Alginate, Polymer Purified from Seaweed

Abstract

Seaweeds are one of the rich sources of minerals, protein, vitamins, edible fibers, and also have different functional polysaccharides necessary for human nutrition. Alginates are natural polymers that are part of the polysaccharides group. Alginate is a naturally occurring biopolymer that is found in the cell walls of algae or brown seaweed. Sodium alginate is one of the best-known members of the hydrogel group. The hydrogel is a water-swollen and cross-linked polymeric network produced by the simple reaction of one or more monomers. It has a linear (unbranched) structure based on d-mannuronic and l-guluronic acids. The placement of these monomers depending on the source of its production is alternating, sequential, and random. Sodium alginate is the most commonly used form of alginate used in wide range of applications in various industries including the food industry, medicine, tissue engineering, wastewater treatment, the pharmaceutical industry, and fuel. This review discusses its chemical structure along with its production process and application in various industries.

1. Introduction

Seaweeds are one of the renewable resources that are obtained from the marine environment and can be used for treatment and food, and they can be divided into two groups: macroalgae and microalgae. Marine macroalgae are photosynthetic plants that are primary biomasses in intertidal areas [1].

There are about 9000 species of macroalgae, which are broadly classified into three main groups, brown, red, and green algae based on pigments, each of which has a type of polysaccharide, so Alginate is the most abundant in brown seaweed and sometimes makes up more than 40% of the dry weight of brown seaweed. These polysaccharides are obtained from both plant and bacterial sources [2, 3, 4].

The chemical composition depends on the type of species, the age of algae, the number and sequence of G and M units, the growing season, the biological source, and the conditions of algae growth [5, 6].

Seaweeds make up 85% of the total global production of aquatic plants, therefore, they are considered as one of the biggest producers of the sea [7]. Also, they are one of the rich sources of minerals, protein, vitamins, edible fibers, and also have different functional polysaccharides necessary for human nutrition [8]. Alginates are natural polymers that are part of the polysaccharides group, which show unique properties. One of these properties is the ability of alginate to store and transport all kinds of drugs and biological molecules as a suitable substrate and place, which has boosted their use as a biomedical polymer. This polysaccharide extracted from brown seaweed is one of the common gelling agents used in the food industry [9].

Due to the presence of alginate, brown seaweeds are used in many fields such as tissue engineering, microencapsulation of food-drug compounds, and the preparation of special drugs in medical science, and they are of great economic importance [10].

Certain biopolymers like collagen and gelatin are employed in cosmetic surgery, tissue scaffolds, and cellophane for packing materials, and cellulose, hemicelluloses, lignin, starch, and alginate-based biopolymers are employed for 3D printing feedstocks [11].

Biodegradable polymers are usually referred to as “biopolymers” because these polymers are mostly derived from various natural sources. Biopolymers that are naturally biodegradable are limited in number and have the least to minimal effect in increasing the environmental carbon footprint. Biodegradable polymers represent a growing field. A large number of biodegradable polymers (e.g., cellulose, chitin, starch, polyhydroxyalkanoate, polylactide, poly(ε-caprolactone), collagen, and other polypeptides) are made during the growth cycle of organisms in the natural environment. Are or are formed some microorganisms and enzymes capable of degrading such polymers have been identified.

Sodium alginate is a linear polysaccharide derived from alginic acid, which is present in the cell wall of brown algae and contains approximately 30–60% alginic acid. In recent decades, alginates have attracted the attention of researchers due to their unique physical and chemical properties and their wide applications as a natural polymer. Sodium alginate is known with the chemical formula (C6H7NaO6)n and is available in the form of white to brown strands or in granular, powder, and granular form. This salt compound is derived from alginic acid. It is a polysaccharide acid that is widely present in the cell walls of brown algae and forms a sticky gum when hydrated.

Alginates are made up of two uronic acids: D-mannuronic acid (M) and L-guluronic acid (G) extracted from brown seaweeds Phaeophyceae and kelp [12, 13]. The alginic acid form of alginate is extracted from the seaweed in alkaline conditions, then precipitated and ion exchanged (e.g., with potassium). Alginates have a wide application in the cosmeceutical industry because of their use as high-stability thickening and gelling agents. The first alginate application in the cosmeceutical field started in 1927. Alginate is applicable in grafting the skin in plastic surgery [14].

Alginate is the common term for alginic acid salts. Alginic acids are polyuronidic, which is to say polysaccharide molecules that are composed of uronic acid residues. The commercial alginates, such as Laminaria digitata, Laminaria hyperborea, and Macrocystis pyrifera, are currently obtained by removing brown algae. However, several bacteria like Azotobacter vinelandii, a nitrogen-fixing aerobic, and Pseudomonas aeruginosa, an opportunism pathogen, also produce alginates. The alginates are exceptional in their characteristically complex uses for food and pharmaceutical sectors, such as emulators, thickeners, stabilizers, gelling, and film formulation. Biocompatibility, biodegradability, immunogenicity, and non-toxicity of alginate made it an excellent polysaccharide for drug delivery application. Alginate-based bionanocomposites are vital in the biomedical field and are used as instruments in various applications of human health, such as drug delivery excipients (DDS), wound clothing, dental printing materials, and inter alia, formulations for preventing gastric reflux, etc. [15]. This chapter discusses the origin of alginate and its extraction methods and uses.

2. Alginate, polymer purified from seaweed

Alginic acid or sodium and potassium alginates (ALG) are one of the biomaterials of the adhesive mucus, due to its cellular compatibility, biocompatibility, biodegradability, SOL transport properties, and chemical versatility, which allow more GEL-changes to adapt the properties. It makes it possible, it has been studied for drug transfer. This substance is prepared from different types of seaweed. The many advantages of this material have led to the increase of the scientific community’s interest in alginate as a platform for the promotion of new nanomedicine delivery systems in recent decades. The release of water-soluble drugs from the alginate gel matrix is generally done through diffusion, while the drugs with low solubility in water are released through the erosion of the alginate matrix. The potential of different qualities of pharmaceutical side additives has not been fully evaluated, but alginate is likely to make an important contribution to the development of polymeric delivery systems. Natural polymers such as albumin, gelatin, alginate, collagen, chitosan, etc., and other materials can be used alone or in combination with other polymers to formulate nanoparticles. Natural polymers are often cheaper and are often soluble in water, which is effective in protecting drugs and antigens. Biocompatibility and biodegradability are also important features. In addition, chitosan and alginate polymers are mucus adhesive, which is in line with the approach of developing mucosal vaccines. This group of polymers increases the absorption and biosupply of vaccines by increasing the duration of antigen retention in the target tissue or by affecting the tight connections between cells [16, 17].

Alginate is a natural water-soluble polysaccharide extracted from the cell wall of various species of brown algae, i.e., Laminaria, Macrocystis, and Ascophyllum [18]. In fact, alginate is a linear block polymer of 1b-D-mannuronic acid (M) and a-L-guluronic acid (G); the content of M and G units affects its physical properties and determines its industrial utilization. Therefore, alginates with various sources would have specific M-G contents, and consequently, different physical properties [18]. Inherent hydrophilicity of alginate makes it an excellent gel-forming compound, capable of holding large amounts of water.

The word alginate is derived from the word Algae which means algae has been Alginate has been isolated from the cell wall of various types of brown algae such as Macrocystis pyrifera, Laminaria hyperborea, and Ascophyllum nodosum (Figure 1). Alginate is also from some bacteria such as Azotobacter vinelandii can be extracted. Alginates of bacterial origin are rich in structural units. Mannuronic acid has a very weak gel-forming property, and in addition, the production of alginate from bacteria is not cost-effective for commercial use, so alginates from seaweed are often used for mass production [19, 20].

Figure 1.

Origin of alginate: (1) Ascophyllum nodosum, (2) Laminaria hyperborea, and (3) Macrocystis pyrifera.

Alginate is a polysaccharide extracted from the cell wall of phaeophyceae brown algae and is used in the food industry in the form of sodium, potassium, and calcium alginate salts. Sodium alginate is a viscous gum compound and is widely used in the food industry due to its emulsifying, stabilizing, thickening, gel-forming properties in the presence of polyvalent cations, elasticity, and the formation of preservative edible films [21, 22].

Placing the alginate film around the food item preserves the water retention capacity and protects the item against microbial and oxidative spoilage [23]. Unlike chemical preservatives, it is biodegradable and compatible with the environment, it has a protein, polysaccharide (gum, etc.), and lipid origin and does not pose a threat to the health of the consumer [24].

3. Molecular structure of alginate

Alginates are natural anionic polysaccharides belonging to the family of linear copolymers (without branches) found in the cell wall matrix of brown seaweed [25].

Alginate is a general name that refers to a group of natural and non-branched polysaccharide polymers consisting of repeating units of α-L-Gluronic acid and β-D-Mannuronic acid linked by 4 → α1 bonds and having monochain sequences MMMMM and GGGGG together. It is formed by alternating sequences of MGMGMG (Figure 2).

Figure 2.

Structural characteristics of alginate: (A) alginate monomers, (B) chain structure, and (C) distribution of G and M blocks in alginate.

The molecular weight of alginate varies in the range of 92–177 kg/mol along with different G/M ratios. Chain arrays based on the source of extraction and the age of algae have led to the commercialization of more than 277 types of alginate. In addition, the efficiency of drug delivery by alginate depends on the conditions of G/M ratio, molecular weight, concentration, and pH of the environment. One of the most useful features of alginate is its ability to cross-link in aqueous solutions by a mechanism through the carboxylic acid part of the hanging G units with calcium ions and other divalent cations (such as Ba²⁺, Sr²⁺, Zn²⁺) to form a three-dimensional network. This gelation mechanism is explained by the “egg-box” model, in which a divalent cation reacts with 4 COOH- groups (Figure 3), which has been used for more than 3 decades to encapsulate a wide range of drugs, proteins, genes, and cells have been used. Another cation that has been used for cross-linking with alginate is Fe(III).

Figure 3.

A schematic representation of the surrounding of calcium ion in the “egg-box” model for the coupling of gluronate chains in the connection of calcium alginate. The black circles represent the oxygen atoms that are involved in surrounding the calcium ion.

The mechanical and physical stability of alginate gels depends on its G content, the higher the G content, the greater the inflexibility and fragility of the matrix. Also, the process can be reversed in the presence of ion separators such as ethylenediaminetetraacetic acid (EDTA) and sodium citrate. In addition, alginate gels tend to degrade more in neutral and alkaline pH than in acidic conditions. These features encourage its use in chemical stabilization of drugs and oral administration of biological substances that are not stable in digestive tract fluids. From a legal point of view, the US Food and Drug Administration (FDA) has accepted alginate as a GRAS (Generally Referred as Safe) substance, a designation that is used for substances that are accepted for food use by certified professionals is located. In addition, alginate is bioadhesive, mucoadhesive, biocompatible, and hypoallergenic. Therefore, it is used in the production of adhesive molds for the oral delivery of medicine and wound covering with various characteristics, including absorption of secretions, moisture retention, and wound healing, and the production of three-dimensional scaffolds.

Due to its gelling properties, alginate is used in drug encapsulation as a drug delivery tank. In general, there have been many studies that confirm the use of alginate through different prescription ways. On the other hand, the production of alginates with high purity can pave the way for application programs aiming to be more compatible with living systems. Also, in order to improve the properties of alginate, its surface can be modified with other materials.

Due to the hydrophilic nature of alginate, the release of encapsulated drug cargo can follow different mechanisms. In relation to drugs enclosed in alginate polymer, water-soluble drugs are mostly released through diffusion, while drugs with low solubility in water are released through erosion of the alginate matrix. Also, the release of small molecules is faster due to the fact that a cavity with a diameter of about 5 nm is created in the swollen matrix of alginate. However, in order to prolong the release time of the drugs, various changes can be made in the physical and chemical connections of the encapsulated drugs in the polymer network. Also, the interesting feature of alginate is that in dry environments, they are mucus adhesive, which makes the retention and release time longer in various mucous tissues, such as intestines, lungs, nose, and eyes [19, 20].

Alginates are polysaccharides that are the most abundant among marine biopolymers, and after cellulose, they are the most abundant among biopolymers in the world. The process of extracting alginate from brown seaweed is a simple method and it is possible to extract this substance from dried brown algae by using diluted mineral acid and sodium carbonate. The usual use of alginate as an additive in pharmaceutical products generally depends on its gel formation and stability properties. During the gelation process, alginate gel can be prepared with three methods: syringe or dropper, extrusion method, and liquid method. The process of extracting alginate from seaweed is a simple but multi-step method that usually starts with the effect of diluted mineral acid on dried algae. In the next steps, the alginic acid obtained from the previous step is converted into water-soluble sodium salt in the presence of sodium carbonate, and the expected acid or salt can be obtained in the next step. Finally, the obtained sample is purified to be used in different applications (Figure 4).

Figure 4.

Production of sodium alginate isolated from brown algae.

The extraction of alginate can be summarized in five steps (Figure 5). First, the dried and crushed brown seaweeds were extracted with a mineral acid (e.g., HCl, 0.1 M), leading to insoluble alginic acids which are easily separated from other contaminating glycans such as sulfated fucoidans and laminarans by filtration or centrifugation. The insoluble residue is then treated by alkaline solution (using sodium carbonate, sodium hydroxide, or aluminum hydroxide, above pH = 6.0) to convert insoluble alginic acid into sodium alginate. After another separation step, the soluble sodium alginate is precipitated using calcium chloride or cold alcohol. Alginates are then purified using techniques such as acidification, the addition of Ca +2 ions (calcium alginate formation), or the addition of ethanol (dielectric stabilizer) [26].

Figure 5.

Production process and applications of alginates.

4. Preparation of alginate gel-forming beads

Beads can be prepared by gelation method. This method, it has undergone changes that are mentioned below:

1. Syringe or dropper method.

2. Extrusion method.

3. Laminar jet break-up or prilling method.

4.1 Syringe or dropper method

This method includes the formation of hydrogel beads by alginate solution with a solution containing multivalent ions (mainly with two positive charges). Multivalent ions help the formation of willows by forming a bond with alginate. This is the most common method used and can be modified in many ways to provide the desired shape, size, and therapeutic effects. Sodium alginate solution is prepared in different concentrations. The drug (if it needs a suitable carrier) is added to this solution, the said mixture is stirred and enough time is provided for it to stabilize. This mixture is then added drop by drop to the solution containing divalent ions (different concentration) in different pH conditions. As a result, the formed willows are washed with different mixtures and dried under different conditions. Wet willows can be coated with polymers such as chitosan and then dried to change the release. Sodium alginate solution is mixed with drug solution and polymer, such as chitosan is added to this mixture. Then the resulting mixture is gelled with a solution containing divalent ions in the above form. More changes can be applied by adding alginate solution to the mixture of divalent ion salt and polymer (chitosan). Then the formed willows can be gelled through similar processes.

4.2 Extrusion method

Extrusion is the process of making something with specific dimensions by pushing or pulling material through a die with a desired cross-section. The sodium alginate solution is mixed with the drug solution and transferred drop by drop into the two-volume metal salt solution by extrusion through a silica tube using a peristaltic pump. This method can be used for all the above-mentioned samples of medicine, alginate solution, and multi-capacitance electrolyte solution of gels. The resulting willows are filtered and dried at the optimum temperature.

4.3 Laminar jet break-up or prilling method

This method is a process of preparing small droplets through an upward airflow when in contact with a sodium alginate solution at a constant temperature and moving downward. To make willows, a vibrating nozzle tool is pumped into the solution of divalent metal salts at different speeds through the nozzle of solution drops. Finally, the formed willows are filtered and dried at the optimum temperature. This method has been widely used to produce microparticles with a very small dimensional range and high-encapsulation efficiency, especially in biotechnology for cell stabilization.

As a result, it can be said that according to different needs in the drug delivery industry, alginate polymer, which is purified from brown algae, can be widely used in modern drug delivery due to its various advantages, including biocompatibility [27, 28].

5. Modification of alginate by processing methods

As the properties of polysaccharides are tightly related to their structures, the modification of alginate sometimes affects its properties. The molecular weight reduction of the alginate occurs through a uronic acids release by proton-catalyzed hydrolysis in acid conditions (pH < 5), and elimination reaction in neutral and alkaline conditions (pH > 5) [29, 30]. Microwave-assisted acidic hydrolysis of alginate has the same effect as normal acid hydrolysis, but it accelerates the reaction [31]. Ultrasound treatments of alginate at different frequencies cause polymer structure degradation, rearrangement, and alteration of its molecular weight, reducing the M/G ratio (changing hydrophobic interactions). As a result, they are harder than untreated polymers [32, 33]. High-power electrical energy (several tens of kilojoules) is used in the high-voltage electrical discharge method. If the electric field is strong enough, an electron avalanche will be the starting point for the spread of the streamer from the high-voltage needle electrode to the plate electrode. High-pressure shock waves, bubble cavitation, and fluid turbulence are produced and lead to partial decomposition and damage to the cell wall, which accelerates the extraction of biomolecules from biomass. Studies have shown that the molecular weight of alginate extracted by applying the high-voltage method was similar to that extracted with the classical method but had a higher polydispersity. Alginate fragmentations and degradations occurred leading to heterogeneity in M_w distribution. This method had logically no effect on the sequence ratio of this biopolymer [34]. Molar mass, polydispersity, and the intrinsic viscosity of alginate fall simultaneously during ultra-high-pressure homogenization (HPH) without any change in its conformational structure [35].

6. Applications of alginate

Alginate is extracted from seaweed composed of a linear copolymer of D-mannuronic and L-guluronic acid monomers. These films are demonstrated to be effective against L. monocytogenes, E. coli, and Salmonella typhimurium [36]. Alginate is widely used in many fields such as cell immobilization, tissue engineering, microencapsulation of detergents and pharmaceuticals, as well as coating and edible film for food products [29, 37].

6.1 Food applications

Natural biopolymers as nanocarriers, such as cereals, alginate, starch, casein, whey protein, gelatin, zein, gluten, chitosan, and so on, have revolutionized the food industry as they have been successfully incorporated for encapsulating daily food by using nano- or microtechnology to ensure healthy, safe, sustainable, secure, and good-quality food [38].

Sodium alginate is a water-soluble polymer that creates highly viscous solutions and can be used as a stabilizer, stabilizer and thickener in various industries, especially food industries [39].

Alginate is commonly used in the food industry to modify some food characteristics such as rheology (thickening), water binding capacity, stabilizing emulsion, and film formation [40]. Combined active compound and alginate coating or thin-layered structures are used to increase the storage period of tomato (Solanum lycopersicum L.) [41], mushrooms (Agaricus bisporus) [42], shrimp [43], turkey filet [44], chicken thigh meat [45], low fat cut cheese [46], and meat [47]. Because of thickening and gelling properties, it can be used in sauces, jam, marmalade, syrups, ice cream toppings, and in fruit pies, and animal food. In the production process of ice cream, the use of propylene glycol alginate in low concentrations results in a soft tissue, low ice crystals and gives desirable feeling to customers during production to consumption. Another alginate application is stabilizing fruit drinks and beer. Alginate is useful in mayonnaise and salad dressing which we know of as water-in-oil emulsions [48]. Calcium alginate structures are considered by the meat industry as an alternative to natural casings from animals. In a 2015 study on the replacement of alginate structures with natural coatings in fermented sausages, at 12 _C, it was found that alginate coatings could be a suitable alternative to natural coatings [49]. The physiological and rheological properties of alginates, as well as their applications as stabilizers, thickeners, gels, or pharmaceutical additives, are strongly influenced by the composition of uronic acids (M/G ratio) and the distribution of monomers along the chains [50]. Alginate is used due to its low-water solubility and high viscosity, especially in food products. This polysaccharide has antioxidant properties and prevents the unpleasant role of free radicals and oxidative damage in foods and improves the quality of nutrition. Its structural properties such as molecular weight, monosaccharide composition, and glycosidic branching affect its antioxidant activity. The molecular weight and M/G ratio of alginates play an important role in their ability to inhibit free radicals. Low-molecular weight polysaccharides were hypothesized to have more reducing hydroxyl groups (by mass) to accept and scavenge free radicals. On the other hand, the higher proportion of G monomers increases the antioxidant activity because the diaxial bonding in these blocks may cause a hindered rotation around the glycosidic bond. As a result, the flexibility of G-blocks increases, thereby affecting the availability of hydroxyl groups in sodium alginate and the ability to donate H-atoms. Alginates also have the ability to inhibit lipid peroxidation of phosphatidylcholine and linoleate liposomes, protect NT2 neurons from H2O2-induced neurotoxicity, and inhibit free radical chain reactions [51]. A study on sodium alginate from the Tunisian seaweed Gongolaria barbata (formly Cystoseira barbata) in 2015 found that it was composed of 37% manuronic and 63% guluronic acids. It is less sensitive to temperature changes and is more stable at an acidic pH. The compound has also been studied for its antioxidant properties and has moderate antioxidant activity and strong protective activity against DNA breakage. Therefore, this alginate could be used as a natural substance in the food or pharmaceutical industries [52]. Alginate is very useful to encapsulate some strains of live cell of probiotics in both intestinal tract and food products [53]. The microencapsulation technique protects live bacteria during storage time [54]. Generally, alginate can be used as an additive (thickener, emulsifier, stabilizer, etc.) at very low concentrations in milk chocolate and as an ingredient in functional foods (probiotics and prebiotics) [53].

6.2 Non-food applications

Alginate is another biopolymer that has been used for wastewater treatment [55]. Calcium alginate was modified using graphene oxide and reduced with PEI to improve its adsorption performance for Pb (II), Hg (II), and Cd (II) from aqueous solutions. The study showed that functionalized graphene oxide calcium alginate had a better adsorption capacity as compared to the non-functionalized adsorbent beads. Maximum adsorption capacities of 602, 374, and 181 mg/g were observed for Pb (II), Hg (II), and Cd (II), respectively [56].

6.3 Pharmaceutical applications

Alginates are made up of two uronic acids: D-mannuronic acid (M) and L-guluronic acid (G) extracted from brown seaweeds Phaeophyceae and kelp [12, 13]. The alginic acid form of alginate is extracted from the seaweed in alkaline conditions, then precipitated and ion exchanged (e.g., with potassium). Alginates have a wide application in the cosmeceutical industry because of their use as high-stability thickening and gelling agents. The first alginate application in the cosmeceutical field started in 1927. Alginate is applicable in grafting the skin in plastic surgery. In wound dressings, hydrogels from gelatin, chitosan, pectin, and alginate are used in the creation of a moist environment in wounds. Calcium alginate, chitosan, collagen, and gelatin are a few examples of biopolymers used in the pharmaceutical industry for purposes such as controlled drug release, artificial skin, dental materials, and cosmetics, among others [55]. Alginate is a widely explored seaweed anionic polysaccharide offering numerous benefits such as non-toxicity, biocompatibility, biodegradability, non-antigenicity, and ease of gelation. It is employed in 3D bioprinting for a variety of biomedical and pharmaceutical applications, such as wound healing, cartilage repair, bone regeneration, and drug delivery [55].

The quality of the alginate mostly depends on the species and the climatic changes. The anionic biopolymer has the key property to form gels in the presence of cations. Sodium alginate is the most commonly used form of alginate used in biomedical and industrial applications [57]. Alginates can be molded to scaffolds, hydrogels, and composites for use in pharmaceutical applications. Some of the pharmaceutical applications of the alginates include drug delivery, protein delivery, wound dressings, and cell culture [58, 59]. Different forms of alginates are also used in blood vessel tissue regeneration, bone tissue engineering, cartilage tissue engineering, muscle, nerve, pancreas, and liver tissue engineering applications [60, 61].

In wound dressings, hydrogels from gelatin, chitosan, pectin, and alginate are used in the creation of a moist environment in wounds. Calcium alginate, chitosan, collagen, and gelatin are a few examples of biopolymers used in the pharmaceutical industry for purposes such as controlled drug release, artificial skin, dental materials, and cosmetics, among others. On the basis of the aforementioned pharmaceutical products, the global biopolymers market is expected to dominate the synthetic polymers market. Promisingly, according to Energias Market Research, the worldwide medical bio-based polymers market is predicted to witness a compound annual growth rate (CAGR) of 15.2% during 2018e24 [62].

7. Conclusion

Biopolymers such as proteins and polysaccharides can be extracted directly from plant or animal biomass. Extensive research is being done on polysaccharides like cellulose, starch, alginate, carrageenan, PLA, PCL to derive desirable biopolymers [63]. According to the research results of a study conducted in 2019 [64]. The results of chemical analysis showed that, in general, Alginate and salt coating slows down the increasing process of indices. Oxidative damage was observed compared to the treatment. The presence of preservatives such as salt and alginate prevents the activity of organisms which itself causes the reduction of protein denaturation and as a result Reduction of water loss and less change of tissue characteristics in some of the studied treatments.

Also alginate with properties Antioxidation delays chemical spoilage It prevents tissue problems [65, 66, 67]. Alginate has the ability to form a gel, emulsify, stabilize, and have antioxidant properties, and it prevents the product’s fatty acid changes during the storage period [68, 69]. Tugce Senturk Parreidt et al. [47] used alginates, which are naturally occurring polysaccharides in the bio-industry. They are mainly derived from brown algae species. Alginate-based edible coatings and films attract interest for improving/maintaining quality and extending the shelf-life of fruit, vegetable, meat, poultry, seafood, and cheese by reducing dehydration (as sacrificial moisture agent), controlling respiration, enhancing product appearance, improving mechanical properties, etc. The most recent essential information concerns alginate-based edible coatings. The categorization of alginate-based coatings/film in food packaging concept is formed gradually with the explanation of the most important titles. Emphasis will be placed on active ingredients incorporated into alginate-based formulations, edible coating/film application methods, research and development studies of coated food products, and mass transfer and barrier characteristics of the alginate-based coatings/films. Future trends are also reviewed to identify research gaps and recommend new research areas.