direct sunlight irradiation[119]
CS/TiO2 fibers supported zero-valent metal nanoparticles (like Cu0, Co0, Ag0 and Ni0)Methyl orange, Congo red (CR), Methylene blue, Acridine orange, 4-nitrohphenol, 2-nitrophenol, 3-nitrophenol, 2,6-dinitrophenolNo dataCatalytic reduction[120]
CS coated cotton cloth supported zero-valent metal nanoparticlesMethyl orange, Methylene blue,4-nitrohphenol, Rhodamine-BNo dataCatalytic reduction[121]
CS/MoO3/TiO2Methyl orangeNo dataPhotocatalytic degradation under solar light[122]
Zhou et al. fabricated three low-cost polypyrrole-based composites, i.e., polypyrrole-chitosan-lignosulfonate (PPY-CS-LS), polypyrrole-chitosan (PPY-CS), and polypyrrole-lignosulfonate (PPY-LS) via polymerization (in-situ) of pyrrole monomers with chitosan (CS) and/or lignosulfonate (LS) as dispersants in order to improve the dye adsorption capacity of polypyrrole [123]. The selective adsorption properties of these composites were investigated for six dyes, i.e., methylene blue (MB), malachite green (MG), amaranth (AM), acid orange 10 (AO10), congo red (CR), and acid blue74 (AB74). The synergistic effects of amino/hydroxyl-containing functional groups from CS, sulfonic groups from LS, and nitrogen-containing functional groups from PPY chains resulted in high adsorption performance (feasible and spontaneous) for dyes with the PPY-CS-LS composite.

4.2. Antifouling Paints and Coatings

Marine biofouling is the undesirable growth of organisms on submerged surfaces [124]. Any submerged, clean, and unprotected substrata will be quickly colonized by microorganisms (bacteria, diatoms, and unicellular eukaryotes) and later by larvae of invertebrates and spores of algae [125,126]. Biofouling has huge economic impacts in maritime industries [127]. Biofouling significantly increases vessel drag, fuel consumption, clogs membranes and pipes, and also interfere with the stability of sensors attached to the vessels. Worldwide, countries spend billions of US dollars in order to manage and prevent this problem [128]. Currently, antifouling paints utilize toxic biocides that pollute the environment [127]. Thus, new low-cost and non-toxic antifouling paints are urgently needed. Chitosan has been proposed as a promising antifouling agent due to its antimicrobial properties [129] (Table 3). Plastic substrates coated with 2.5% chitosan significantly reduced the settlement of bryozoan Bugula neritina compared to untreated substrates. Chitosan mixed with a non-toxic paint base and applied to plastic substrates were found to protect the substrates from bacterial fouling over one week of laboratory experiments [130]. Chitosan incorporated into a silicon-polyurethane marine paint was exposed to biofouling for over two months in cold seawater [129]. Experiments demonstrated a short-term antibacterial action of chitosan, while no anti-algal action was observed. In contrast, chitosan paints significantly reduced densities of micro-fouling on the surface of a sea glider exposed to periodical oscillations of environmental conditions in the Sea of Oman. Moreover, it was found that the structure of microbial communities formed on chitosan paints were similar to unprotected surfaces and were totally different from what is found on surfaces coated with copper-based antifouling paints, suggesting that chitosan-based coatings have minimal negative impact on marine communities [131].
Few researchers have combined chitosan with nanoparticles in order to increase antifouling properties and stability of coatings (Table 3). Chitosan-ZnO hybrid coatings were found to inhibit bacterial and diatom fouling more efficiently than chitosan coatings alone [86]. In another study, nanocomposite films of chitosan mixed with silver nanoparticles were found to be effective against E. coli and Bacillus bacteria and thus it was proposed that these “green” films can be used as packaging materials [132]. Nitric oxide (NO)-releasing chitosan coatings were found to exhibit dose-dependent behaviour for the degradation of biofilms of Pseudomonas aeruginosa [133]. The effect of NO-chitosan coating was better than chitosan alone, suggesting synergistic action of chitosan and NO. Chitosan functionalized with polyelectrolyte brushes were tested against bacteria in laboratory experiments and against biofouling in static field experiments in the Mediterranean sea, showing promising antifouling activities [134].
Chitosan has been applied to create membranes with antifouling properties (Table 3). Chitosan membranes had strong antibacterial properties [135] and growth of gram-positive bacteria was reduced more significantly than gram-negative bacteria. Cellulose membranes with smaller pore sizes were modified with higher molecular weight chitosan in order to improve their activity against gram-positive Staphylococcus aureus and gram-negative E. coli bacteria [136]. A forward osmosis (FO) membrane was fabricated using layer-by-layer assembly of chitosan and graphene oxide nanosheets on a porous support layer, which was found to be effective in fouling rejection of alginate in laboratory experiments [137]. Similarly, ultrathin antibacterial protective nanocoatings were prepared from ionic derivatives of chitosan using a layer-by-layer deposition methodology [138]. Silicone and glass surfaces coated with this nanocoating were able to prevent the adsorption of proteins and biofilm formation by S. aureus. The antifouling effect of chitosan nanocoating was found to depend on its thickness. Chitosan-modified polyacrylonitrile (PAN) hollow fibre membranes were reported to have better antibacterial properties against E. coli and Bacillus subtilis compared to unmodified PAN membranes [139]. Composite polyethersulfone (PES) nanofiltration membranes synthesized by blending O-carboxymethyl chitosan (O-CMC) and iron oxide (Fe3O4) nanoparticles were found to have considerably higher water flux, permeation, and fouling resistance compared to the unfilled PES membrane [140]. In a similar study, PES membranes prepared using O-CMC and silver nanoparticles were found to prevent protein fouling as well as having a good antibacterial property towards E. coli and S. aureus [141].
Table 3. Chitosan-based antifouling applications.
Table 3. Chitosan-based antifouling applications.
ApplicationCarrier/AdditiveType of the StudyEffective AgainstReferences
FilmsNoLaboratoryBryozoan[130]
FilmsNoFieldMicro-fouling[131]
Ultra-thin nanocoatingsNoLaboratoryBacteria[138]
FilmsPolyelectrolyte brushesLaboratory and fieldPathogens, micro-fouling and macro-fouling[134]
PaintsSilicon-polyurethaneFieldMicro-fouling and macro-fouling[129]
ZnO nanocompositesZnO nanoparticlesLaboratoryMicro-fouling[86]
ZnO nanocompositesZnO nanoparticlesLaboratoryPathogenic bacteria and fungi[85]
Silver nanocomposite filmsSilver nanoparticlesLaboratoryPathogenic bacteria[132]
Cellulose membranesNoLaboratoryPathogenic bacteria[136]
PAN-chitosan membranesNoLaboratoryBacteria[139]
Chitosan membranesNoLaboratoryPathogenic bacteria[135]
Forward osmosis membranesGraphene oxide nanosheetsLaboratoryProteins[137]
PES membranesFe3O4 nanoparticlesLaboratoryProteins[140]
PES membranesSilver nanoparticlesLaboratoryProteins, bacteria[141]

4.3. Shelf-Life Extension of Fruits and Vegetables

During postharvest transportation and storage, fresh produce (fruits and vegetables) undergo quality deteriorations due to the various physiology reactions and processes, such as postharvest respiration, ripening, ethylene production, and senescence. These physiological changes are directly influenced by the surrounding environment, i.e., temperature, oxygen, humidity, and light, that lead to loss of water, texture, colour, and nutrients of the produce [142,143]. Microbiological spoilage leads to postharvest losses of about 15% to 50% of fruits and vegetables produced worldwide [144]. In developing countries, the percentages of product losses are quite high due to a lack of appropriate technologies for postharvest storage of fruits and vegetables. The physiological, biochemical, and environmental changes promote the growth of postharvest pathogens that are the major causes of loss/damages in the supply chain. However, controlling postharvest destruction of fresh produce involves the application of synthetic antimicrobials, fungicides, and insecticides. Consumer concerns about the adverse effect of synthetic chemical residues on human health and environment, and the chances of the development of pathogen resistance, have led global scientific research towards the development of alternative strategies for the preservation of fresh produce [145].
The application of a natural polymer (biopolymer)-based films and coatings on food surfaces have recently gained interest for the shelf-life extension of fresh produce due to their similar functions to those of conventional protection or synthetic packaging. Out of several natural polymers, the use of chitosan-based treatment at the postharvest stages has been considered to be a suitable alternative treatment to replace the use of synthetic chemicals [146]. Chitosan-based films and coatings have been reported to effectively extend quality and storability of food products in general, and of fresh agricultural produce in particular, due to its excellent natural antioxidant, antibacterial, and antifungal activities [147,148,149,150].

4.3.1. Packaging Films

One of the main research areas in food industries has focused on developing new packaging techniques capable of improving the post-harvest life of fresh foods based on their interaction with packaging. Such techniques are well-known as “active packaging”. Active packaging can be defined as the incorporation of an active system/materials into packaging film or a container to maintain the quality or extend the shelf-life of food products. In particular, antimicrobial packaging is one of the most innovative and promising active packaging systems developed over the last decade, and these systems are capable of inhibiting microbial growth and action, leading to the maintenance of food quality with improved shelf-life [148,151,152].
Biopolymer-based packaging films have received considerable interest as an alternative packaging material to plastics. The bioplastics are usually degradable under appropriate conditions of moisture, temperature, and oxygen availability and do not produce any toxic residues. The problems associated with biodegradable polymers are three-fold (3P): performance, processing, and price. Problems due to “performance and processing” are universal to almost all biodegradable polymers irrespective of their origin [153]. In particular, brittleness, low heat-distortion temperature, high gas and vapour barrier properties, and poor resistance to harsh processing operations have strongly limited extensive applications of biopolymers. The application of nanotechnology has opened new options for improving properties of biopolymers. The incorporation of nanoscale materials as a filler into the biopolymer matrix have shown to markedly improve mechanical, thermal, barrier, and other physio-chemical properties, compared to the base polymers and conventional (microscale) composites [154]. Nano-sized fillers can be either inorganic or organic materials, such as clay (e.g., montmorillonite), natural antimicrobial agents (e.g., nisin), metal (e.g., silver, gold), and metal oxides (e.g., zinc oxide (ZnO), titanium dioxide (TiO2)), to be the material of choice due to its antimicrobial activity, thermal stability and ability to improve mechanical properties of biopolymer films [147,149,153,155,156,157]. Chitosan-ZnO hybrid coatings on polyethylene films have been reported to reduce growth of pathogenic bacteria and fungi [85], as well as increase the shelf life of okra (Abelmoschus esculentus) vegetables [158]. Zhang et al. developed a chitosan-TiO2 composite film for the packaging of red grapes and evaluated antimicrobial activity against food-borne pathogenic microbes, namely E. coli, S. aureus, Candida albicans, and Aspergillus niger [147]. Results showed that the chitosan-TiO2 composite films were effective against all four tested microbes, with 100% sterilization within 12 h. The composite film could successfully protect red grapes from microbial infection thus enhancing their shelf-life (Figure 5). Recently, several other researchers have studied the fabrication, characterization, and application of chitosan-based nanocomposites films with antimicrobial properties for food packaging applications. A summary of recent work done on antimicrobial nanocomposite films and their applications in extending the shelf-life of fruits and vegetables are given in Table 4.

4.3.2. Coatings of Fruits and Vegetables

Coatings provide a thin layer of materials on food surfaces to maintain or control the ingress of gases, moisture, and solutes from the environment. Additionally, coatings can also act as a carrier for functional antimicrobial and antioxidant substances to additionally enhance its functionality for ensuring food quality and food safety of fresh produce (Figure 6). Coatings on the surface of fruits and vegetables could provide the following functions:
  • Offer barrier properties against moisture and oxygen
  • Help to deliver antimicrobial activity to inhibit or delay the microbial growth
  • Deliver antioxidant effects that help to reduce the oxidation process, loss of colour, vitamins, etc.
  • Help to maintain the loss of volatile components and stop acquiring foreign odours
Several researchers have reported the development or fabrication of chitosan-based nanocomposite coating formulations to improve post-harvest storage life by studying moisture loss, reduced respiration process, deliverability of antimicrobial and antioxidant agent, etc. A brief summary of the major coating formulations and their applications on fresh and minimally processed fruits and vegetables are given below in Table 5.

5. Conclusions and Future Perspectives

The present review reported on the current and most important topics regarding the development of chitosan-based nanocomposite coating formulation for food preservation, water treatment, and anti-corrosive and self-healing paint applications. Over the past several decades, chitosan has emerged as a promising biomaterial for various industrial applications including food, pharma, paint, cosmetic, and textile industries, due to their natural origin, structural similarity to glycosaminoglycan’s (naturally presented in native tissues), biocompatibility, biodegradability, low toxicity, antimicrobial, and antifouling activities. Biopolymer-based edible films and coatings play a significant role in prolonging the post-harvest life and improving the quality of fresh fruits and vegetables. It protects the fresh fruits and vegetables from damages or deteriorations during storage after harvesting by reducing the rate of moisture and gas transfer, by delaying respiration, senescence, etc., and by maintaining structural integrity or firmness and sensory attributes. Technology advancement enabling the preparation of multifunctional chitosan-based coatings or films could be promising to be used as packaging materials for food applications. Chitosan-based coatings containing active anticorrosive agent with self-healing ability have great potential for application in paint industries due to its good film-forming properties, superior adhesion abilities to substrates, antifouling properties, and the ability to reversibly form complexes with potential corrosion inhibitors. Chitosan and its nanocomposites have been used for removing dyes from textile wastewater. It has also found application in the prevention of biofouling from submerged surfaces to membranes. More practical applications of chitosan nanocomposites with metal oxides and clay will emerge in the near future as the world is grappling to reduce synthetic polymer waste in our ecosystems.

Author Contributions

Conceptualization, J.D. and S.D.; writing—original draft preparation, S.K., F.Y., S.D.; writing—review and editing, S.K., F.Y., S.D., J.D.

Funding

S.K. is thankful to Department of Biotechnology, Government of India for providing financial support (sanction letter vide no. BT/20/NE/2011) to pursue post-doctoral research at Functional Materials, KTH Royal Institute of Technology, Stockholm, Sweden through “Biotechnology Overseas Associateship Award for NER Scientists”. S.D. acknowledge financial support by TRC grant RC/AGR/FISH/16/01.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Tsigos, I.; Martinou, A.; Kafetzopoulos, D.; Bouriotis, V. Chitin deacetylases: New, versatile tools in biotechnology. Trends Biotechnol. 2000, 18, 305–312. [Google Scholar] [CrossRef]
  2. Crini, G. Non-conventional low-cost adsorbents for dye removal: A review. Bioresour. Technol. 2006, 97, 1061–1085. [Google Scholar] [CrossRef] [PubMed]
  3. Rinaudo, M. Chitin and chitosan: Properties and applications. Prog. Polym. Sci. 2006, 31, 603–632. [Google Scholar] [CrossRef]
  4. Dhillon, G.S.; Kaur, S.; Brar, S.K.; Verma, M. Green synthesis approach: Extraction of chitosan from fungus mycelia. Crit. Rev. Biotechnol. 2012, 33, 379–403. [Google Scholar] [CrossRef] [PubMed]
  5. Benhabiles, M.S.; Salah, R.; Lounici, H.; Drouiche, N.; Goosen, M.F.A.; Mameri, N. Antibacterial activity of chitin, chitosan and its oligomers prepared from shrimp shell waste. Food Hydrocoll. 2012, 29, 48–56. [Google Scholar] [CrossRef]
  6. Kumirska, J.; Czerwicka, M.; Kaczyński, Z.; Bychowska, A.; Brzozowski, K.; Thöming, J.; Stepnowski, P. Application of Spectroscopic Methods for Structural Analysis of Chitin and Chitosan. Mar. Drugs 2010, 8, 1567–1636. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  7. Bonilla, J.; Fortunati, E.; Atarés, L.; Chiralt, A.; Kenny, J.M. Physical, structural and antimicrobial properties of poly vinyl alcohol–chitosan biodegradable films. Food Hydrocoll. 2014, 35, 463–470. [Google Scholar] [CrossRef]
  8. Croisier, F.; Jérôme, C. Chitosan-based biomaterials for tissue engineering. Eur. Polym. J. 2013, 49, 780–792. [Google Scholar] [CrossRef] [Green Version]
  9. Kumari, S.; Rath, P.K. Extraction and Characterization of Chitin and Chitosan from (Labeo rohit) Fish Scales. Procedia Mater. Sci. 2014, 6, 482–489. [Google Scholar] [CrossRef] [Green Version]
  10. Doiphode, N.; Joshi, C.; Ghormade, V.; Deshpande, M.V. Biotechnological Applications of Dimorphic Yeasts. In Yeast Biotechnology: Diversity and Applications; Springer: Dordrecht, The Netherlands, 2009; pp. 635–650. [Google Scholar]
  11. Amorim, R.V.S.; Ledingham, W.M.; Kennedy, J.F.; Campos-Takaki, G.M. Chitosan from Syncephalastrum racemosum Using Sugar Cane Substrates as Inexpensive Carbon Sources. Food Biotechnol. 2006, 20, 43–53. [Google Scholar] [CrossRef]
  12. Tharanathan, R.N.; Kittur, F.S. Chitin—The Undisputed Biomolecule of Great Potential. Crit. Rev. Food Sci. Nutr. 2003, 43, 61–87. [Google Scholar] [CrossRef] [PubMed]
  13. Nouri, M.; Khodaiyan, F.; Razavi, S.H.; Mousavi, M. Improvement of chitosan production from Persian Gulf shrimp waste by response surface methodology. Food Hydrocoll. 2016, 59, 50–58. [Google Scholar] [CrossRef]
  14. Teli, M.D.; Sheikh, J. Extraction of chitosan from shrimp shells waste and application in antibacterial finishing of bamboo rayon. Int. J. Biol. Macromol. 2012, 50, 1195–1200. [Google Scholar] [CrossRef] [PubMed]
  15. Sedaghat, F.; Yousefzadi, M.; Toiserkani, H.; Najafipour, S. Bioconversion of shrimp waste Penaeus merguiensis using lactic acid fermentation: An alternative procedure for chemical extraction of chitin and chitosan. Int. J. Biol. Macromol. 2017, 104, 883–888. [Google Scholar] [CrossRef] [PubMed]
  16. Younes, I.; Ghorbel-Bellaaj, O.; Nasri, R.; Chaabouni, M.; Rinaudo, M.; Nasri, M. Chitin and chitosan preparation from shrimp shells using optimized enzymatic deproteinization. Process Biochem. 2012, 47, 2032–2039. [Google Scholar] [CrossRef]
  17. Mohammed, M.H.; Williams, P.A.; Tverezovskaya, O. Extraction of chitin from prawn shells and conversion to low molecular mass chitosan. Food Hydrocoll. 2013, 31, 166–171. [Google Scholar] [CrossRef] [Green Version]
  18. Kumari, S.; Kumar Annamareddy, S.H.; Abanti, S.; Kumar Rath, P. Physicochemical properties and characterization of chitosan synthesized from fish scales, crab and shrimp shells. Int. J. Biol. Macromol. 2017, 104, 1697–1705. [Google Scholar] [CrossRef]
  19. Abdelmalek, B.E.; Sila, A.; Haddar, A.; Bougatef, A.; Ayadi, M.A. β-Chitin and chitosan from squid gladius: Biological activities of chitosan and its application as clarifying agent for apple juice. Int. J. Biol. Macromol. 2017, 104, 953–962. [Google Scholar] [CrossRef]
  20. Marei, N.H.; El-Samie, E.A.; Salah, T.; Saad, G.R.; Elwahy, A.H.M. Isolation and characterization of chitosan from different local insects in Egypt. Int. J. Biol. Macromol. 2016, 82, 871–877. [Google Scholar] [CrossRef]
  21. Nemtsev, S.V.; Zueva, O.Y.; Khismatullin, M.R.; Albulov, A.I.; Varlamov, V.P. Isolation of Chitin and Chitosan from Honeybees. Appl. Biochem. Microbiol. 2004, 40, 39–43. [Google Scholar] [CrossRef]
  22. Abdel-Gawad, K.M.; Hifney, A.F.; Fawzy, M.A.; Gomaa, M. Technology optimization of chitosan production from Aspergillus niger biomass and its functional activities. Food Hydrocoll. 2017, 63, 593–601. [Google Scholar] [CrossRef]
  23. Paulino, A.T.; Simionato, J.I.; Garcia, J.C.; Nozaki, J. Characterization of chitosan and chitin produced from silkworm crysalides. Carbohydr. Polym. 2006, 64, 98–103. [Google Scholar] [CrossRef]
  24. Baron, R.D.; Pérez, L.L.; Salcedo, J.M.; Córdoba, L.P.; Sobral, P.J.d.A. Production and characterization of films based on blends of chitosan from blue crab (Callinectes sapidus) waste and pectin from Orange (Citrus sinensis Osbeck) peel. Int. J. Biol. Macromol. 2017, 98, 676–683. [Google Scholar] [CrossRef] [PubMed]
  25. Nguyen, T.T.; Barber, A.R.; Corbin, K.; Zhang, W. Lobster processing by-products as valuable bioresource of marine functional ingredients, nutraceuticals, and pharmaceuticals. Bioresour. Bioprocess. 2017, 4, 27. [Google Scholar] [CrossRef] [PubMed]
  26. Srinivasan, H.; Kanayairam, V.; Ravichandran, R. Chitin and chitosan preparation from shrimp shells Penaeus monodon and its human ovarian cancer cell line, PA-1. Int. J. Biol. Macromol. 2018, 107, 662–667. [Google Scholar] [CrossRef] [PubMed]
  27. El Knidri, H.; Belaabed, R.; Addaou, A.; Laajeb, A.; Lahsini, A. Extraction, chemical modification and characterization of chitin and chitosan. Int. J. Biol. Macromol. 2018, 120, 1181–1189. [Google Scholar] [CrossRef] [PubMed]
  28. Yuan, Y.; Chesnutt, B.M.; Haggard, W.O.; Bumgardner, J.D. Deacetylation of Chitosan: Material Characterization and in vitro Evaluation via Albumin Adsorption and Pre-Osteoblastic Cell Cultures. Materials 2011, 4, 1399–1416. [Google Scholar] [CrossRef] [Green Version]
  29. Jiang, X.; Chen, L.; Zhong, W. A new linear potentiometric titration method for the determination of deacetylation degree of chitosan. Carbohydr. Polym. 2003, 54, 457–463. [Google Scholar] [CrossRef]
  30. Dos Santos, Z.M.; Caroni, A.L.P.F.; Pereira, M.R.; da Silva, D.R.; Fonseca, J.L.C. Determination of deacetylation degree of chitosan: A comparison between conductometric titration and CHN elemental analysis. Carbohydr. Res. 2009, 344, 2591–2595. [Google Scholar] [CrossRef]
  31. Kasaai, M.R. Determination of the degree of N-acetylation for chitin and chitosan by various NMR spectroscopy techniques: A review. Carbohydr. Polym. 2010, 79, 801–810. [Google Scholar] [CrossRef]
  32. Desbrières, J.; Martinez, C.; Rinaudo, M. Hydrophobic derivatives of chitosan: Characterization and rheological behaviour. Int. J. Biol. Macromol. 1996, 19, 21–28. [Google Scholar] [CrossRef]
  33. Kasaai, M. A review of several reported procedures to determine the degree of N-acetylation for chitin and chitosan using infrared spectroscopy. Carbohydr. Polym. 2008, 71, 497–508. [Google Scholar] [CrossRef]
  34. Wu, T.; Zivanovic, S. Determination of the degree of acetylation (DA) of chitin and chitosan by an improved first derivative UV method. Carbohydr. Polym. 2008, 73, 248–253. [Google Scholar] [CrossRef]
  35. Wu, C.; Kao, C.Y.; Tseng, S.-Y.; Chen, K.C.; Chen, S.-F. Determination of the degree of deacetylation of chitosan by capillary zone electrophoresis. Carbohydr. Polym. 2014, 111, 236–244. [Google Scholar] [CrossRef] [PubMed]
  36. Zając, A.; Hanuza, J.; Wandas, M.; Dymińska, L. Determination of N-acetylation degree in chitosan using Raman spectroscopy. Spectrochim. Acta Part A Mol. Biomol. Spectrosc. 2015, 134, 114–120. [Google Scholar] [CrossRef]
  37. Li, X.; Xia, W. Effects of concentration, degree of deacetylation and molecular weight on emulsifying properties of chitosan. Int. J. Biol. Macromol. 2011, 48, 768–772. [Google Scholar] [CrossRef]
  38. Zhuang, C.; Zhong, Y.; Zhao, Y. Effect of deacetylation degree on properties of Chitosan films using electrostatic spraying technique. Food Control 2019, 97, 25–31. [Google Scholar] [CrossRef]
  39. Paul, T.; Halder, S.K.; Das, A.; Ghosh, K.; Mandal, A.; Payra, P.; Barman, P.; Das Mohapatra, P.K.; Pati, B.R.; Mondal, K.C. Production of chitin and bioactive materials from Black tiger shrimp (Penaeus monodon) shell waste by the treatment of bacterial protease cocktail. 3 Biotech 2015, 5, 483–493. [Google Scholar] [CrossRef]
  40. Peniche, C.; Peniche, H.; Pérez, J. Chitosan based self-assembled nanoparticles in drug delivery. Polymers 2018, 10, 235. [Google Scholar]
  41. Jongsri, P.; Wangsomboondee, T.; Rojsitthisak, P.; Seraypheap, K. Effect of molecular weights of chitosan coating on postharvest quality and physicochemical characteristics of mango fruit. LWT 2016, 73, 28–36. [Google Scholar] [CrossRef]
  42. Zhong, Y.; Zhuang, C.; Gu, W.; Zhao, Y. Effect of molecular weight on the properties of chitosan films prepared using electrostatic spraying technique. Carbohydr. Polym. 2019, 212, 197–205. [Google Scholar] [CrossRef] [PubMed]
  43. Kim, K.W.; Min, B.J.; Kim, Y.-T.; Kimmel, R.M.; Cooksey, K.; Park, S.I. Antimicrobial activity against foodborne pathogens of chitosan biopolymer films of different molecular weights. LWT -Food Sci. Technol. 2011, 44, 565–569. [Google Scholar] [CrossRef]
  44. Zheng, L.-Y.; Zhu, J.-F. Study on antimicrobial activity of chitosan with different molecular weights. Carbohydr. Polym. 2003, 54, 527–530. [Google Scholar] [CrossRef]
  45. No, H.K.; Park, N.Y.; Lee, S.H.; Meyers, S.P. Antibacterial activity of chitosans and chitosan oligomers with different molecular weights. Int. J. Food Microbiol. 2002, 74, 65–72. [Google Scholar] [CrossRef]
  46. Shelma, R.; Sharma, C.P. Acyl modified chitosan derivatives for oral delivery of insulin and curcumin. J. Mater. Sci. Mater. Med. 2010, 21, 2133–2140. [Google Scholar] [CrossRef] [PubMed]
  47. Wu, M.; Long, Z.; Xiao, H.; Dong, C. Preparation of N, N, N-trimethyl chitosan via a novel approach using dimethyl carbonate. Carbohydr. Polym. 2017, 169, 83–91. [Google Scholar] [CrossRef] [PubMed]
  48. Jagadish, R.S.; Divyashree, K.N.; Viswanath, P.; Srinivas, P.; Raj, B. Preparation of N-vanillyl chitosan and 4-hydroxybenzyl chitosan and their physico-mechanical, optical, barrier, and antimicrobial properties. Carbohydr. Polym. 2012, 87, 110–116. [Google Scholar] [CrossRef]
  49. Jeong, Y.-I.; Kim, D.-G.; Jang, M.-K.; Nah, J.-W. Preparation and spectroscopic characterization of methoxy poly(ethylene glycol)-grafted water-soluble chitosan. Carbohydr. Res. 2008, 343, 282–289. [Google Scholar] [CrossRef]
  50. Mohamed, N.A.; Abd El-Ghany, N.A. Preparation and antimicrobial activity of some carboxymethyl chitosan acyl thiourea derivatives. Int. J. Biol. Macromol. 2012, 50, 1280–1285. [Google Scholar] [CrossRef]
  51. Botelho da Silva, S.; Krolicka, M.; van den Broek, L.A.M.; Frissen, A.E.; Boeriu, C.G. Water-soluble chitosan derivatives and pH-responsive hydrogels by selective C-6 oxidation mediated by TEMPO-laccase redox system. Carbohydr. Polym. 2018, 186, 299–309. [Google Scholar] [CrossRef]
  52. Fu, Y.; Xiao, C.; Liu, J. Facile fabrication of quaternary water soluble chitosan-sodium alginate gel and its affinity characteristic toward multivalent metal ion. Environ. Technol. Innov. 2019, 13, 340–345. [Google Scholar] [CrossRef]
  53. Alfaro, L.; Chotiko, A.; Chouljenko, A.; Janes, M.; King, J.M.; Sathivel, S. Development of water-soluble chitosan powder and its antimicrobial effect against inoculated Listeria innocua NRRL B-33016 on shrimp. Food Control 2018, 85, 453–458. [Google Scholar] [CrossRef]
  54. Chouljenko, A.; Chotiko, A.; Reyes, V.; Alfaro, L.; Liu, C.; Dzandu, B.; Sathivel, S. Application of water-soluble chitosan to shrimp for quality retention. LWT 2016, 74, 571–579. [Google Scholar] [CrossRef]
  55. Allan, C.R.; Hadwiger, L.A. The fungicidal effect of chitosan on fungi of varying cell wall composition. Exp. Mycol. 1979, 3, 285–287. [Google Scholar] [CrossRef]
  56. Sarwar, A.; Katas, H.; Zin, N.M. Antibacterial effects of chitosan–tripolyphosphate nanoparticles: Impact of particle size molecular weight. J. Nanoparticle Res. 2014, 16, 2517. [Google Scholar] [CrossRef]
  57. Xing, K.; Chen, X.G.; Kong, M.; Liu, C.S.; Cha, D.S.; Park, H.J. Effect of oleoyl-chitosan nanoparticles as a novel antibacterial dispersion system on viability, membrane permeability and cell morphology of Escherichia coli and Staphylococcus aureus. Carbohydr. Polym. 2009, 76, 17–22. [Google Scholar] [CrossRef]
  58. Ma, Z.; Garrido-Maestu, A.; Jeong, K.C. Application, mode of action, and in vivo activity of chitosan and its micro- and nanoparticles as antimicrobial agents: A review. Carbohydr. Polym. 2017, 176, 257–265. [Google Scholar] [CrossRef]
  59. Tamara, F.; Lin, C.; Mi, F.-L.; Ho, Y.-C. Antibacterial Effects of Chitosan/Cationic Peptide Nanoparticles. Nanomaterials 2018, 8, 88. [Google Scholar] [CrossRef]
  60. Liu, H.; Du, Y.; Wang, X.; Sun, L. Chitosan kills bacteria through cell membrane damage. Int. J. Food Microbiol. 2004, 95, 147–155. [Google Scholar] [CrossRef]
  61. Li, X.; Feng, X.; Yang, S.; Fu, G.; Wang, T.; Su, Z. Chitosan kills Escherichia coli through damage to be of cell membrane mechanism. Carbohydr. Polym. 2010, 79, 493–499. [Google Scholar] [CrossRef]
  62. Ataei, S.; Khorasani, S.N.; Neisiany, R.E. Biofriendly vegetable oil healing agents used for developing self-healing coatings: A review. Prog. Org. Coat. 2019, 129, 77–95. [Google Scholar] [CrossRef]
  63. Scheiner, M.; Dickens, T.J.; Okoli, O. Progress towards self-healing polymers for composite structural applications. Polymer 2016, 83, 260–282. [Google Scholar] [CrossRef]
  64. Garcia, S.J. Effect of polymer architecture on the intrinsic self-healing character of polymers. Eur. Polym. J. 2014, 53, 118–125. [Google Scholar] [CrossRef] [Green Version]
  65. Mauldin, T.C.; Kessler, M.R. Self-healing polymers and composites. Int. Mater. Rev. 2010, 55, 317–346. [Google Scholar] [CrossRef]
  66. Szabó, T.; Molnár-Nagy, L.; Bognár, J.; Nyikos, L.; Telegdi, J. Self-healing microcapsules and slow release microspheres in paints. Prog. Org. Coat. 2011, 72, 52–57. [Google Scholar] [CrossRef]
  67. Hefni, H.H.H.; Azzam, E.M.; Badr, E.A.; Hussein, M.; Tawfik, S.M. Synthesis, characterization and anticorrosion potentials of chitosan-g-PEG assembled on silver nanoparticles. Int. J. Biol. Macromol. 2016, 83, 297–305. [Google Scholar] [CrossRef] [PubMed]
  68. Carneiro, J.; Tedim, J.; Fernandes, S.C.M.; Freire, C.S.R.; Silvestre, A.J.D.; Gandini, A.; Ferreira, M.G.S.; Zheludkevich, M.L. Chitosan-based self-healing protective coatings doped with cerium nitrate for corrosion protection of aluminum alloy 2024. Progr. Org. Coat. 2012, 75, 8–13. [Google Scholar] [CrossRef]
  69. Bao, Q.; Zhang, D.; Wan, Y. 2-Mercaptobenzothiazole doped chitosan/11-alkanethiolate acid composite coating: Dual function for copper protection. Appl. Surface Sci. 2011, 257, 10529–10534. [Google Scholar] [CrossRef]
  70. Ulaeto, S.B.; Pancrecious, J.K.; Rajan, T.P.D.; Pai, B.C. Chapter 17—Smart Coatings. In Noble Metal-Metal Oxide Hybrid Nanoparticles; Mohapatra, S., Nguyen, T.A., Nguyen-Tri, P., Eds.; Woodhead Publishing: Duxford, UK, 2019; pp. 341–372. [Google Scholar]
  71. Carneiro, J.; Tedim, J.; Fernandes, S.C.M.; Freire, C.S.R.; Gandini, A.; Ferreira, M.G.S.; Zheludkevich, M.L. Functionalized chitosan-based coatings for active corrosion protection. Surface Coat. Technol. 2013, 226, 51–59. [Google Scholar] [CrossRef]
  72. Mohandas, A.; Deepthi, S.; Biswas, R.; Jayakumar, R. Chitosan based metallic nanocomposite scaffolds as antimicrobial wound dressings. Bioact. Mater. 2018, 3, 267–277. [Google Scholar] [CrossRef]
  73. Ding, F.; Li, H.; Du, Y.; Shi, X. Recent advances in chitosan-based self-healing materials. Res. Che. Intermed. 2018, 44, 4827–4840. [Google Scholar] [CrossRef]
  74. Zheludkevich, M.L.; Tedim, J.; Freire, C.S.R.; Fernandes, S.C.M.; Kallip, S.; Lisenkov, A.; Gandini, A.; Ferreira, M.G.S. Self-healing protective coatings with “green” chitosan based pre-layer reservoir of corrosion inhibitor. J. Mater. Chem. 2011, 21, 4805. [Google Scholar] [CrossRef]
  75. Wu, Y.; Zheng, Y.; Yang, W.; Wang, C.; Hu, J.; Fu, S. Synthesis and characterization of a novel amphiphilic chitosan–polylactide graft copolymer. Carbohydr. Polym. 2005, 59, 165–171. [Google Scholar] [CrossRef]
  76. Wong, K.; Sun, G.; Zhang, X.; Dai, H.; Liu, Y.; He, C.; Leong, K.W. PEI-g-chitosan, a Novel Gene Delivery System with Transfection Efficiency Comparable to Polyethylenimine in vitro and after Liver Administration in vivo. Bioconjugate Chem. 2006, 17, 152–158. [Google Scholar] [CrossRef] [PubMed]
  77. Kumar, S.; Bhattacharya, W.; Singh, M.; Halder, D.; Mitra, A. Plant latex capped colloidal silver nanoparticles: A potent anti-biofilm and fungicidal formulation. J. Mol. Liq. 2017, 230, 705–713. [Google Scholar] [CrossRef]
  78. Kumari, R.; Brahma, G.; Rajak, S.; Singh, M.; Kumar, S. Antimicrobial activity of green silver nanoparticles produced using aqueous leaf extract of Hydrocotyle rotundifolia. Orient. Pharm. Exp. Med. 2016, 16, 195–201. [Google Scholar] [CrossRef]
  79. Swargiary, M.; Kumar, S. One pot phytosynthesis of gold nanoparticles using aqueous extract of elephant apple- an eco-friendly approach. Orient. Pharm. Exp. Med. 2017, 17, 285–289. [Google Scholar] [CrossRef]
  80. Pang, X.; Zhitomirsky, I. Electrodeposition of hydroxyapatite–silver–chitosan nanocomposite coatings. Surface Coat. Technol. 2008, 202, 3815–3821. [Google Scholar] [CrossRef]
  81. Mishra, S.K.; Ferreira, J.M.F.; Kannan, S. Mechanically stable antimicrobial chitosan–PVA–silver nanocomposite coatings deposited on titanium implants. Carbohydr. Polym. 2015, 121, 37–48. [Google Scholar] [CrossRef]
  82. Pounraj, S.; Somu, P.; Paul, S. Chitosan and graphene oxide hybrid nanocomposite film doped with silver nanoparticles efficiently prevents biofouling. Appl. Surface Sci. 2018, 452, 487–497. [Google Scholar] [CrossRef]
  83. Lin, B.; Luo, Y.; Teng, Z.; Zhang, B.; Zhou, B.; Wang, Q. Development of silver/titanium dioxide/chitosan adipate nanocomposite as an antibacterial coating for fruit storage. LWT-Food Sci. Technol. 2015, 63, 1206–1213. [Google Scholar] [CrossRef]
  84. Ortiz-Duarte, G.; Pérez-Cabrera, L.E.; Artés-Hernández, F.; Martínez-Hernández, G.B. Ag-chitosan nanocomposites in edible coatings affect the quality of fresh-cut melon. Postharvest Biol. Technol. 2019, 147, 174–184. [Google Scholar] [CrossRef]
  85. Al-Naamani, L.; Dobretsov, S.; Dutta, J. Chitosan-zinc oxide nanoparticle composite coating for active food packaging applications. Innov. Food Sci. Emerg. Technol. 2016, 38, 231–237. [Google Scholar] [CrossRef]
  86. Al-Naamani, L.; Dobretsov, S.; Dutta, J.; Burgess, J.G. Chitosan-zinc oxide nanocomposite coatings for the prevention of marine biofouling. Chemosphere 2017, 168, 408–417. [Google Scholar] [CrossRef] [PubMed]
  87. Roosen, J.; Spooren, J.; Binnemans, K. Adsorption performance of functionalized chitosan–silica hybrid materials toward rare earths. J. Mater. Chem. A 2014, 2, 19415–19426. [Google Scholar] [CrossRef]
  88. Grande, C.D.; Mangadlao, J.; Fan, J.; De Leon, A.; Delgado-Ospina, J.; Rojas, J.G.; Rodrigues, D.F.; Advincula, R. Chitosan Cross-Linked Graphene Oxide Nanocomposite Films with Antimicrobial Activity for Application in Food Industry. Macromol. Symp. 2017, 374, 1600114. [Google Scholar] [CrossRef]
  89. Yan, H.; Yang, H.; Li, A.; Cheng, R. pH-tunable surface charge of chitosan/graphene oxide composite adsorbent for efficient removal of multiple pollutants from water. Chem. Eng. J. 2016, 284, 1397–1405. [Google Scholar] [CrossRef]
  90. Dong, X.; Wei, C.; Liang, J.; Liu, T.; Kong, D.; Lv, F. Thermosensitive hydrogel loaded with chitosan-carbon nanotubes for near infrared light triggered drug delivery. Colloids Surfaces B Biointerfaces 2017, 154, 253–262. [Google Scholar] [CrossRef]
  91. Papadimitriou, L.; Kaliva, M.; Vamvakaki, M.; Chatzinikolaidou, M. Immunomodulatory Potential of Chitosan-graft-poly(ε-caprolactone) Copolymers toward the Polarization of Bone-Marrow-Derived Macrophages. ACS Biomater. Sci. Eng. 2017, 3, 1341–1349. [Google Scholar] [CrossRef]
  92. Pandiyaraj, K.N.; Ramkumar, M.C.; Arun Kumar, A.; Padmanabhan, P.V.A.; Pichumani, M.; Bendavid, A.; Cools, P.; De Geyter, N.; Morent, R.; Kumar, V.; et al. Evaluation of surface properties of low density polyethylene (LDPE) films tailored by atmospheric pressure non-thermal plasma (APNTP) assisted co-polymerization and immobilization of chitosan for improvement of antifouling properties. Mater. Sci. Eng. C 2019, 94, 150–160. [Google Scholar] [CrossRef]
  93. Trivedi, P.; Saloranta-Simell, T.; Maver, U.; Gradišnik, L.; Prabhakar, N.; Smått, J.-H.; Mohan, T.; Gericke, M.; Heinze, T.; Fardim, P. Chitosan–Cellulose Multifunctional Hydrogel Beads: Design, Characterization and Evaluation of Cytocompatibility with Breast Adenocarcinoma and Osteoblast Cells. Bioengineering 2018, 5, 3. [Google Scholar] [CrossRef] [PubMed]
  94. Wang, Z.; Shi, Y.; Yang, X.; Xiong, Y.; Li, Y.; Chen, B.; Lai, W.-F.; Rogach, A.L. Water-Soluble Biocompatible Copolymer Hypromellose Grafted Chitosan Able to Load Exogenous Agents and Copper Nanoclusters with Aggregation-Induced Emission. Adv. Funct. Mater. 2018, 28, 1802848. [Google Scholar] [CrossRef]
  95. Wang, G.; Wang, X.; Huang, L. Feasibility of chitosan-alginate (Chi-Alg) hydrogel used as scaffold for neural tissue engineering: A pilot study in vitro. Biotechnol. Biotechnol. Equip. 2017, 31, 766–773. [Google Scholar] [CrossRef]
  96. Njoku, D.I.; Cui, M.; Xiao, H.; Shang, B.; Li, Y. Understanding the anticorrosive protective mechanisms of modified epoxy coatings with improved barrier, active and self-healing functionalities: EIS and spectroscopic techniques. Sci. Rep. 2017, 7, 15597. [Google Scholar] [CrossRef]
  97. Benucci, I.; Liburdi, K.; Cacciotti, I.; Lombardelli, C.; Zappino, M.; Nanni, F.; Esti, M. Chitosan/clay nanocomposite films as supports for enzyme immobilization: An innovative green approach for winemaking applications. Food Hydrocoll. 2018, 74, 124–131. [Google Scholar] [CrossRef]
  98. Azharul Islam, M.; Tan, Y.L.; Atikul Islam, M.; Romić, M.; Hameed, B.H. Chitosan–bleaching earth clay composite as an efficient adsorbent for carbon dioxide adsorption: Process optimization. Colloids Surfaces A Physicochem. Eng. Asp. 2018, 554, 9–15. [Google Scholar] [CrossRef]
  99. Li, X.; Li, Y.-C.; Chen, M.; Shi, Q.; Sun, R.; Wang, X. Chitosan/rectorite nanocomposite with injectable functionality for skin hemostasis. J. Mater. Chem. B 2018, 6, 6544–6549. [Google Scholar] [CrossRef]
  100. Susilowati, E.; MaryaniAshadi, *!!! REPLACE !!!*. Preparation of silver-chitosan nanocomposites and coating on bandage for antibacterial wound dressing application. AIP Conf. Proc. 2016, 1710, 030015. [Google Scholar]
  101. El-Sherbiny, I.M.; Hefnawy, A.; Salih, E. New core–shell hyperbranched chitosan-based nanoparticles as optical sensor for ammonia detection. Int. J. Biol. Macromol. 2016, 86, 782–788. [Google Scholar] [CrossRef]
  102. Ogugbue, C.J.; Sawidis, T. Bioremediation and Detoxification of Synthetic Wastewater Containing Triarylmethane Dyes by Aeromonas hydrophila Isolated from Industrial Effluent. Biotechnol. Res. Int. 2011, 2011, 1–11. [Google Scholar] [CrossRef]
  103. Brüschweiler, B.J. Toxicity of non-regulated aromatic amines from azo dyes in textiles: Knowns and unknowns. Toxicol. Lett. 2013, 221, S54. [Google Scholar] [CrossRef]
  104. Wang, J.; Zhuang, S. Removal of various pollutants from water and wastewater by modified chitosan adsorbents. Crit. Rev. Environ. Sci. Technol. 2017, 47, 2331–2386. [Google Scholar] [CrossRef]
  105. Shen, C.; Shen, Y.; Wen, Y.; Wang, H.; Liu, W. Fast and highly efficient removal of dyes under alkaline conditions using magnetic chitosan-Fe(III) hydrogel. Water Res. 2011, 45, 5200–5210. [Google Scholar] [CrossRef] [PubMed]
  106. Ali, F.; Khan, S.B.; Kamal, T.; Anwar, Y.; Alamry, K.A.; Asiri, A.M. Anti-bacterial chitosan/zinc phthalocyanine fibers supported metallic and bimetallic nanoparticles for the removal of organic pollutants. Carbohydr. Polym. 2017, 173, 676–689. [Google Scholar] [CrossRef] [PubMed]
  107. Nithya, A.; JeevaKumari, H.L.; Rokesh, K.; Ruckmani, K.; Jeganathan, K.; Jothivenkatachalam, K. A versatile effect of chitosan-silver nanocomposite for surface plasmonic photocatalytic and antibacterial activity. J. Photochem. Photobiol. B Biol. 2015, 153, 412–422. [Google Scholar] [CrossRef] [PubMed]
  108. Ramirez, O.; Bonardd, S.; Saldías, C.; Radic, D.; Leiva, Á. Biobased Chitosan Nanocomposite Films Containing Gold Nanoparticles: Obtainment, Characterization, and Catalytic Activity Assessment. ACS Appl. Mater. Interfaces 2017, 9, 16561–16570. [Google Scholar] [CrossRef] [PubMed]
  109. Karthikeyan, K.T.; Nithya, A.; Jothivenkatachalam, K. Photocatalytic and antimicrobial activities of chitosan-TiO2 nanocomposite. Int. J. Biol. Macromol. 2017, 104, 1762–1773. [Google Scholar] [CrossRef] [PubMed]
  110. Rasoulifard, M.H.; Seyed Dorraji, M.S.; Amani-Ghadim, A.R.; Keshavarz-babaeinezhad, N. Visible-light photocatalytic activity of chitosan/polyaniline/CdS nanocomposite: Kinetic studies and artificial neural network modeling. Appl. Catal. A Gen. 2016, 514, 60–70. [Google Scholar] [CrossRef]
  111. Kumar, S.; Krishnakumar, B.; Sobral, A.J.F.N.; Koh, J. Bio-based (chitosan/PVA/ZnO) nanocomposites film: Thermally stable and photoluminescence material for removal of organic dye. Carbohydr. Polym. 2019, 205, 559–564. [Google Scholar] [CrossRef] [PubMed]
  112. Abbasi, M. Synthesis and characterization of magnetic nanocomposite of chitosan/SiO2/carbon nanotubes and its application for dyes removal. J. Clean. Prod. 2017, 145, 105–113. [Google Scholar] [CrossRef]
  113. Masilompane, T.M.; Chaukura, N.; Mishra, S.B.; Mishra, A.K. Chitosan-lignin-titania nanocomposites for the removal of brilliant black dye from aqueous solution. Int. J. Biol. Macromol. 2018, 120, 1659–1666. [Google Scholar] [CrossRef] [PubMed]
  114. Darvishi Cheshmeh Soltani, R.; Khataee, A.R.; Safari, M.; Joo, S.W. Preparation of bio-silica/chitosan nanocomposite for adsorption of a textile dye in aqueous solutions. Int. Biodeterior. Biodegrad. 2013, 85, 383–391. [Google Scholar] [CrossRef]
  115. Dhanavel, S.; Manivannan, N.; Mathivanan, N.; Gupta, V.K.; Narayanan, V.; Stephen, A. Preparation and characterization of cross-linked chitosan/palladium nanocomposites for catalytic and antibacterial activity. J. Mol. Liq. 2018, 257, 32–41. [Google Scholar] [CrossRef]
  116. Gupta, V.K.; Saravanan, R.; Agarwal, S.; Gracia, F.; Khan, M.M.; Qin, J.; Mangalaraja, R.V. Degradation of azo dyes under different wavelengths of UV light with chitosan-SnO2 nanocomposites. J. Mol. Liq. 2017, 232, 423–430. [Google Scholar] [CrossRef]
  117. Cao, Q.; Xiao, L.; Zeng, L.; Cao, C.; Wang, J. Ag3PO4/chitosan/CdS nanocomposites exhibiting high photocatalytic activities under visible-light illumination. Powder Technol. 2017, 321, 1–8. [Google Scholar] [CrossRef]
  118. Vanamudan, A.; Sadhu, M.; Pamidimukkala, P.S. Nanostructured zirconium tungstate and its bionanocomposite with chitosan: Wet peroxide photocatalytic degradation of dyes. J. Taiwan Inst. Chem. Eng. 2018, 85, 74–82. [Google Scholar] [CrossRef]
  119. Karpuraranjith, M.; Thambidurai, S. Biotemplate-SnO2 particles intercalated PANI matrix: Enhanced photo catalytic activity for degradation of MB and RY-15 dye. Polym. Degrad. Stab. 2016, 133, 108–118. [Google Scholar] [CrossRef]
  120. Ali, F.; Khan, S.B.; Kamal, T.; Alamry, K.A.; Asiri, A.M. Chitosan-titanium oxide fibers supported zero-valent nanoparticles: Highly efficient and easily retrievable catalyst for the removal of organic pollutants. Sci. Rep. 2018, 8, 6260. [Google Scholar] [CrossRef]
  121. Ali, F.; Khan, S.B.; Kamal, T.; Alamry, K.A.; Asiri, A.M.; Sobahi, T.R.A. Chitosan coated cotton cloth supported zero-valent nanoparticles: Simple but economically viable, efficient and easily retrievable catalysts. Sci. Rep. 2017, 7, 16957. [Google Scholar] [CrossRef]
  122. Magesan, P.; Sanuja, S.; Umapathy, M.J. Novel hybrid chitosan blended MoO3–TiO2 nanocomposite film: Evaluation of its solar light photocatalytic and antibacterial activities. RSC Adv. 2015, 5, 42506–42515. [Google Scholar] [CrossRef]
  123. Zhou, J.; Lü, Q.-F.; Luo, J.-J. Efficient removal of organic dyes from aqueous solution by rapid adsorption onto polypyrrole–based composites. J. Clean. Prod. 2017, 167, 739–748. [Google Scholar] [CrossRef]
  124. Wahl, M. Marine epibiosis. I. Fouling and antifouling: Some basic aspects. Mar. Ecol. Progr. Ser. 1989, 58, 175–189. [Google Scholar] [CrossRef]
  125. Qian, P.Y.; Lau, S.C.K.; Dahms, H.U.; Dobretsov, S.; Harder, T. Marine Biofilms as Mediators of Colonization by Marine Macroorganisms: Implications for Antifouling and Aquaculture. Mar. Biotechnol. 2007, 9, 399–410. [Google Scholar] [CrossRef] [PubMed]
  126. Salta, M.; Wharton, J.A.; Blache, Y.; Stokes, K.R.; Briand, J.-F. Marine biofilms on artificial surfaces: Structure and dynamics. Environ. Microbiol. 2013, 15, 2879–2893. [Google Scholar] [CrossRef] [PubMed]
  127. Yebra, D.M.; Kiil, S.; Dam-Johansen, K. Antifouling technology—Past, present and future steps towards efficient and environmentally friendly antifouling coatings. Progr. Org. Coat. 2004, 50, 75–104. [Google Scholar] [CrossRef]
  128. Schultz, M.P.; Bendick, J.A.; Holm, E.R.; Hertel, W.M. Economic impact of biofouling on a naval surface ship. Biofouling 2010, 27, 87–98. [Google Scholar] [CrossRef] [PubMed]
  129. Pelletier, É.; Bonnet, C.; Lemarchand, K. Biofouling Growth in Cold Estuarine Waters and Evaluation of Some Chitosan and Copper Anti-Fouling Paints. Int. J. Mol. Sci. 2009, 10, 3209–3223. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  130. Al-Naamani, L.S. Antifouling properties of chitosan coatings on plastic substrates. J. Agric. Mar. Sci. [JAMS] 2019, 23, 92. [Google Scholar] [CrossRef]
  131. Dobretsov, S.; Abed, R.M.M.; Muthukrishnan, T.; Sathe, P.; Al-Naamani, L.; Queste, B.Y.; Piontkovski, S. Living on the edge: Biofilms developing in oscillating environmental conditions. Biofouling 2018, 34, 1064–1077. [Google Scholar] [CrossRef]
  132. Thomas, V.; Yallapu, M.M.; Sreedhar, B.; Bajpai, S.K. Fabrication, Characterization of Chitosan/Nanosilver Film and Its Potential Antibacterial Application. J. Biomater. Sci. Polym. Ed. 2009, 20, 2129–2144. [Google Scholar] [CrossRef]
  133. Reighard, K.P.; Hill, D.B.; Dixon, G.A.; Worley, B.V.; Schoenfisch, M.H. Disruption and eradication of P. aeruginosabiofilms using nitric oxide-releasing chitosan oligosaccharides. Biofouling 2015, 31, 775–787. [Google Scholar] [CrossRef] [PubMed]
  134. Elshaarawy, R.F.M.; Mustafa, F.H.A.; van Geelen, L.; Abou-Taleb, A.E.A.; Tadros, H.R.Z.; Kalscheuer, R.; Janiak, C. Mining marine shell wastes for polyelectrolyte chitosan anti-biofoulants: Fabrication of high-performance economic and ecofriendly anti-biofouling coatings. Carbohydr. Polym. 2017, 172, 352–364. [Google Scholar] [CrossRef] [PubMed]
  135. Takahashi, T.; Imai, M.; Suzuki, I.; Sawai, J. Growth inhibitory effect on bacteria of chitosan membranes regulated with deacetylation degree. Biochem. Eng. J. 2008, 40, 485–491. [Google Scholar] [CrossRef]
  136. Nigmatullin, R.; Konovalova, V.; Pobigay, G. Development of antimicrobial membranes via the surface tethering of chitosan. J. Appl. Polym. Sci. 2009, 111, 1697–1705. [Google Scholar] [CrossRef]
  137. Salehi, H.; Rastgar, M.; Shakeri, A. Anti-fouling and high water permeable forward osmosis membrane fabricated via layer by layer assembly of chitosan/graphene oxide. Appl. Surface Sci. 2017, 413, 99–108. [Google Scholar] [CrossRef]
  138. Bulwan, M.; Wójcik, K.; Zapotoczny, S.; Nowakowska, M. Chitosan-Based Ultrathin Films as Antifouling, Anticoagulant and Antibacterial Protective Coatings. J. Biomater. Sci. Polym. Ed. 2012, 23, 1963–1980. [Google Scholar] [CrossRef]
  139. Shanthana Lakshmi, D.; Jaiswar, S.; saxena, M.; Tasselli, F.; Raval, H.D. Preparation and performance of biofouling resistant PAN/chitosan hollow fiber membranes. 3 Biotech 2017, 7, 224. [Google Scholar] [CrossRef]
  140. Zinadini, S.; Zinatizadeh, A.A.; Rahimi, M.; Vatanpour, V.; Zangeneh, H.; Beygzadeh, M. Novel high flux antifouling nanofiltration membranes for dye removal containing carboxymethyl chitosan coated Fe3O4 nanoparticles. Desalination 2014, 349, 145–154. [Google Scholar] [CrossRef]
  141. Wang, R.; Song, X.; Xiang, T.; Liu, Q.; Su, B.; Zhao, W.; Zhao, C. Mussel-inspired chitosan-polyurethane coatings for improving the antifouling and antibacterial properties of polyethersulfone membranes. Carbohydr. Polym. 2017, 168, 310–319. [Google Scholar] [CrossRef]
  142. Yousuf, B.; Qadri, O.S.; Srivastava, A.K. Recent developments in shelf-life extension of fresh-cut fruits and vegetables by application of different edible coatings: A review. LWT 2018, 89, 198–209. [Google Scholar] [CrossRef]
  143. Gong, T.; Li, C.; Bian, B.; Wu, Y.; Dawuda, M.M.; Liao, W. Advances in application of small molecule compounds for extending the shelf life of perishable horticultural products: A review. Sci. Hortic. 2018, 230, 25–34. [Google Scholar] [CrossRef]
  144. Swaminathan, M.S. Food Losses and Food Waste. In Combating Hunger and Achieving Food Security; Cambridge University Press: Cambridge, UK, 2015; pp. 37–46. [Google Scholar]
  145. Ma, L.; Zhang, M.; Bhandari, B.; Gao, Z. Recent developments in novel shelf life extension technologies of fresh-cut fruits and vegetables. Trends Food Sci. Technol. 2017, 64, 23–38. [Google Scholar] [CrossRef] [Green Version]
  146. Yuan, G.; Chen, X.; Li, D. Chitosan films and coatings containing essential oils: The antioxidant and antimicrobial activity, and application in food systems. Food Res. Int. 2016, 89, 117–128. [Google Scholar] [CrossRef]
  147. Zhang, X.; Xiao, G.; Wang, Y.; Zhao, Y.; Su, H.; Tan, T. Preparation of chitosan-TiO2 composite film with efficient antimicrobial activities under visible light for food packaging applications. Carbohydr. Polym. 2017, 169, 101–107. [Google Scholar] [CrossRef]
  148. Shankar, S.; Rhim, J.-W. Preparation of sulfur nanoparticle-incorporated antimicrobial chitosan films. Food Hydrocoll. 2018, 82, 116–123. [Google Scholar] [CrossRef]
  149. Xu, D.A.N.; Qin, H.-R.; Ren, D.A.N.; Yu, Y.-L. Influence of Coating Time on the Preservation Performance of Chitosan/Montmorillonite Composite Coating on Tangerine Fruits. In The 21st IAPRI World Conference on Packaging; DEStech Publications, Inc.: Zhuhai, China, 2018. [Google Scholar]
  150. Cosme Silva, G.M.; Silva, W.B.; Medeiros, D.B.; Salvador, A.R.; Cordeiro, M.H.M.; da Silva, N.M.; Santana, D.B.; Mizobutsi, G.P. The chitosan affects severely the carbon metabolism in mango (Mangifera indica L. cv. Palmer) fruit during storage. Food Chem. 2017, 237, 372–378. [Google Scholar] [CrossRef]
  151. Salari, M.; Sowti Khiabani, M.; Rezaei Mokarram, R.; Ghanbarzadeh, B.; Samadi Kafil, H. Development and evaluation of chitosan based active nanocomposite films containing bacterial cellulose nanocrystals and silver nanoparticles. Food Hydrocoll. 2018, 84, 414–423. [Google Scholar] [CrossRef]
  152. Naskar, A.; Khan, H.; Sarkar, R.; Kumar, S.; Halder, D.; Jana, S. Anti-biofilm activity and food packaging application of room temperature solution process based polyethylene glycol capped Ag-ZnO-graphene nanocomposite. Mater. Sci. Eng. C 2018, 91, 743–753. [Google Scholar] [CrossRef]
  153. Kanmani, P.; Rhim, J.-W. Physical, mechanical and antimicrobial properties of gelatin based active nanocomposite films containing AgNPs and nanoclay. Food Hydrocoll. 2014, 35, 644–652. [Google Scholar] [CrossRef]
  154. Youssef, A.M.; El-Sayed, S.M. Bionanocomposites materials for food packaging applications: Concepts and future outlook. Carbohydr. Polym. 2018, 193, 19–27. [Google Scholar] [CrossRef]
  155. Kumar, S.; Shukla, A.; Baul, P.P.; Mitra, A.; Halder, D. Biodegradable hybrid nanocomposites of chitosan/gelatin and silver nanoparticles for active food packaging applications. Food Packag. Shelf Life 2018, 16, 178–184. [Google Scholar] [CrossRef]
  156. Basumatary, K.; Daimary, P.; Das, S.K.; Thapa, M.; Singh, M.; Mukherjee, A.; Kumar, S. Lagerstroemia speciosa fruit-mediated synthesis of silver nanoparticles and its application as filler in agar based nanocomposite films for antimicrobial food packaging. Food Packag. Shelf Life 2018, 17, 99–106. [Google Scholar] [CrossRef]
  157. Kumar, S.; Mitra, A.; Halder, D. Centella asiatica leaf mediated synthesis of silver nanocolloid and its application as filler in gelatin based antimicrobial nanocomposite film. LWT 2017, 75, 293–300. [Google Scholar] [CrossRef]
  158. Al-Naamani, L.; Dutta, J.; Dobretsov, S. Nanocomposite Zinc Oxide-Chitosan Coatings on Polyethylene Films for Extending Storage Life of Okra (Abelmoschus esculentus). Nanomaterials 2018, 8, 479. [Google Scholar] [CrossRef]
  159. Kaewklin, P.; Siripatrawan, U.; Suwanagul, A.; Lee, Y.S. Active packaging from chitosan-titanium dioxide nanocomposite film for prolonging storage life of tomato fruit. Int. J. Biol. Macromol. 2018, 112, 523–529. [Google Scholar] [CrossRef]
  160. Mujeeb Rahman, P.; Abdul Mujeeb, V.M.; Muraleedharan, K.; Thomas, S.K. Chitosan/nano ZnO composite films: Enhanced mechanical, antimicrobial and dielectric properties. Arab. J. Chem. 2018, 11, 120–127. [Google Scholar] [CrossRef] [Green Version]
  161. Saral Sarojini, K.; Indumathi, M.P.; Rajarajeswari, G.R. Mahua oil-based polyurethane/chitosan/nano ZnO composite films for biodegradable food packaging applications. Int. J. Biol. Macromol. 2019, 124, 163–174. [Google Scholar]
  162. Chutichude, B.; Chutichude, P. Effects of Chitosan Coating to Some Postharvest Characteristics of Hylocercus undatus (Haw) Brit. and Rose Fruit. Int. J. Agric. Res. 2011, 6, 82–92. [Google Scholar] [CrossRef]
  163. Lin, B.; Du, Y.; Liang, X.; Wang, X.; Wang, X.; Yang, J. Effect of chitosan coating on respiratory behavior and quality of stored litchi under ambient temperature. J. Food Eng. 2011, 102, 94–99. [Google Scholar] [CrossRef]
  164. Kaya, M.; Česonienė, L.; Daubaras, R.; Leskauskaitė, D.; Zabulionė, D. Chitosan coating of red kiwifruit (Actinidia melanandra) for extending of the shelf life. Int. J. Biol. Macromol. 2016, 85, 355–360. [Google Scholar] [CrossRef]
  165. Batista Silva, W.; Cosme Silva, G.M.; Santana, D.B.; Salvador, A.R.; Medeiros, D.B.; Belghith, I.; da Silva, N.M.; Cordeiro, M.H.M.; Misobutsi, G.P. Chitosan delays ripening and ROS production in guava (Psidium guajava L.) fruit. Food Chem. 2018, 242, 232–238. [Google Scholar] [CrossRef]
  166. Drevinskas, T.; Naujokaitytė, G.; Maruška, A.; Kaya, M.; Sargin, I.; Daubaras, R.; Česonienė, L. Effect of molecular weight of chitosan on the shelf life and other quality parameters of three different cultivars of Actinidia kolomikta (kiwifruit). Carbohydr. Polym. 2017, 173, 269–275. [Google Scholar] [CrossRef]
  167. Castelo Branco Melo, N.F.; de MendonçaSoares, B.L.; Marques Diniz, K.; Ferreira Leal, C.; Canto, D.; Flores, M.A.P.; Henrique da Costa Tavares-Filho, J.; Galembeck, A.; Montenegro Stamford, T.L.; Montenegro Stamford-Arnaud, T.; et al. Effects of fungal chitosan nanoparticles as eco-friendly edible coatings on the quality of postharvest table grapes. Postharvest Biol. Technol. 2018, 139, 56–66. [Google Scholar] [CrossRef]
  168. Candir, E.; Ozdemir, A.E.; Aksoy, M.C. Effects of chitosan coating and modified atmosphere packaging on postharvest quality and bioactive compounds of pomegranate fruit cv. ‘Hicaznar’. Sci. Hortic. 2018, 235, 235–243. [Google Scholar] [CrossRef]
  169. Maqbool, M.; Ali, A.; Alderson, P.G.; Zahid, N.; Siddiqui, Y. Effect of a Novel Edible Composite Coating Based on Gum Arabic and Chitosan on Biochemical and Physiological Responses of Banana Fruits during Cold Storage. J. Agric. Food Chem. 2011, 59, 5474–5482. [Google Scholar] [CrossRef]
  170. Özdemir, K.S.; Gökmen, V. Extending the shelf-life of pomegranate arils with chitosan-ascorbic acid coating. LWT-Food Sci. Technol. 2017, 76, 172–180. [Google Scholar] [CrossRef]
  171. Shen, Y.; Yang, H. Effect of preharvest chitosan- g -salicylic acid treatment on postharvest table grape quality, shelf life, and resistance to Botrytis cinerea -induced spoilage. Sci. Hortic. 2017, 224, 367–373. [Google Scholar] [CrossRef]
  172. Eshetu, A.; Ibrahim, A.M.; Forsido, S.F.; Kuyu, C.G. Effect of beeswax and chitosan treatments on quality and shelf life of selected mango (Mangifera indica L.) cultivars. Heliyon 2019, 5, e01116. [Google Scholar] [CrossRef]
  173. Lo’ay, A.A.; Taher, M.A. Influence of edible coatings chitosan/PVP blending with salicylic acid on biochemical fruit skin browning incidence and shelf life of guava fruits cv. ‘Banati’. Sci. Hortic. 2018, 235, 424–436. [Google Scholar] [CrossRef]
  174. Nair, M.S.; Saxena, A.; Kaur, C. Effect of chitosan and alginate based coatings enriched with pomegranate peel extract to extend the postharvest quality of guava (Psidium guajava L.). Food Chem. 2018, 240, 245–252. [Google Scholar] [CrossRef]
  175. Tesfay, S.Z.; Magwaza, L.S. Evaluating the efficacy of moringa leaf extract, chitosan and carboxymethyl cellulose as edible coatings for enhancing quality and extending postharvest life of avocado (Persea americana Mill.) fruit. Food Packag. Shelf Life 2017, 11, 40–48. [Google Scholar] [CrossRef]
  176. Lo’ay, A.A.; Dawood, H.D. Active chitosan/PVA with ascorbic acid and berry quality of ‘Superior seedless’ grapes. Sci. Hortic. 2017, 224, 286–292. [Google Scholar] [CrossRef]
  177. Treviño-Garza, M.Z.; García, S.; Heredia, N.; Alanís-Guzmán, M.G.; Arévalo-Niño, K. Layer-by-layer edible coatings based on mucilages, pullulan and chitosan and its effect on quality and preservation of fresh-cut pineapple (Ananas comosus). Postharvest Biol. Technol. 2017, 128, 63–75. [Google Scholar] [CrossRef]
  178. Xu, D.; Qin, H.; Ren, D. Prolonged preservation of tangerine fruits using chitosan/montmorillonite composite coating. Postharvest Biol. Technol. 2018, 143, 50–57. [Google Scholar] [CrossRef]
  179. Shi, S.; Wang, W.; Liu, L.; Wu, S.; Wei, Y.; Li, W. Effect of chitosan/nano-silica coating on the physicochemical characteristics of longan fruit under ambient temperature. J. Food Eng. 2013, 118, 125–131. [Google Scholar] [CrossRef]
Figure 1. Wide ranging industrial applications of chitosan.
Figure 1. Wide ranging industrial applications of chitosan.
Applsci 09 02409 g001
Figure 2. Chemical structures of chitin and chitosan.
Figure 2. Chemical structures of chitin and chitosan.
Applsci 09 02409 g002
Figure 3. Preparation of chitosan from crustacean wastes.
Figure 3. Preparation of chitosan from crustacean wastes.
Applsci 09 02409 g003
Figure 4. Transmission Electron Micrographs (TEM) of E. coli (a) treated with buffer and (bd) chitosan of 50 kDa molecular weight, (Reproduced with permission from [61], Copyright © 2010, Elsevier).
Figure 4. Transmission Electron Micrographs (TEM) of E. coli (a) treated with buffer and (bd) chitosan of 50 kDa molecular weight, (Reproduced with permission from [61], Copyright © 2010, Elsevier).
Applsci 09 02409 g004
Figure 5. Preservation of red grapes wrapped with (a) polyethylene film, (b) pure chitosan film, and (c) chitosan-TiO2 film, stored at 37 °C for six days. (Reproduced with permission from [147], Copyright © 2017, Elsevier).
Figure 5. Preservation of red grapes wrapped with (a) polyethylene film, (b) pure chitosan film, and (c) chitosan-TiO2 film, stored at 37 °C for six days. (Reproduced with permission from [147], Copyright © 2017, Elsevier).
Applsci 09 02409 g005
Figure 6. Illustration of coatings for improving the shelf-life of fresh produce.
Figure 6. Illustration of coatings for improving the shelf-life of fresh produce.
Applsci 09 02409 g006
Table 4. Chitosan-based antimicrobial films and their properties for the packaging of fruits and vegetables.
Table 4. Chitosan-based antimicrobial films and their properties for the packaging of fruits and vegetables.
CS/CS-Composite FilmCS Concentration in FFS (%, w/v)Nano-Filler Concentration (% w/w of Solid Matter)Food Systems/ApplicationsAntimicrobial Activity (Microorganism Tested)Effect of FilmsThickness, Mechanical and Permeability PropertiesReferences
Thickness (μm)TS (MPa)EAB (%)WVP or WVTR
CS/TiO22.5TiO2-10Red grapesE. coli,
S. aureus,
C. albicans,
A. niger
Red grapes were preserved for 22 days with composite film compared to 15 days with bare chitosan film before mildew occurred7046.33 ± 1.8825.77 ± 2.91No data[147]
CS/TiO22.0TiO2-1.0Tomato fruitNo dataComposite film delayed the ripening process of tomato fruits and loss in qualityNo data16.43 ± 0.4653.06 ± 2.1519.14 ± 1.13 (gm−2d−1)[159]
CS/nano ZnO2.0Zinc acetate-100No dataE. coli,
S. aureus
Composite films showed good antimicrobial activity against both Gram-negative and Gram-positive bacteriaNo data41.73 ± 0.4832.44 ± 0.5222.53 ± 0.31 (g/h m2)[160]
CS/Gelatin/AgNPs1.8AgNPs-0.1Red grapesNo dataShelf-life of red grapes were extended by 14 days compared to control87.60 ± 2.1921.19 ± 1.0127.23 ± 0.76No data[155]
CS/Bacterial cellulose nanocrystals (BCNC)/AgNPs1.0AgNPs-1.0No dataS. aureus,
B. cereus,
E. Coli,
Ps. Aeruginosa,
C. albicans
Addition of BCNC and/or AgNPs in chitosan film improved its physical, mechanical, and antimicrobial properties14042.89 ± 1.7622.50 ± 2.072.16 ± 0.06 (×10−10 g/smPa)[151]
CS/Polyurethane (PU)/nano ZnOCS/PU ratio 0.25:0.75ZnONPs–1.0, 3.0 and 5.0Carrot piecesE. coli,
S. aureus
Composite films efficiently enhanced the shelf-life of carrot pieces by 9 days compared to control1008.12.156163.0 (g/m2/day)[161]
CS/Sulfur nanoparticles (SNP)2.67SNP-2.0No dataE. coli,
L. monocytogenes
Composite films showed high antibacterial activity against foodborne pathogens and could be potentially used in antimicrobial food packaging55.6 ± 4.739.4 ± 4.48.3 ± 3.10.96 ± 0.17 (×10−9 g.m/m2.Pa.s)[148]
Table 5. Chitosan/chitosan-based composite coatings formulations for fruits and vegetables.
Table 5. Chitosan/chitosan-based composite coatings formulations for fruits and vegetables.
Chitosan Based Coating FormulationsChitosan % (w/v)Fruits and Vegetables TypeEffects of CoatingReferences
CS only1.0–3.0Rose or Pitaya fruit (Hylocercus undatus)Coating containing 3% chitosan played the beneficial role for slowing down fruit withering, and maintained the fresh appearance and extended the maximal storability at ambient temperature[162]
CS only1.0Litchi fruitCoating effectively reduced the respiration rate as well as transpiration rate of litchi fruits during storage[163]
CS only1.0Red kiwifruit (Actinidia melanandra)Chitosan coating was found to enhance the shelf-life of kiwifruit[164]
CS only1.0–3.0Mango fruit (Mangifera indica)Coating delayed the climacteric peak, water loss, firmness, and ultimately prolonged the quality attributes of fruit[150]
CS only1.0–3.0Guava fruit (Psidium guajava)Coating effectively maintained the quality of guava fruits by increasing antioxidant value, and delaying ripening of fruits during storage at room temperature[165]
CS only (Low, med, and high molecular weight)1.0Kiwifruit (Actinidia kolomikta)High-molecular-weight chitosan showed more pronounced improvements on the shelf-life of kiwifruit[166]
CS-nanoparticles1.0Table grapesEdible coatings of chitosan nanoparticle efficiently delayed the ripening process and led to reduced weight loss, soluble solids, and sugar contents[167]
CS coating with modified atmosphere packaging (MAP)1.0Pomegranate fruitChitosan coating with MAP treatment led to maintenance of visual quality and initial red aril colour intensity of fruits for up to 6 months under cold storage at 6 °C.[168]
CS/Gum Arabic1.0Banana fruitCoating delayed ripening by decreasing the rate of respiration of fruits and enhanced shelf-life for up to 33 days[169]
CS/Ascorbic acid1.0–2.0Pomegranate arilsShelf-life of arils could be extended to 21 days at 5 °C from 10 days for uncoated arils (control)[170]
CS/g-Salicylic acid1.0Table grapesComposite coatings on grapes improved the post-harvest life by decreasing the rate of respiration, decay incidence, and weight loss, and by maintaining/improving levels of total soluble solids, titratable acidity, and sensory attributes during storage[171]
CS/beeswax1.5–2.0Mango fruit (M. indica)Coating on fruits ultimately maintained firmness and improved shelf-life up to 3 weeks compared to control (uncoated)[172]
CS/ PVP/ Salicylic acid (SA)1.0Guava fruit (P. guajava)Fruits coated with CS/PVP-SA showed minimum loss in water and browning of skin that helped in maintaining fruit colour and firmness[173]
CS/Alginate with Pomegranate peel extract (PPE)1.0Guava fruit (P. guajava)Coatings proved efficient in maintaining the quality of guava for up to 20 days at low temperature storage[174]
CS/CMC/ Moringa leaf extract0.5–1.0Avocado fruit (Persea americana)Coating on fruits efficiently reduced the respiration rate, moisture loss, and firmness that ultimately helps in improving fruit quality and shelf-life[175]
CS/PVA blended with ascorbic acid (AA)N/A‘Superior seedless’ grapesCoating treatment significantly reduced water loss, shattering of berry, and delayed the colour change and titratable acidity[176]
CS/Pullulan, CS/Linseed, CS/Nopal cactus, CS/Aloe mucilage1.5Fresh-cut pineapple (Ananas comosus)Layer-by-layer edible coatings were beneficial to maintain the quality and extension of the shelf-life of cut pineapple[177]
CS/MMT1.5Tangerine fruitsCoated fruit showed reduced decay rate, loss in weight, and improvements in total soluble solids and titratable acidity[178]
CS/nano-silica2.0Longan fruitCoating shown to improve the quality of longan fruits for the period of extended storage[179]
CS-AgNPs1.0Fresh-cut melonCoatings decreased the rate of respiration and rate of production of ethylene compared to uncoated samples and thus had better sensory quality up to 13 days at 5 °C[84]

Share and Cite

MDPI and ACS Style

Kumar, S.; Ye, F.; Dobretsov, S.; Dutta, J. Chitosan Nanocomposite Coatings for Food, Paints, and Water Treatment Applications. Appl. Sci. 2019, 9, 2409. https://doi.org/10.3390/app9122409

AMA Style

Kumar S, Ye F, Dobretsov S, Dutta J. Chitosan Nanocomposite Coatings for Food, Paints, and Water Treatment Applications. Applied Sciences. 2019; 9(12):2409. https://doi.org/10.3390/app9122409

Chicago/Turabian Style

Kumar, Santosh, Fei Ye, Sergey Dobretsov, and Joydeep Dutta. 2019. "Chitosan Nanocomposite Coatings for Food, Paints, and Water Treatment Applications" Applied Sciences 9, no. 12: 2409. https://doi.org/10.3390/app9122409

APA Style

Kumar, S., Ye, F., Dobretsov, S., & Dutta, J. (2019). Chitosan Nanocomposite Coatings for Food, Paints, and Water Treatment Applications. Applied Sciences, 9(12), 2409. https://doi.org/10.3390/app9122409

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop