A Review on Antimicrobial Packaging from Biodegradable Polymer Composites

The development of antimicrobial packaging has been growing rapidly due to an increase in awareness and demands for sustainable active packaging that could preserve the quality and prolong the shelf life of foods and products. The addition of highly efficient antibacterial nanoparticles, antifungals, and antioxidants to biodegradable and environmentally friendly green polymers has become a significant advancement trend for the packaging evolution. Impregnation of antimicrobial agents into the packaging film is essential for impeding or destroying the pathogenic microorganisms causing food illness and deterioration. Higher safety and quality as well as an extended shelf life of sustainable active packaging desired by the industry are further enhanced by applying the different types of antimicrobial packaging systems. Antimicrobial packaging not only can offer a wide range of advantages, but also preserves the environment through usage of renewable and biodegradable polymers instead of common synthetic polymers, thus reducing plastic pollution generated by humankind. This review intended to provide a summary of current trends and applications of antimicrobial, biodegradable films in the packaging industry as well as the innovation of nanotechnology to increase efficiency of novel, bio-based packaging systems.

Green Coating Polymers in Meat Preservation

Edible coatings, including green polymers are used frequently in the food industry to improve and preserve the quality of foods. Green polymers are defined as biodegradable polymers from biomass resources or synthetic routes and microbial origin that are formed by mono- or multilayer structures. They are used to improve the technological properties without compromising the food quality, even with the purpose of inhibiting lipid oxidation or reducing metmyoglobin formation in fresh meat, thereby contributing to the final sensory attributes of the food and meat products. Green polymers can also serve as nutrient-delivery carriers in meat and meat products. This review focuses on various types of bio-based biodegradable polymers and their preparation techniques and applications in meat preservation as a part of active and smart packaging. It also outlines the impact of biodegradable polymer films or coatings reinforced with fillers, either natural or synthesized, via the green route in enhancing the physicochemical, mechanical, antimicrobial, and antioxidant properties for extending shelf-life. The interaction of the package with meat contact surfaces and the advanced polymer composite sensors for meat toxicity detection are further considered and discussed. In addition, this review addresses the research gaps and challenges of the current packaging systems, including coatings where green polymers are used. Coatings from renewable resources are seen as an emerging technology that is worthy of further investigation toward sustainable packaging of food and meat products.

Development and potential applications of gelatine, honey, and cellulose electrospun nanofibres as a green polymer

Nanofibres have emerged as a brilliant technology to be applied in various areas due to their excellent properties that include having a great flexibility, prominent specific surface area and structural strength. Electrospinning is one of the most effective and favourable methods to fabricate nanofibres mainly because electrospun nanofibres have been demonstrated to possess small pore sizes, large specific surface area, and can be produced with different functions to fill the need of various applications in industries. Due to their remarkable properties, electrospun nanofibres have been proven to be suitable for applications in food packaging, medical, pharmaceutical and even in tissue engineering. Currently, there have been numerous research utilising both electrospun synthetic and natural polymers. Natural or green polymers are considered more favourable due to their biodegradable properties and potential biocompatibility. Therefore, there has been a shift to include more research regarding these green polymers. Green polymers can source from both plant polysaccharides and animal protein. Considering the different characteristics of synthetic polymers, the processing and fabrication methods may differ and must be adjusted accordingly. To well summarise the development of these green polymer nanofibres, we review fabrication methods of gelatine, honey and cellulose-based nanofibre and their potential applications in industries. There are indeed numerous promising areas for the usage of these green polymers which are based on their splendid individual properties especially when combined to form nanofibres via electrospinning. We hope this will promote continuous research and development for the applications in various industries including but not limited to tissue engineering, biomedical, food and pharmaceutical industries.

Experimental Evaluation of Hydrotreated Vegetable Oils as Novel Feedstocks for Steam-Cracking Process

Hydrotreated vegetable oils (HVOs) are currently a popular renewable energy source, frequently blended into a Diesel-fuel. In the paper, HVO potential as feedstock for the steam-cracking process was investigated, since HVOs promise high yields of monomers for producing green polymers and other chemicals. Prepared HVO samples of different oil sources were studied experimentally, using pyrolysis gas chromatography to estimate their product yields in the steam-cracking process and compare them to traditional feedstocks. At 800 °C, HVOs provided significantly elevated ethylene yield, higher yield of propylene and C4 olefins, and lower oil yield than both atmospheric gas oil and hydrocracked vacuum distillate used as reference traditional feedstocks. The HVO preparation process was found to influence the distribution of steam-cracking products more than the vegetable oil used for the HVO preparation. Furthermore, pyrolysis of HVO/traditional feedstock blends was performed at different blending ratios. It provided information about the product yield dependence on blending ratio for future process design considerations. It revealed that some product yields exhibit non-linear dependence on the blending ratio, and therefore, their yields cannot be predicted by the simple principle of additivity.

Green Polymers and Their Uses in Petroleum Industry, Current State and Future Perspectives

The concept of green chemistry has been established to find safe methodologies and environmentally benign solutions for the present and the onset problems. In this regard, extensive work has been carried out worldwide to replace the currently used materials with green ones. The terminology green relies on all the non-pollutive or the degradable materials regardless of their source. Therefore, there are biobased green materials and non-biobased green materials. This review sheds light on several green polymers used in different petroleum industries. The polymers are reviewed according to the stage of oil processing in which they are applied. Furthermore, different modification methodologies of natural polymers are revised. Also, the role of green non-biopolymers in different petroleum industries is investigated. It is worth mentioning that we concentrate our efforts on the utilization of different natural polymers in petroleum applications. Thereafter, some natural polymers such as chitosan and cellulose and their derivatives were specifically reviewed.

Epoxidation of Terpenes

Terpene epoxides are considered as potential primary intermediates in the synthesis of numerous green polymers including epoxy resins, polycarbonates, nonisocyanate polyurethanes and even some polyamides. In this chapter we describe recent efforts from our group to develop catalytic and noncatalytic processes for terpene epoxidation using a variety of oxidizing agents and process intensification methods. Most experimental tests deal with limonene epoxidation with applicability to some other terpenes also demonstrated.

Study of the Direct CO2 Carboxylation Reaction on Supported Metal Nanoparticles

2,5-furandicarboxylic acid (2,5-FDCA) is a biomass derivate of high importance that is used as a building block in the synthesis of green polymers such as poly(ethylene furandicarboxylate) (PEF). PEF is presumed to be an ideal substitute for the predominant polymer in industry, the poly(ethylene terephthalate) (PET). Current routes for 2,5-FDCA synthesis require 5-hydroxymethylfurfural (HMF) as a reactant, which generates undesirable co-products due to the complicated oxidation step. Therefore, direct CO2 carboxylation of furoic acid salts (FA, produced from furfural, derivate of inedible lignocellulosic biomass) to 2,5-FDCA is potentially a good alternative. Herein, we present the primary results obtained on the carboxylation reaction of potassium 2-furoate (K2F) to synthesize 2,5-FDCA, using heterogeneous catalysts. An experimental setup was firstly validated, and then several operation conditions were optimized, using heterogeneous catalysts instead of the semi-heterogeneous counterparts (molten salts). Ag/SiO2 catalyst showed interesting results regarding the K2F conversion and space–time yield of 2,5-FDCA.