A Study on Edible Polymer Films for Food Packaging Industry: Current Scenario and Advancements

*Deepak R. Kasai, Devi Radhika, Raju K. Chalannavar, Ravindra B. Chougale and Bhagyavana Mudigoudar*

### **Abstract**

Over the past two decades, food packaging and packaging industry have paid close attention to create biodegradable and edible polymer films and coatings. In a broad way, edible polymers emerged as a new class of materials that garnered significant properties due to their advantages over synthetic petroleum-based films. When compared to conventional packaging materials, edible polymer films can fundamentally simplify products, improving their potential to be recycled. This work aims to give readers a thorough introduction to edible polymer films, by discussing present research trends, classification, functionality and composition, fabrication, and characterization. The work also emphasizes the advantages and disadvantages of edible polymer films based on meat, poultry, dairy products, fruits, nuts, and vegetables.

**Keywords:** edible polymer, coatings, food packaging, antimicrobial, functionality, applications

#### **1. Introduction**

Many efforts have been made to create eco-friendly packaging material in response to the challenges caused by plastic waste in the packaging business. Food packaging is critical for storing foods, protecting them from infection, and maintaining food quality throughout the packaging-to-consumption process [1]. Several types of plastics are being used as packaging material due to their low cost, high performance, and easy production. Almost half of the packaging materials used in single-use throwaway applications, particularly food packaging, are produced from petrochemical polymers, such as plastics [2]. However, petrochemical plastics have a number of drawbacks, including environmental challenges, health dangers, and poor food quality due to their non-biodegradability [3, 4]. Also, production and consumption of plastics in the last few decades has put enormous stress on the environment by releasing plastic waste. Thus, there is a need to look for alternative packaging materials that should not

impose any problems, renewable, disposable, recyclable, and easily degradable [5]. A thin coating that covers the food surface is known as an edible package.

The growing demand for high-quality products with a long shelf life has led to the development of new processing technologies that guarantee natural qualities and appearance. As a result, the packaging industry as well as a number of young researchers are attempting to develop edible polymer films as biodegradable packaging materials [6]. In this case, edible polymer films would be an excellent choice for packaging. Edible polymers can be taken whole or in part by humans and lower animals through the oral cavity, with no negative health effects. Many advantageous properties, such as non-pollutant products, since they contain natural and biodegradable components generated from both natural and manmade materials are considered. Edible polymers have emerged as a suitable candidate for food packaging applications and have received significant attention in recent years [7]. The requirements imposed on edible polymer films were exclusively based on the product's specific qualities and changes in those attributes throughout production and storage [8]. Edible polymers have the ability to expand organoleptic properties of packaged foods materials. As the author reported, edible polymer has properties, such as flavorings, colorings, and sweeteners. Natural polymers and food-grade additives have become increasingly popular in the medical and food industries. Polysaccharides, proteins, and lipids, as well as plasticizers and surfactants, can be used to make these edible polymers. The ability of edible polymers is primarily determined by their barrier, mechanical, and color properties, which are influenced by the film composition and production procedure.

### **2. Edible polymer films: present research trends**

In recent years, the use of edible films made from natural polymers and foodgrade additives has steadily increased. Various materials, including polysaccharides, proteins, lipids, and resins, can be used to make these films, either with or without the inclusion of other ingredients (e.g., plasticizers and surfactants) [9, 10]. The moisture barrier performance of polysaccharide-based films is typically subpar, but they exhibit selective O2 and CO2 permeability and oil resistance [11]. Edible films can be fabricated based on cellulose, starch (natural and modified), pectin, seaweed extracts (alginates, carrageenan, and agar), gums (acacia, tragacanth, and guar), pullulan, and chitosan [12]. Films are made harder, crisper, more compact, viscous, sticky, and capable of producing gels; thanks to these substances. Other significant sources of polysaccharide-based biomaterials have been regarded as marine creatures, such as seaweed, bacteria, and microalgae [13, 14]. Moreover, edible polymers needed to meet a variety of requirements in order to be used as packaging and food components, including high barrier and mechanical efficiency, biochemical, physicochemical, and microbiological stabilities, as well as being nontoxic, nonpolluting, and inexpensive [15]. An emerging area of study in material science is the inclusion of active compounds derived from industrial wastes into edible films. Furthermore, inclusion of active components derived from industrial wastes become a hot area in materials research [16]. It was discovered that edible films may operate as transporters of active substances, such as antioxidants, antimicrobials, and texture enhancers [17], and many methods of obtaining them have been published.

In the past several years, the food industry has employed a lot of edible films made from polysaccharides (cellulose, starch, pectin, seaweed, gums, chitosan, and

### *A Study on Edible Polymer Films for Food Packaging Industry: Current Scenario… DOI: http://dx.doi.org/10.5772/intechopen.107997*

pullulan), but lignocellulosic materials have just recently been shown to be viable for making edible films. Authors Slavutsky and Bertuzzi have reported starch films reinforced with cellulose nanocrystals derived from sugarcane bagasse [18]. In addition, Shimokawa et al. used hemicellulose fractions from Pinus densiflora leaves to create translucent and transparent films [19]. The compounds these authors obtained have high promise as edible films and characteristics resembling those of xylan. By using acid hydrolysis to separate crystalline cellulose nanofibrils from cotton linter, composite films with pronounced improvements in optical and mechanical properties, water vapor barrier qualities, and thermal stability were created [20]. Alginate-carbohydrate solutions containing 5% alginate and 0.5% pectin, carrageenan (or), potato starch (modified or unmodified), gellan gum, or cellulose were used to make composite alginate films (cellulose extracted from soybean chaff or commercial cellulose) [21]. With the alginate matrix, all of those carbohydrates were able to create composite films. However, using the cellulose from soybean chaff could result in composite films or casings made of alginate that have mechanical properties comparable to those of microcrystalline cellulose used in commercial products. **Table 1** represents the various edible films prepared using polymer and essential oils and other components.

Industry research futures (MRFR) predicts that the edible packaging market (based on protein, lipids, polysaccharides, and others) would be worth USD 2.14 billion by 2030, up from USD 783,32 million in 2021, with a compound annual growth rate (CAGR) of 6.79 percent (2022–2030). Throughout the projection period,



#### **Table 1.**

*Various edible polymer films, fabrication techniques observed remarks.*

north America will dominate the edible packaging market, followed by the United Kingdom, Japan, Indonesia, and Israel [32]. In order to enable their commercial implementation, researchers have been working nonstop for the past three decades to create edible films that can compete with traditional plastic films. Meanwhile, the packaging sector faces challenges in the areas of high moisture content, high pressure and modified atmosphere, natural and fresh goods, among others, and with an environmentally friendly approach [33].

### **3. Classification**

Films and coatings are made from edible polymers and material composition, as well as the material thickness, differs between the two. Bags, pouches, capsules,

#### *A Study on Edible Polymer Films for Food Packaging Industry: Current Scenario… DOI: http://dx.doi.org/10.5772/intechopen.107997*

and casings are all made with films. Coatings are also applied directly to the surface of the meal. Hydrocolloids, lipids, and their composites are the three types of edible polymers. Hydrocolloids are long-chain hydrophilic polymers. The texture (chewy or creamy, lengthy or spreadable, and elastic or brittle) and sensory qualities (taste, mouth feel, and opacity) of the gel vary depending on the kind of hydrocolloid. Because of its hydrophilic feature, it can create viscous dispersion or gels in water. This is because the hydrocolloid's hydroxyl group bonds with water molecules, thickening the water or forming gels. They are weak water barriers because they can capture or immobilize water molecules in a three-dimensional network.

Fatty acids containing carbon atoms [34–38] generated from vegetable oils and waxes make up the other family of lipids [3]. They are generally opaque, waxy tasting, and slippery, and can be used to adjust color, flavor, sweetener, and salt concentrations, among other things [39]. Lipids are hydrophobic by nature, making them effective water vapor barriers with minimal permeability. The water permeability of edible composites made of hydrophilic hydrocolloids and hydrophobic lipids can be enhanced by combining them.

Based on their main components, edible films and coatings are divided into different categories. There are four major categories of edible coatings and films, including polysaccharides, proteins, lipids, composites, and polymers. **Figure 1** summarizes the classifications of edible films fabricated from various materials [40].

#### **3.1 Polysaccharide-based edible films**

The most prevalent natural polymer is polysaccharide, and in recent years, it has been frequently employed to create edible films or coatings. It is well known that polysaccharides contain a strong oxygen barrier and sites for the creation of hydrogen bonds, which can be exploited to incorporate functional ingredients including taste, coloring, and antioxidant compounds. These materials lack effective water

**Figure 1.** *Classification of edible films [40].*

vapor barriers, however, this problem can be solved by combining them with other hydrophobic macromolecules, such as lipids [41, 42]. Natural-based packaging has been created using polysaccharides [43]. Edible films and coatings are created using polysaccharides, including starch, pectin, cellulose, exudate gums, and seaweed extracts. After considering their suitability in terms of the physical, mechanical, and functional characteristics of edible films and coatings, these substances are chosen. Although polysaccharide-based films and coatings have poor moisture barrier qualities, they are only slightly more permeable to oxygen and selectively permeable to oxygen (O2) and carbon dioxide (CO2) than other materials. Because they can alter the atmosphere inside the product, they are useful for the preservation of fruits and vegetables where they can lower the respiration rate. Pea starch-based edible films improved the use of pea starch in both food and non-food applications when guar gum and glycerol were added [44]. Edible films made of polysaccharides have a wellorganized hydrogen-bonded network, which makes them effective oxygen blockers. Polysaccharide coatings are used to enhance the shelf life of products without causing any anaerobic conditions. They are colorless, free of oil, and have no oil content [41]. One can prepare the polysaccharide-based film either wetly or dryly. Several authors created polysaccharide-based edible films and coatings. Author Arantzazu Valdes et al. have created the natural pectin polysaccharides as edible coatings to improve organoleptic and nutritional characteristics and extend shelf-life [45]. Author Aarushi et al. has prepared Seaweed polysaccharide-based edible coatings and films. Authors emphasized the structure, extraction, and gelling mechanism of the alginate and carrageenan with incorporation of additives, such as plasticizers, nutraceuticals, flavors, and surfactants in the films [46]. Also, Prerna Singh et al. have prepared starch-based edible films with the objective of standardizing the production methodology and formulation for the creation of starch-based biodegradable antimicrobial films to increase the shelf-life of food and food items [47]. Similarly, author Poonam Singh et al. have developed cellulose-based films cross-linked with citric acid for probiotic entrapment. Authors concluded the probiotic bacteria were successfully entrapped into the films with acceptable viability [48]. All of these properties of polysaccharide coatings and edible films can extend fruit shelf life [41]. Alginate is a polymer found in brown algae (Phaeophyceae). Alginate consist of α-L-guluronate (G) and R-D-mannuronate (M) links in th (1–4) chain [41, 49]. Pullulan, a polysaccharide with microbial qualities comprised of maltotriose and (1,6) glycosidic units generated by Aureobasidium pullulans from starch [10], is another polymer with microbial features. Pullulan is a water-soluble, colorless, odorless, and tasteless edible film that is also oil permeable and heat sealable [41].
