Polysaccharides as Edible Films and Coatings: Characteristics and Influence on Fruit and Vegetable Quality—A Review

Abstract

There has been a significant increase in the development of edible films and coatings in recent times, and this is expected to have a significant impact on the quality of fruit and vegetables in the coming years. Consumers expect fresh fruit and vegetables free from pesticide residues, with high quality, nutritional value and an extended shelf life. The application of coatings and edible films to fruits and vegetables represents an environmentally friendly approach to an innovative solution to this problem. Coatings and edible films can act as ecological and biodegradable packaging. The coating strategy involves a combination of natural biopolymers and appropriate preservation methods. The article presents the applicability, trends and perspectives of polysaccharide coatings and edible films and their impact on the quality of fruit and vegetables, providing an understanding of their main functions and benefits. Numerous studies show that natural polysaccharides are well suited for use as packaging material for fresh fruit and vegetables and can often be an important alternative to synthetic compounds. Natural polymer materials are a good barrier to oxygen and carbon dioxide; however, they are characterised by excessive solubility in the water environment, water vapour permeability and low extensibility. The properties of edible coatings can be modified by the addition of plasticisers, surfactants, cross-linkers, antimicrobial agents, functional additives, nanosilver particles or fruit and vegetable residues. The use of an electric field is also a promising technology here. The use of polysaccharides for the preparation of edible films and coatings is justified not only by the possibility of reducing the consumption of packaging made of synthetic polymer materials but also by the fact that the production of some natural polymers can be made using waste products generated during the processing of food raw materials.

Process Parameter Optimization and Characterization for an Edible Film: Flaxseed Concern

“…This increased value for the control sample may be attributed to pectin agglomeration below the film, or due to the uneven casting of the film. Pectin significantly affects the transparency of the edible film, as reported by other authors [10,12]. In contrast, the film prepared with only flaxseed (test-2) showed a poor transparency, with a value of 44.63.…”

“…Plant-based edible coatings and films are a sustainable alternative to plastic packaging [10]. Pectin, owing to its polymerized structure and cementing attributes, works well as a base ingredient for developing an edible package [11,12].…”

Lipid-Polymeric Films: Composition, Production and Applications in Wound Healing and Skin Repair

“…The barrier property of lipid films for the transfer of gases, such as oxygen and carbon dioxide, is very low when compared to films of some hydrocolloids (proteins and polysaccharides) [55], and also lower in the order of 3000 times when compared to some synthetic polymers. Many lipids, especially unsaturated ones, are subject to lipid oxidation, in the presence of oxygen, resulting in rancidity with the formation of compounds with undesirable odors [57].…”

“…The films obtained from natural polymers are characterized by their hydrophilic nature, which promotes their affinity with water, increasing the permeability to water vapor [55,56]. The polysaccharides generally used in the formulation of films are characterized by their selective permeability to gases, but a reduced property of water vapor barrier, due to the hydrophilic nature of these polymers [30,[57][58][59][60].…”

“…These properties are directly related to the filmogenic structure, i.e., to the bonds present in the matrix. The stress at break is the maximum tensile force that the film can sustain before breaking, and is directly related to the order of magnitude of the energy in the intermolecular bonds present in the polymeric matrix [55,74]. The percentage of elongation corresponds to the maximum variation in the length of the sample before breaking or breaking, i.e., it measures the stretching capacity [75].…”