Novel biopolymer-based sustainable composites for food packaging applications: A narrative review

Sustainable chitosan films containing a betaine-based deep eutectic solvent and lignin: Physicochemical, antioxidant, and antimicrobial properties

Development and characterization of sodium alginate/tea tree essential oil nanoemulsion active film containing TiO2 nanoparticles for banana packaging.

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.

https://www.mdpi.com/2076-3417/12/3/1346/pdf?version=1643348726

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

To find renewable and sustainable alternatives to reduce the severe environmental impact of single-use synthetic plastic packaging, glucose-crosslinked gelatin films containing different amounts of chitin nanowhiskers (CNWs) were prepared. CNWs were first prepared by acid hydrolysis of chitin from shrimps, and characterized (morphological and thermal properties), before their addition into film-forming formulations. The films were heat-treated to promote the chemical crosslinking Maillard reaction (MR), between glucose and gelatin. The films then became less soluble (from 100% to ∼10%), thermally more stable, had a notably improved UV–vis light absorption capacity, and presented significantly enhanced tensile strength (from 42 to 77 MPa) and Young's modulus (from 1476 to 2921 MPa), however, they also became less flexible (from 17% to 7%) and transparent. These property alterations were mainly related to changes in crystallinity, the MR and to a lesser extent, to the formation of noncovalent (electrostatic and hydrogen bonding) interactions between CNWs and gelatin. Furthermore, due to the formation of MR products, the films turned yellow/dark brown and released antioxidant compounds (inhibition ∼33%) while immersed in water, which gave the films their active properties (stabilization of free radicals). These films have considerable potential as reinforced active packaging films for renewable food packaging applications.

Characterization of glucose-crosslinked gelatin films reinforced with chitin nanowhiskers for active packaging development

Recent advances in biopolymeric antioxidant films and coatings for preservation of nutritional quality of minimally processed fruits and vegetables

There is an urgent need to increase the food supplies to fulfil the demands of future generations as the population of the world is expected to grow beyond 10 billion by 2050. An essential component for ensuring global food security is to reduce food losses during the post-harvest stage. Active edible coatings and films are a promising sustainable preservation technology for shelf-life extension of food products by hindering decay kinetics of minimally processed fruits and vegetables (F&V), by restricting the mass transfer of moisture, aroma, or gases and carrying an active compound, such as an antioxidant or antimicrobial. Active protein-based coatings and films have the potential to extend the shelf-life of food products by decreasing their respiration rates, as they exhibit an excellent gas barrier and good mechanical properties as compared to other biopolymeric packaging. Among protein-based biopolymers, casein and its derivatives as packaging films have been extensively studied due to their low cost, complete biodegradability, and availability. Currently, there is no review study focusing on caseinate-based active coating and film, thus, this review aims to give insights on the composition, rheology, structure, and properties of caseinate-based formulations by critically discussing the results presented in the literature. A methodological approach was followed to obtain relevant literature to discuss the influence of additives on the shelf-life of F&V. Furthermore, changes in secondary structure of casein were observed after incorporation of bioactive compounds (i.e., phenolic acids). Likewise, there is a need to explore chemical interactions among bioactive compounds and biopolymer material by using in silico and laboratory trials as food additives have shown to influence the physicochemical properties of film and shelf-life of food products.

/pdf/active-casein-coatings-and-films-for-perishable-foods-3me6gu2olf.pdf

Muhammad Rehan Khan

Papers

Recent advances in biopolymeric antioxidant films and coatings for preservation of nutritional quality of minimally processed fruits and vegetables

Active Casein Coatings and Films for Perishable Foods: Structural Properties and Shelf-Life Extension