This kind of combination of natural and synthetic polymers has long been worked on to utilize the mechanical properties of PCL while preserving alginate hydrophilicity to support cell adhesion.
The composite displayed that a good suture pulled out strength and assists the human mesenchymal stem cells hMSCs viability, adhesion, proliferation, and neurogenic differentiation in neural induction media. Drug delivery area involves an art of transporting drugs or therapeutic compounds to human body.
It is a critical research field where the transported compounds must achieve the optimum therapeutic effect to protect or heal from any kind of disease. Therefore, controlled delivery systems were proposed by addition of various fillers into polysaccharide matrix.
This includes incorporation of Fe 3 O 4 [ 53 ], CaCO 3 [ 54 ], silica nanoparticle [ 55 ], graphene oxide [ 56 ], gold nanoparticle [ 57 ], and montmorillonite [ 58 ]. However, drugs taken through oral route have to pass through different phases of gastrointestinal tract, where pH values vary greatly.
The change in pH may lead to loss of mechanical strength and fast degradation. Protein drugs were encapsulated in inorganic carrier [ 59 , 60 ] and gel beads [ 61 , 62 ] to prolong their release. Polysaccharides like starch and carrageenan are thermoresponsive polymers.
They can be utilized in drug delivery with thermal sensitivity. The effect of both nanoparticles on the microstructure and strength of the hydrogel had implications in the mechanism of controlled release as demonstrated by in vitro release studies using a drug model and displayed potential for thermally controlled drug delivery.
Schmitt et al. The swelling of the produced nanocomposite strongly depends on the temperature but not on pH. The swelling capacity and drug release of? Another interesting functional hydrogel of? Apart from being too focused on the additional function on drug carrier material, excipients must have the ability to encapsulate and protect the drugs. Some drugs have some specific needs to achieve targeted release.
Targeted release is very important to ensure optimum drug effects. Aceclofenac is an orally administered phenyl acetic acid derivative with effects on a variety of inflammatory mediators. Its frequent administration and prolong treatment was associated with various side effects. Highly hydrophobic drug like curcumin frequently has poor solubility in polysaccharide excipients. The composite was then coated with poly? Recently, the potential application of deferoxamine DFO in several iron dysregulation diseases has been highlighted.
The disability of conventional plastic material used in packaging to biodegrade has led to serious solid waste problem. Packaging basically functions as container and external preserver or protector to consumer goods including food. Therefore, several reinforcements have been identified to be good fillers for polysaccharide films. Nanoclays have been a subject of interest nowadays considering their high aspect ratio and surface area, alongside with biocompatibility feature.
The inclusion of clays showed good dispersion in polysaccharide matrix and resulted in superior mechanical and barrier properties. MMT may also enhance the thermal stability, storage modulus, and barrier properties of chitosan [ 78 ]. Cellulose nanocomposite foam containing MMT was investigated as a substitution for synthetic polymer foam trays.
The presence of nanoclay caused more uniformity in the structure of the foam, thus resulted in higher compressive strength, Young's modulus, and density [ 80 ]. The use of sepiolite and palygorskite fibrous clays in some polysaccharides of different types was reported [ 81 ]. The good compatibility between these fibrous clays with the polymers resulted in improved mechanical properties, barrier to UV light, stability in water, and reduction of water absorption, which make them very attractive bionanocomposite in the food packaging sector.
In terms of polysaccharide composites, certain fillers were added to the packaging films not only to improve their mechanical and barrier properties, but special characteristics can also be instilled for the production of active packaging films.
Introduction of different kinds of natural and synthetic antimicrobial agents into packaging have been studied against various pathogens such as Listeria monocytogenes , Escherichia coli , Clostridium perfringens , Staphylococcus aureus , Salmonella pullorum , Bacillus cereus , and Pseudomonas aeruginosa. The inhibitory effect of the films was determined by measuring the bacterial growth inhibition zones.
Clays are organically modified to increase their hydrophobicity since the polysaccharide matrix is already water sensitive and has low water vapor barrier properties. They also exhibit biocompatibility, bioactivity, and can be used as antibacterial materials. A combination of halloysite nanotube and nisin had been expected synergistic effect in active packaging [ 87 ]. Nisin is an antimicrobial agent recognized to fight against Listeria and spores of Bacilli and Clostridia.
However, a study by Lu et al. Lower concentration of alginate was proposed to see the effect of alginate concentration to nisin performance. Another study included silver Ag nanoparticles combined with Cloisite 30B in? Ag nanoparticles have attracted considerable attention for packaging application for their antibacterial activities, high thermal stability, and low toxicity. Thus, the combination of these two antibacterial agents helps in providing polymer packaging with strong antimicrobial properties.
Shankar et al. Strong antimicrobial activities can also be induced inside packaging films by plant extracts and essential oils. Extracts of green and black tea were added into chitosan displayed good antioxidant and antimicrobial capacity [ 91 ]. Natural extract from the seeds, pulps, and peel of grapefruit was also put inside carrageenan film to encourage the antibacterial, antifungal, and antioxidant properties [ 92 ].
However, addition of plant extracts showed decreased tensile strength and elongation at break of the packaging films. The tensile strength was lowered with increasing essential oil concentration. They are easily processable and abundant in nature, forming a vast potential economical application compared to other synthetic biomaterials. Moreover, they are highly environmental friendly and nontoxic to humans and animals.
Substances such as cellulose, which is a majority component of wood, are composed through linked polysaccharides. Pectins, another type of structural polysaccharides, are found throughout plant parts and primary cell walls. These polysaccharides can easily get tangled among themselves, causing the substance to substantially thicken.
Chitin, another natural polymer, is degradable and easily broken down via various enzymes secreted by organisms like bacteria. Obviously, the production of non-natural plastic is a rather large industry among humans. Its synthesis forms large-massed molecules often entwined with other components so as to increase performance and durability. Petroleum and natural gas form the catalysts that enable commercial plastic production.
How are plastics different from polysaccharides? What is the difference between polysaccharides and plastics?
How are plastics similar to polysaccharides and how are they different? What is the similarity between plastics and polysaccharides? How are polysaccharides and protein similar? What ways are protein molecules similar to polysaccharides? How is plastic and polysaccharides similar?
How are the polymers cellulose and chitin similar? What plastics does epoxy glue? Plasticsis synthetic organic polymers how are plastics similar to polysacchical how are they different? What are polysaccharides known as? Do grains contain polysaccharides? What is the function of Polysaccharides? Is polysaccharides a portein? What is acidic polysaccharides?
What is the difference between an elastomer and plastics? What are compounds with more than two simple sugars joined together? What compounds with more than two simple sugars joined together? What are the subunits of polysaccharides? Are polysaccharides types of proteins? What are monomers of polysaccharides? What are monomers of polysaccharides are? The functional properties of chitosan-based membranes may also be improved by combination with other hydrocolloids.
Blends of chitosan and anionic polymers have been reported to have improved mechanical and barrier properties when compared to those made of chitosan only.
This fact is attributed to the formation of polyelectrolyte complexes through electrostatic interactions between the protonated amino groups of chitosan and the negatively charged side-chain groups in the other biopolymer at the operating pH [ 26 , 29 ].
Improvements in mechanical properties, better performance in terms of water vapor permeability and lower water solubility have been reported for combinations of chitosan with other polysaccharides, such as starch, pectin or alginate [ 29 , 30 , 31 ] and proteins, like gelatin [ 32 ] and whey proteins [ 33 ], compared to chitosan membranes.
A wide range of lipid components is available, such as natural waxes, resins, fatty acids and vegetables oils [ 34 ]. A decrease in water susceptibility has been reported for chitosan-based membranes with beeswax [ 35 ], and decrease in water vapor permeability was described for chitosan-based membranes with oleic acid [ 36 ], neem-oil [ 37 ], cinnamon essential oil [ 38 ], among others.
The manufacturers and suppliers of chitosan and chitin products are present worldwide. Starch is the most abundant reserve polysaccharide in plants. As such, it is a renewable resource, biodegradable, produced in abundance at low cost, easy-to-handle and can exhibit thermoplastic behavior. Starch can be extracted from cereals e. This polysaccharide has the ability to form membranes and coatings with very low oxygen permeability, however its applicability as packaging material is dependent on its high hydrophilic character, limited mechanical properties and the retrogradation increase in crystallinity over time, leading to increased brittleness [ 42 , 43 ].
Research has been carried out to overcome these drawbacks, mainly using plasticizers, which increase the chain mobility and improve the flexibility, to create starch plastics with mechanical properties comparable to polyolefin-derived ones. The most used plasticizers are polyols such as glycerol, glycol and sorbitol [ 44 , 45 , 46 , 47 ]. Other studied approaches consist on designing blends and composites, as well as starch chemical modification to produce a biodegradable material with appropriate mechanical strength, flexibility and water barrier properties for use as packaging material.
Blending starch with more hydrophobic polymers is widely studied e. In addition, Eco-Go Bangkok, Thailand sells finished packaging products e. Galactomannans are neutral polysaccharides obtained from the endosperm of dicotyledonous seeds of several plants, particularly the Leguminosae , where they function as carbohydrate reserves [ 54 ]. However, just locust bean gum and guar gum are considered commercially interesting due their availability and price [ 56 ].
These natural polysaccharides are commonly used in the food industry, mainly as stabilizers, thickeners and emulsion stabilizers, as well as for the production of edible membranes and coatings.
The galactomannans ability to form very viscous solutions at relatively low concentration and their resistance to pH alterations, ionic strength and heat processing are their main distinct characteristics.
The mechanical and barrier properties of galactomannan membranes and coatings are the basis of their application to improve the shelf-life, safety and quality of food products [ 14 , 54 ]. Edible membranes and coatings of galactomannans have been applied for example in fruit and cheese.
They have been tested in apples to decrease the internal oxygen concentration. Sensory analyses revealed that the coated apples maintained consistent quality in firmness, crispness and juiciness [ 58 ].
Coatings based on galactomannan, glycerol and corn oil have been applied in cheese, decreasing the transfer rates water vapor and oxygen , weight loss and color change [ 59 ]. Chemtotal Chatswood, Australia also produces and trades galactomannans guar gum, locust bean gum, tara gum and cassia gum. Other companies producing and commercializing galactomannans include Altrafine Gums Ahmedabad, India , with exportation to 90 countries of a wide range of different gums. Cellulose is the most abundant occurring natural polymer on earth, being the predominant constituent in cell walls of all plants.
Due to its regular structure and array of hydroxyl groups, it tends to form strong hydrogen bonded crystalline microfibrils and fibers and is most familiar in the form of paper, paperboard and corrugated paperboard in the packaging context [ 17 , 22 ].
Its great interest is related with specific properties such as low density, high mechanical strength, low cost, durability, non-toxicity, renewability, biocompatibility, biodegradability, good films-forming performance, chemical stability and ease of making chemical derivatives [ 60 , 61 ].
The most used raw material source for production of cellulose based products are wood and cotton fibers and in small amounts stalks of sugarcane bagasse. Natural cellulose fibers are low cost, biodegradable and have good mechanical properties, but they are difficult to use for industrial applications due to their hydrophilic nature, insolubility in water and crystallinity [ 17 , 19 ]. Cellulosic materials are usually used in textiles, fibers and packaging and can be divided into two groups: regenerated and modified cellulose.
Chemical reactions are usually performed to improve the thermoplastic behavior of cellulose, such as etherification and esterification that are conducted on the free hydroxyl groups.
Numerous derivatives are commercialized, but the main ones used for industrial purpose are cellulose acetate, cellulose esters for extrusion and molding, and, in structures, as membranes and regenerated cellulose for fibers.
To overcome the hard mechanical properties of cellulose, beyond chemical modification, the use of plasticizers and blends with other polymers are also used, being the final mechanical and chemical properties dependent on the blend composition. To produce cellophane membranes, for example, cellulose has to be dissolved in aggressive and toxic solutions, and then recast in sulfuric acid. In that way, it is possible to produce a hydrophilic layer with good mechanical properties.
However, this structure does not have thermoplastic properties and cannot be heat-sealed [ 17 ]. Nowadays, a large number of companies are suppliers of cellulose membranes.
Weifang Henglian Films CO. LTD Weifang, China provides food grade cellulose films with different sizes adapted for specific products. Carrageenan is a naturally occurring hydrophilic, anionic sulfated linear polysaccharide extracted from red seaweeds, specifically from the Rhodophyceae family e. Carrageenan is approved as food-grade additive, and it has been used mainly as emulsifier and stabilizer in flavored milks, dairy products, pet food, dietetic formulas and infant formulas [ 65 , 67 ].
Carrageenan is also used to produce edible films and coatings, though the reports about its application in coatings are much more common. Carrageenan edible films and coatings and their blends with other polymers were reported to be used in food to preserve fresh cut fruits, by reducing moisture loss and decreasing gas exchange, as well as preventing the discoloration and maintaining texture [ 68 , 69 ].
Membranes of carrageenan have also been reported as encapsulating matrices of aroma compounds [ 64 , 70 , 71 ]. JetNet Corporation Sewickley, PA, USA produces carrageenan membranes, in particular Nutrafilm TM carrageenan film packaging for meat and poultry, and over different styles and sizes of elastic netting [ 73 ].
Alginate is a linear polysaccharide that is abundant in nature and is synthesized by brown seaweeds e. Laminaria digitata and Ascophyllum nodosum and some soil bacteria. The physical properties of alginates depend on the relative proportion of these three blocks, which are directly related with extraction source [ 74 ].
They are appealing film-forming compounds because of their non-toxicity, biodegradability, biocompatibility and low cost. In addition, other functional properties have been studied, such as thickening, stabilizing, suspending, gel-producing, among others [ 22 , 64 , 75 ]. Sodium alginate is the most used in industry and was the first by-product from algal purification. Having an efficient brown seaweed extraction would be interesting for producing an environmentally friendly biopolymer-rich extract for industrial applications, such as food packaging material, release agents, paper, pharmaceutical and medical uses, among others [ 64 ].
Due to the linear structure of alginate, the membranes are strong, with adequate fibrous structures in solid state, being considered a good filmogenic material [ 76 ]. The properties and applications in food packaging of the polysaccharides obtained from animals, plants and algae are summarized in Table 1.
Properties and food applications of polysaccharide membranes obtained from animals, plants and algae. Several polysaccharides with film-forming ability can be produced by microorganisms yeast, fungus or bacteria , such as pullulan, gellan gum, xanthan gum, FucoPol, bacterial cellulose or bacterial alginates.
This section will focus on the most used polymers except bacterial cellulose and alginate referred before. The molecular weight of pullulan, ranging from 4.
The commercial production of pullulan began in by the Hayashibara Company Okayama, Japan. Its production was an outgrowth of starch syrup production, noted in Pullulan membranes started to be commercialized by Hayashibara in [ 82 , 83 ].
Pullulan is biodegradable, non-toxic, tasteless and odorless. It can be used as food additive, as flocculent agent or even as blood plasma substitute, beyond film forming agent. Pullulan membranes are edible, homogeneous, transparent, printable, heat sealable, flexible and good barriers to oxygen [ 20 , 84 , 85 ]. However, they are water sensitive and mechanically weak [ 86 , 87 ].
These properties, and the fact of pullulan membranes inhibit fungal growth, make them a good material for food applications. Despite all advantages of pullulan, its high cost has limited the use of pullulan and pullulan membranes in several applications.
Research has been carried out on blending pullulan with other biopolymers and additives to produce membranes with better physicochemical characteristics and mechanical properties. Blends of pullulan with alginate, chitosan, cellulose, and starch have been reported with improvements in thermal and mechanical properties, low water vapor permeability and low water absorption [ 88 , 89 , 90 , 91 , 92 ].
Composite membranes of pullulan with lipids and proteins have also shown improved properties. Pullulan membranes with gelatin have demonstrated higher tensile strength and reduced oxygen permeability and cost [ 93 ], while the use of rice wax has shown improvements in water vapor barrier properties [ 86 ]. Zhucheng, China is also a key producer of pullulan Jinmei Pullulan , which is commercialized in powder or capsules forms, with application in edible and oral dissolving membranes, coatings in soft candies, among others [ 94 ].
Gellan gum is an anionic water-soluble exopolysaccharide, produced by Sphingomonas elodea , also known as Auromonas elodea or Pseudomonas elodea. Gellan gum was identified as a product with potential commercial value by Kelco Atlanta, Georgia, USA during an extensive screening program of soil and water bacteria.
In its original form high acyl gellan , gellan gum has two acyl substituents acetate and glycerate. Low acyl gellan gum is obtained with removal of acyl groups [ 95 , 97 ]. High acyl gellan forms soft, elastic, non-brittle, thermo-reversible gels, and low acyl gellan tends to form firm, non-elastic brittle and thermostable gels [ 97 , 98 ]. In food industry, gellan gum is usually used as additive stabilizer, thickening agent and gelling agent , however the applications of gellan gum may also be extended to membranes and coatings for food industry, such as breading and batters for chicken, fish, cheese, vegetables and potatoes, coatings and adhesion systems.
These membranes and coatings offer advantages, essentially due to their ability to reduce oil absorption by providing an effective barrier. In batters, for example, product crispness is maintained long after frying or baking, which helps to maintain product quality under heating lamps [ 99 ].
Dancheng Caixin Sugar Industry co. Ltd Zhoukou, China is also a producer and worldwide seller of high and low acyl gellan. Xanthan gum is an exopolysaccharide produced by Xanthomonas campestris using glucose and sucrose as sole carbon source.
Nowadays, it is the most extensively studied and widely accepted industrial microbial biopolymer, being the most significant bacterial EPS in global hydrocolloids market [ , ]. This heteropolysaccharide consists of repeated pentasaccharide units composed og glucose, mannose and glucuronic acid ratio and pyruvate and acetyl substituent groups [ ]. Xanthan is water-soluble and non-toxic. It imparts a high viscosity at low concentrations in aqueous media, with a strong shear-thinning behavior.
The rheological properties of xanthan solutions are quite stable in a wide range of pH, ionic strength and temperature values [ , ]. Xanthan gum has been used in a wide variety of industrial applications, such as food, cosmetic, pharmaceutical, textile, petroleum production or even slurry explosives. In food industry, it is mainly used as additive suspending and thickening agent [ , ]. Thus far, there is not much information about xanthan membranes for food packaging, maybe caused by the current high cost of xanthan production [ ].
Nevertheless, xanthan coatings applied to acerola, showed it is an effective system for reducing the weight loss and the respiration process, keeping the color and eventually increasing the shelf-life [ ]. FucoPol production at lab-scale has shown productivities and yields comparable to other commercial microbial bacterial polysaccharides, such as xanthan and gellan [ ]. Although this polysaccharide is not commercially available yet, the scale up of its production is being developed.
FucoPol has demonstrated flocculating and emulsion stabilizing capacity, comparable to commercial polymers [ ]. FucoPol has also shown to have a good thickening capacity in various aqueous formulations with a wide range of pH and ionic strength [ ].
These functional properties make this polymer a good alternative in several applications in the food, pharmaceutical, cosmetic, textile, paper and petroleum industries.
FucoPol has also shown membrane-forming capacity. Its membranes have been reported to be transparent, with brownish tone, ductile behavior, water soluble, with low water vapor barrier properties but high barrier properties to gases in particular CO 2 and O 2.
Taking ito account these properties, FucoPol based membranes have good potential to be incorporated as an inner layer in a multilayer packaging material [ ]. Moreover, FucoPol and chitosan bilayer membranes have shown enhanced properties when compared to FucoPol stand-alone membranes. They exhibited better gas barrier properties, lower solubility in liquid water, and better mechanical properties.
The properties and applications in food packaging of the microbial polysaccharides are summarized in Table 2. In this work, the state of the art on polysaccharide-based membranes use for food packaging applications was revised. Polysaccharides extracted from different origins animals, plants, and algae and produced by microorganisms have been described. Intensive academic and industry research is being carried out to find new and improved polymers, production methods, sources and properties, to obtain biopolymers in particular, polysaccharides that may replace the conventional synthetic and non-biodegradable ones as packaging materials.
The future trends are related with industrial development, able to produce competitive products in performance and price. A detailed life cycle analysis, taking into account all aspects from production costs still higher for biopolymers to direct and indirect waste disposal threat costs, is essential to evaluate the economic value of polysaccharide membranes in comparison to their non-biodegradable counterparts.
The improvement of existing polysaccharide membranes, particularly regarding their mechanical properties, resistance to liquid water and permeability to water vapor, is mandatory. The strategies may include the use of additives such as lipids , blends with different polymers, design of multilayered membranes, use of nanoparticles, and polysaccharides chemical modification. This ambitious challenge is crucial for a more sustainable approach in the production of packaging for food products.
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