Sustainable packaging in the food chain
Recently, there have been a number of news items related to sustainable packaging. Here we shortly present some of them.

New EU rules to allow of recycled plastics in food packaging

The European Union (EU) has adopted new rules on the safety of recycled plastic materials to ensure that recycled plastic can be safely used in food packaging. The new Regulation aims to increase the overall sustainability of the food system and achieve the objectives of the 'Circular Economy Action Plan'. The regulation makes it possible to authorize recycling processes for manufacturing safe recycled plastic materials for use in food packaging. It will also help the recycling industry establish suitable ways for recycling plastics that presently cannot be recycled into food packaging. Additionally, the European Food Safety Authority (EFSA) will have a clearer basis to evaluate the suitability of recycling technologies and the safety of the recycled plastic in food packaging. The Regulation will allow granting individual authorizations for more than 200 mechanical PET (polyethylene terephthalate) recycling processes, which will help the industry to meet the binding 2025 target of 25% recycled plastic in PET beverage bottles. Furthermore, the new Regulation will establish a public register of recycling processes, recyclers, and recycling installations under its scope, providing an increased level of transparency. In conclusion, this is an essential step towards safe and sustainable use of recycled plastics in the food sector and building a fully circular economy.

Recent advances in bio-based smart active packaging

The use of renewable resources instead of non-renewable resources in the food industry has become one of the hottest topics of research. There is growing interest in the development of bio-based intelligent active packaging that is in line with the concept of sustainability and guarantees safety. The antibacterial and antioxidant properties of packaging extend the shelf-life of food and the ability to monitor the freshness of food in real time is beneficial to consumers in their perception of food safety. Biodegradable natural polymers are better suited to sustainable development requirements and are therefore a better choice for food packaging materials. Antimicrobial packaging materials inhibit the growth of micro-organisms and extend the shelf life of food, but do not prevent food spoilage. Smart packaging, which can detect and monitor changes inside food, has been developed to solve this problem. Protein-based substances include whey protein, collagen, zein and soy protein isolate, while polysaccharide-based substances include starch, chitosan, sodium alginate and pullulan.

Coating with biodegradable antimicrobial pullulan fibres

Food waste and food safety require better food packaging solutions. However, current films/coatings that address these issues are often limited by inefficient release dynamics requiring large amounts of active ingredient. Researchers have developed an antimicrobial pullulan fibre (APF)-based packaging that is biodegradable and capable of packaging food substrates, increasing their shelf life and enhancing their safety. The APFs were spun using a high-throughput system called focused rotary jet spinning, where the only solvent was water, which allowed the incorporation of naturally occurring antimicrobial active ingredients. Using avocado as a representative example, it was demonstrated that the shelf life of APF-coated samples was extended by inhibiting the growth of natural microflora compared to uncoated control samples. This research offers a promising technique for the production of scalable, low-cost and environmentally friendly biodegradable antimicrobial packaging systems.

‌New ‘spray-on wrapper’ might be a plastic-free food packaging alternative

Scientists from Rutgers and Harvard University have collaborated to develop a biodegradable spray-on food wrapper that can preserve the shelf-life of food, reduce food and plastic waste, and increase food safety. The wrapper's main ingredient is pullulan, an edible fiber that the U.S. Food and Drug Administration generally recognizes as safe. The biodegradable polymer and non-toxic solvents can be rinsed off with water. However, environmental toxicologist Nishad Jayasundara encourages further research to determine how these materials break down and their environmental impact. According to Jayasundra, additional research is needed to determine whether the 'rinsing' method of disposal of the spray-on wrapper causes the initial nontoxic materials to break down in potentially harmful ways.

Mars moves to paper packaging

In a significant development for the paper packaging industry, one of the world's largest confectionery companies is converting the packaging of its most popular chocolates to recyclable paper-based packaging.Mars, Snickers and Milky Way are set to switch from plastic to paper-based packaging for their brands, and will begin rolling out the new packaging in Australia in April 2023. Our paper-based packaging consists of 86 per cent paper, a thin plastic barrier to maintain product quality and freshness, seals and inks for labelling. Although the packaging has a very thin plastic barrier, it is still recyclable.

Environmentally friendly plastic bag that dissolves in water

According to an article published in 2018, researchers in Chile have invented a 100% natural plastic that is biodegradable in water. According to the article, the secret is limestone, which is not harmful to nature. The exact composition is not known, but the authors claim that the packaging material is polyvinyl alcohol, which is not made from petroleum but from a natural material (limestone). The safety of the product was demonstrated by drinking the substance dissolved in a glass of water. The product is patented.

A Hungarian inventor (Péter Lajter, Degraway Technologies) invented DAT1 on a similar principle. He started his experiments in his home in 2018 and has now developed a certified product, allegedly patent-protected, that is compatible with injection moulding machines in the plastic industry and degrades in a few days when exposed to moisture. The material is currently used to make cutlery and coffee capsules, the exact composition of which is not known, except that it is made from organic ingredients, free of mineral oil and plastic. A proprietary hydrophobic coating prevents degradation during use.

Innovators develop seaweed-based alternatives to plastic food wrappers

Researchers from Flinders University and „one – five”, a German biotech company, have developed a seaweed-based coating that can replace plastics used in fast food packaging. Many food containers and wrappers contain harmful plastics derived from fossil fuels that do not biodegrade and break into tiny microplastics that pollute the environment and harm marine ecosystems. The initiative aims to transform the global packaging and plastics industry by significantly reducing reliance on highly pollutive conventional plastic. Seaweed, a common name for thousands of marine plants and algae found in different water bodies, not only provides food and shelter for marine animals, but it can also help solve the plastic pollution problem. The main objectives of the proposed rules are to prevent the generation of packaging waste, to boost high-quality “closed loop” recycling, and to reduce the need for primary natural resources and create a well-functioning market for secondary raw materials that will increase the use of recycled plastics. The seaweed-based coating material they developed uses natural polymer rather than fossil fuel-based products. The new coating material is derived from sodium alginate — which is obtained from brown seaweed and typically used as a thickening agent, gelling agent, emulsifier, stabilizer, and texture-improver. Although the biomass for the new coating formulation is made from natural polymers extracted from seaweeds that are native to the South Australian coastline, it is also possible for other countries to adopt this technology.

Lamination of Cast Hemp Paper with Bio-Based Plastics for Sustainable Packaging

Composite laminate recycling and waste disposal routes remain a burden to existing systems, requiring special treatment and separation. The inclusion of a plastic layer is important for several key properties that are required for food safety, which in turn has made these products exceptionally hard to substitute in food packaging. Yet, the continued use of non-degradable commodity plastics is unsustainable. Were compared in a research the four most promising biodegradable and bio-based plastics that could replace non-degradable plastics in laminates. Polyhydroxyalkanoate (PHA), polylactic acid (PLA), polybutylene succinate (PBS), and polybutylene succinate adipate (PBSA) were applied as a direct melt coating on porous cast hemp papers. Biodegradation studies in composting conditions showed that PLA and PHA seem to degrade even faster than cellulose (hemp fibers), which resulted in rapid degradation above 20–25 days with complete designation at 40 and 50 days for cPLA1.5 and cPHA1.5, respectively. cPBSA1.5 and cPBS1.5 demonstrated much more gradual degradation and decomposed within 80 days. Biodegradation is influenced by many factors, such as microbial activity, soil moisture content, temperature, the pH of the environment, exposed surface area, the composition and molecular weight of the polymer, and crystallinity. Bioplastics need to have high-performance properties during use, which limits their degradability. While they are biodegradable, they do not meet various standards set for biodegradable materials, and manufacturers present them as compostable or industrially compostable, which allows them to degrade from 30 days up to half a year depending on specific conditions. However, if they are left in the environment degradation could take years.

Future research is needed to determine how the sustainability performance of bio-based plastics can benefit the food packaging sector compared to conventional plastics.

Packaging material containing zeolite-thymol nanohybrid to improve shelf life

With the aim of improving the shelf life of food and replacing chemical substances with natural substances, Greek researchers tested a new type of bioactive packaging material. A nanohybrid of natural zeolite and the essential oil of thyme, thymol, was added to the widely used low-density polyethylene (LDPE) - the biopolymer version of which can also be used. Essential oils can have significant antioxidant and antimicrobial effects, but due to their volatile nature, their use in packaging materials is challenging. Zeolite is an easily accessible natural material, it improves the gas barrier properties of LDPE and is edible. In addition, it has excellent adsorbent properties as a nanocarrier, which offers a solution to the stability problems of essential oils. By forming the polymers with an essential oil-nanocarrier hybrid, the essential oil is released from the active packaging material in a controlled manner.

In the research, pure zeolite and its nanohybrid formed with thymol were mixed with low-density polyethylene at different concentrations, and the properties of the resulting film coating were investigated. The most optimal properties were achieved by adding 15% of thymol and zeolite to LDPE, so the effect of this coating on the shelf life of pork fillets was investigated.

According to the results, a promising active packaging film can be made from this packaging material combination, and food preservation and shelf life extension are possible with these natural, easily degradable materials.

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