Effect of Cold Plasma Treatment on the Packaging Properties of Biopolymer-Based Films: A Review

Abstract

Biopolymers, like polysaccharides and proteins, are sustainable and green materials with excellent film-forming potential. Bio-based films have gained a lot of attention and are believed to be an alternative to plastics in next-generation food packaging. Compared to conventional plastics, biopolymers inherently have certain limitations like hydrophilicity, poor thermo-mechanical, and barrier properties. Therefore, the modification of biopolymers or their films provide an opportunity to develop packaging materials with desired characteristics. Among different modification approaches, the application of cold plasma has been a very efficient technology to enhance the functionality and interfacial characteristics of biopolymers. Cold plasma is biocompatible, shows uniformity in treatment, and is suitable for heat-sensitive components. This review provides information on different plasma generating equipment used for the modification of films and critically analyses the impact of cold plasma on packaging properties of films prepared from protein, polysaccharides, and their combinations. Most studies to date have shown that plasma treatment effectively enhances surface characteristics, mechanical, and thermal properties, while its impact on the improvement of barrier properties is limited. Plasma treatment increases surface roughness that enables surface adhesion, ink printability, and reduces the contact angle. Plasma-treated films loaded with antimicrobial compounds demonstrate strong antimicrobial efficacy, mainly due to the increase in their diffusion rate and the non-thermal nature of cold plasma that protects the functionality of bioactive compounds. This review also elaborates on the existing challenges and future needs. Overall, it can be concluded that the application of cold plasma is an effective strategy to modify the inherent limitations of biopolymer-based packaging materials for food packaging applications.

Effect of High-Pressure Processing on the Packaging Properties of Biopolymer-Based Films: A Review

“…Tensile strength (TS) and elongation at break (EAB) are critical mechanical properties associated with the performance of automatic packaging lines and also maintain food quality and integrity during handling, processing, shipping, and storage [ 4 , 18 ]. HPP of FFS can cause the volume-driven transition, promotes cross-linking, and induces phenomena such as protein denaturation or starch gelatinization that can affect the mechanical properties of the films [ 29 , 30 , 31 , 34 , 37 ].…”

“…Assessing these parameters can determine structural and thermal changes induced by HPP. These parameters are also significant to determine the processing conditions of biopolymers and their applications in packaging, like heat sealing [ 18 , 47 ]. Table 1 summarizes the thermal properties of HPP in the preparation of biopolymer-based films.…”

“…Although conventional plastics demonstrate excellent suitability for HPP, these are non-biodegradable and non-renewable. The large application has raised plastic production and its worldwide production was 368 million metric tons in 2019 and has been continuously growing at 4% every year [ 18 , 19 ]. The critical point of high plastic production is the manufacturing of single-use plastics (almost 50%) that cause the issue of plastic pollution and its waste management.…”

“…Only 9% of all the plastics get recycled and the rest ends in the land fields and water bodies. This high production of plastics is not only a serious threat to individuals, or communities but to the whole ecosystem, especially the marine ecosystem [ 18 , 20 ].…”

Mechanical, Barrier, Antioxidant and Antimicrobial Properties of Alginate Films: Effect of Seaweed Powder and Plasma-Activated Water

“…The application of cold plasma (CP) has been reported to enhance the functional and antimicrobial properties of biopolymers [ 35 , 36 ]. CP is a sustainable non-thermal disinfection and surface modification method [ 37 ].…”