Starch is one of the main constituents of human diet, belonging to the general category of biomolecules called polysaccharides, and it is contained in foods such as potato, rice, maize, corn, and wheat [35,36,37]. Starch consists of two biopolymers, namely the linear amylose and the amorphous amylopectin. The chemical structure of amylose consists of molecules of a-D-glucose connected with a-(1-4) glycoside bond, while amylopectin has the same chemical structure with the presence of branches.

Starch is used in food packaging as both film packaging and coating. As film packaging, starch presents advantages such as excellent barrier properties in gases, high biodegradability, biocompatibility, availability, and edibility as well as low cost, abundance, harmlessness, and its ability to be modulated easily to films due to the presence of hydroxyl groups [38]. On account of these properties, starch is considered a good choice for food packaging. Its high barrier properties to gases permit the use of starch in the packaging of fruits and vegetables with high respiratory activity and that are sensitive to oxidation [39,40]. Strawberries coated with starch from corn solution retained their firmness, clarity, and color and had a lower weight loss. Moreover, the addition of essential oils to starch coatings better controlled the growth of pathogens and increased the shelf life of strawberries and vegetables [41].

Despite these advantages, the use of starch in food packaging has also some disadvantages, such as its brittleness and its susceptibility to water. These drawbacks can be solved by the addition of plasticizers such as glycerol and polyglycerol [42,43] and various additives such as cellulose, gelatin, chitosan, and citric acid [38]. The properties of starch can de also improved by using a deep eutectic solvent and formulation under reactive extrusion conditions (high pressure and temperature and low moisture content) [44]. Blending starch with many synthetic biodegradable polymers such as polylactic acid (PLA), polyvinyl alcohol (PVA), polycaprolactone (PCL), polybutyl succinic acid-butyl adipate (PBSA), and polyadipate butylene terephthalate (PBAT) improves the mechanical properties, the processability, the biodegradability, and the poor resistance to moisture of starch-based biodegradable packaging materials [45,46].

Starch-based films can be used in monolayer or laminated forms with other films as a result of the upgradation of barrier properties. Furthermore, when these films are combined with flexible polyesters (PBAT), they become more flexible, while blending with PLA upgrades their rigidity and thermoforming properties [47]. Moreover, the use of nanomolecules such as nanoclay or zinc in starch-based films upgrades their mechanical properties [48,49,50,51]. Moreover, the starch-based films have the advantage of shape memory [41]. The materials with shape-memory characteristics can transform from the temporary phase to permanent phase when exposed to specific conditions of temperature, humidity, pH, etc.

The antimicrobial effect of various incorporated antimicrobial factors on starch-based films has been investigated by several authors. Bakery products packaged with Manioka starch-based films presented higher resistance to fungi attack and higher shelf life after the addition of essential oils into the films [49,52]. The incorporation of citric pectin and flour from Feijoa peel into starch-based films was used in apple packaging [53]. Furthermore, maqui berry extract incorporated into cowpea starch-based films was used for salmon packaging [54]. Another study reported that yam-starch-based films fortified with eugenol were used in pork packaging [55]. In addition, a bilayer film consisted of PLA and pea starch was used for cherry tomato packaging [56]. Similarly, rey-starch-based films containing rosehip extract were used for chicken breast packaging [57] and a mixture of acetylated cassava starch and green tea with linear low-density polyethylene films for sliced bacon packaging [58]. From these references, it is evidenced that starch-based films are the most appropriate packaging films for the substitution of conventional film packaging materials.

Cellulose is a biopolymer that is a part of the polysaccharides group. It is crystalline, strong, and resistant to hydrolysis. Chemically, cellulose consists of plenty of β-D-glucose molecules linked together with β-(1-4) glycoside bonds. Cellulose is the most abundant component of plants [59], and it is found in the cellular walls of plants, peels of fruits and vegetables, wood, agricultural residues, factory and food waste, food leftovers, cereal brans and husks, sugarcane bagasse, corn kernels, and many forms of algae along with different types of grass and even oomycetes [60,61].

The use of cellulose in food packaging exhibits many advantages that can be recognized as follows: (i) high mechanical and physical properties and (ii) high thermal resistance. However, its use has some limitations, such as its high water absorbability and the insufficient interfacial adhesion. One effort to overcome the limitation of the high water capacity of cellulose is its incorporation with other films, resulting in higher tensile strength, higher lipid resistance, and improved barrier properties to water [62,63]. Some of the most usable derivatives of cellulose are cellulose acetate, nitrate, sulfate, carboxymethyl, methyl, and ethyl nano-cellulose [64]. These have many advantages, such as edibility, biodegradability, bioavailability, non-toxicity, light weight, and pleasant organoleptic characteristics (color appearance, taste, aroma, and flavor), and they can be easily found at a low cost. In addition, cellulose can be incorporated and encapsulated with various active molecules of antimicrobials and antioxidants [65,66]. Cellulose derived from bacteria has extraordinary properties in comparison to other polysaccharide-based polymers. In the food industry, derivatives of cellulose are used as thickening and gelling agents, stabilizers, water-binding additives, and food packaging materials [67].

Hemicellulose (also known as polyose) is a polysaccharide often related to cellulose but with a distinguishable composition and structure. Hemicellulose is biosynthesized of diverse monosaccharides and can contain xylose and arabinose, glucose, mannose, galactose, and rhamnose. Hemicellulose includes most of the D-pentose monosaccharides and occasionally small amounts of L-monosaccharides as well. Xylose is, in most cases, the monosaccharide monomer that is found in the highest quantity, although in softwoods, mannose can be the most abundant monosaccharide. It is worth mentioning that acidified forms of regular monosaccharides can be found in hemicellulose, including glucuronic acid and galacturonic acid [68].

Given its branched and amorphous structure, unmodified hemicellulose films do not have advanced mechanical properties. Casting and drying methods have been used for the hemicellulose-based film production [69]. Moreover, the presence of a hydroxyl group makes it more susceptible to moisture absorption. The improvement of the mechanical and barrier properties of hemicellulose films can be achieved by physical and chemical modifications [70]. The addition of plasticizers such as sorbitol and glycerin in composite films (hemicelluloses–chitosan) resulted in improved barrier properties and elongation at break but reduced tensile strength. However, we must stress that the additions of plasticizers may result in increased moisture absorption due to the hydrophilic nature of plasticizers. To eliminate water absorption and increased hydrophobic nature, researchers have adopted etherification with galactoglucomannan (GGM) given that the butyl glycidyl ether provides better thermal and mechanical properties [71].

Chitosan is a linear polysaccharide that consists of D-glucosamine and N-acetyl-D-glucosamine linked with a β-(1→4) glycoside bond. Chitosan is produced by chitin after alkaline treatment with sodium hydroxide. Chitin is a polysaccharide found in the exoskeleton of arthropods, the cell wall of some fungi, the gladii of mollusks, cephalopods beaks, radulae, and in some nematodes and diatoms. The presence of amino and hydroxyl groups in the molecular structure of chitosan enhances its ability to inhibit the growth of Gram-positive and Gram-negative bacteria.

Chitosan can be used in agriculture as a seed treatment and biopesticide. In winemaking, it can be used as a refinement agent. In the coating industry, it can be used in a self-healing polyurethane paint coating. In medicine, it is used as bandages and as an antibacterial agent. Chitosan can also contribute to the delivery of medicines through leather. Films made from chitosan possess high antimicrobial and antioxidant properties and are widely used in food packaging. The main mechanisms of the antimicrobial action of chitosan are the following:

• The change of the bacterial cell wall charges are because of the interactions of its constituents with the amino groups of chitosan, resulting in the transfer of intracellular fluid to the environment, finally leading to the death of cells [72];
• The formation of thin cellophane films on food surfaces is a result of the prevention of microbial attack and the exclusion of oxygen, resulting in the inhibition of aerobic microorganisms [73];
• Chitosan can bind essential trace metals that take part in the microbial metabolic pathway [74];
• Chitosan stimulates the synthesis of the chitinase enzyme that disrupts the fungal cell wall [75].

Films made from chitosan have high biodegradability and biocompatibility but also present disadvantages such as the low water barrier properties. This drawback can be limited by using mixtures of chitosan with bio-proteins. Except for the barrier properties, compatibility and thermal stability are also improved [73]. The blend of chitosan with other biomaterials, nanometals, and active compounds also increases the moisture barrier and mechanical properties [76]. Studies have shown that the incorporation of various essential oils in packaging materials based on chitosan/gelatin causes an increase in mechanical resistance by 30% and a reduction in its flexibility [77]. No significant changes were exhibited in water barrier properties [77,78,79]. Furthermore, no significant changes were presented in thermal stability [77,80,81]. It is worthy of note that ε-polylysine blended with chitosan contributed to the shelf-life extension of beef fillets and the increase in its storability under refrigeration [82].

Alginates are the sodium, potassium, or calcium salts of alginic acid. Alginic acid, i.e., algin, is an edible polysaccharide that is found in brown algae. It has a high hydrophilicity and is capable of entrapping water molecules in its three-dimensional net, resulting in the formation of a viscous gum. Alginic acid’s color ranges from white to yellowish-brown, and it is sold in filamentous and granular forms. It is worth noting that algin is an important constituent of the biofilms produced by the bacterium Pseudomonas aeruginosa, which is found in the lungs of some people who suffer from cystic fibrosis [83,84,85].

Alginic acid is a linear copolymer that consists of (1→4)-linked β-D-mannuronate and α-L-guluronate residues. The refinement of alginates is performed using brown seaweeds. The most commonly used alginate is the sodium alginate that is used widely in the food industries as a thickener and stabilizer and as animal food as well as for fertilizers, textile printing, cosmetics, and pharmaceuticals [83,86,87,88]. The most popular seaweed that is used for the refinement of alginates is the giant kelp Macrocystis pyrifera, whose length can reach 20–40 m. There are also seaweeds of smaller length that are used for the isolation of alginates, such as Ascophyllum nodosum and types of Laminaria.

Due to the film-forming properties of alginates, such as their hydrophilicity and biocompatibility, they are extensively used in the preparation of edible coatings [89,90]. However, alginates have also some drawbacks that have limited their usage in food preservation, such as low resistance to UV radiation, water barrier properties, and high sensitivity to microbial growth. Some studies have been performed to determine the limitations of these disadvantages. The addition of aloe vera and frankincense oil in the film made from alginate produced better mechanical and moisture barrier properties, thermal stability, antimicrobial activity, and higher UV shielding [91]. The moisture-barrier properties of alginate and starch-based films can also be increased by the incorporation of microcrystalline cellulose [92]. Mechanical and antibacterial properties have also been improved by the incorporation of silver nanoparticles and lemongrass essential oil [93].

The application of alginate-based film with added aloe vera and frankincense oil to the packaging of green capsicum retarded their senescence and decreased their weight loss. In addition, the packaging of apple slices with alginate-based films incorporated with phenolic compounds such as thymol caused a significant inhibition to the growth of Staphylococcus aureus and Escherichia coli, decreased weight loss, increased the retention of nutrients, and maintained the surface color of apple slices [94].

Carrageenans are a group of natural linear sulfated polysaccharides that are refined from red edible seaweeds such as Chondrus crispus, which are the most popular red edible seaweeds used to produce carrageenan. Carrageenans are widely used in the food industry because of their high gelling, thickening, stabilizing abilities, protective coating, and fat substitution capabilities [95]. These are also used successfully in dairy and meat products due to their strong binding to food proteins.

Chemically, carrageenans consist of sulfated polysaccharides. Carrageenan molecules have high flexibility and form curling helical structures. There are three main groups:

• Kappa-carrageenan has one sulfate group per two repeating units and forms strong, rigid gels along with potassium ions and reacts with dairy proteins. It is obtained mainly from Kappaphycus alvarezii [96];
• Iota-carrageenan has two sulfate groups per two repeating units and forms fewer rigid gels along with calcium ions. It is obtained mainly from Eucheuma denticulatum [96];
• Lambda-carrageenan has three sulfate group per two repeating units and does not form gel, whereas it is used to thicken dairy products such as skim milk, cream cheese, yogurt, and sour cream.

Carrageenan is nontoxic and has high biocompatibility and biodegradability. Carrageenan offers higher stability of capsules, higher electronegativity, and better protection of encapsulated materials in comparison with other encapsulation matrices [97]. The difference in the structure of carrageenan compared to other polysaccharides gives the latter different biological activities, such as antioxidant, antitumor, immunomodulatory, anti-inflammatory, anticoagulant, antiviral, antibacterial, antifungal, and anti-hyperglycemic properties [5]. Many researchers have developed pH-sensitive and antioxidant-packaging carrageenan-based films that have been used in the encapsulation of fish oil and enriched nuggets, thus exhibiting positive results in lipid and protein oxidation [98,99].