Ahead of the packaging
Compostable packaging has the potential option to combat waste from single-use plastic. However, not all compostable packaging is suitable for home composting. Researchers at Teagasc [Agriculture and Food Development Authority] are examining further avenues to more circular economy
Plastic has been the primary packaging material in the food industry for decades. In 2021, global plastic production reached 390.7 million metric tonnes, with approximately 141 million metric tonnes (about 36%) used in packaging. The food industry alone accounted for about 60 million metric tonnes of plastic use.
It is important to note that the life of plastic is virtually never-ending. It can take hundreds of years to degrade and, while certain plastics can be recycled, they can only be recycled a few times before their usability declines. In some instances, thermoplastics can be melted and reformed almost indefinitely. Ultimately, most plastics end up as waste in landfill or water bodies.
Breaking it down
Shifting to compostable packaging material developed from biodegradable polymers appears to be an intuitive alternative to plastic application, as these can be returned to the earth after use when handled appropriately. These packaging materials have gained a lot of attention, particularly in the food industries.
• ‘Biodegradable’ refers to a substance that can be degraded by microorganisms in the environment. Mulch films, thermoplastic starch (TPS), polylactic acid (PLA), polyhydroxyalkanoates (PHAs) and polybutylene adipate terephthalate (PBAT) are some of the examples of biodegradable polymers.
• 'Compostable' plastics are a subset of biodegradable plastics designed to break down under controlled environmental conditions into water, biomass and gases such as carbon dioxide and methane. Typical examples of compostable plastics are cellulose films, starch blends, PLA and PBAT.
Shivani Pathania, research officer at Teagasc’s Food Industry Development Department, explains: “Compostable plastics are designed to be either industrially- or home-compostable. Industrial composting takes place in controlled facilities specifically designed to efficiently break down organic waste materials. These composting facilities operate at a temperature range of 50-70°C under controlled humidity and aeration. During this process, microbes such as bacteria or fungi, along with their enzymes, carry out biodegradation of the material, converting it into CO2, water and biomass within six to 12 weeks.”
Home composting practices, however, vary widely, presenting more challenging conditions. It is carried out in a wide range of cooler temperatures, typically between 0-45°C, with variable humidity and oxygen levels.
“Therefore, compostable plastics which are designed to break down under industrial composting conditions may not break down under home composting conditions,” says Shivani.
Monjurul Hoque displays his pectin-based packaging films at the lab in Teagasc Ashtown.
Regarding the application of biodegradable packaging, Shivani cites a notion from the Ellen MacArthur Foundation: “Compostable packaging is popularly seen as an answer to plastic pollution, but, while it has a role to play in a circular economy, it is not a silver bullet. Any time a piece of packaging is used once – no matter how it is disposed of – it is single-use. Preventing waste in the first place should be the top priority.” Shivani adds that the compostable packaging system can be effective when a company ensures both supply and collection of packaging material after use. “This kind of collection service lessens contamination and leakage and guarantees its circulation at the highest value. For example, the service provider company BioPak reported restricting 15,000 tonnes of compostable packaging going into landfills in Australia and New Zealand in the last five years.”
Compostable plastics have the potential to replace about 20% of flexible plastic packaging. Also, the Bio-Based and Biodegradable Industries Association (BBIA) predicts that compostable packaging can take over almost 5-8% of total plastic packaging.
As Shivani points out, biodegradable packaging is starting to gain a foothold among some corporations in the sector: “UK-based compostable packaging company Vegware reported an increase in sales of 53% in 2019 and a further 43% in 2020. In Canada, KFC has promised to replace all its consumer-facing packaging with home compostable packaging by 2025. Recently, Frito-Lay’s has taken the initiative to test and develop compostable packaging solutions for name-brand products such as Lay’s, Cheetos and Doritos.”
A clear solution?
Of course, this research isn’t just happening at corporate level. Within Teagasc’s Food Industry Development Department, Shivani is leading the Sustainable Food Processing and Packaging research group. She is also a project partner on the University College Cork (UCC)-led, Department of Agriculture, Food and the Marine (DAFM)-funded PECTIPACK project.
This project aims to utilise 100% bio-based resources, mainly apple pomace, to develop biodegradable or compostable packaging materials for bread packaging applications. Under the aegis of PECTIPACK, Teagasc Walsh Scholar Monjurul Hoque has extracted pectin from apple pomace and developed packaging films at lab-scale.
He has also studied pectin formulations with marine-derived ingredients such as sodium alginate and carrageenan to develop highly functional films for food packaging applications. As Shivani tells us: “Monjurul is currently developing a scalable pilot-scale process for compounding and film development.” Such research, she adds, is made possible by using the state-of-the-art equipment available in the DAFM-funded Advanced Packaging Suite at Teagasc Ashtown. Packaging films developed by PECTIPACK, along with other packaging materials, were presented to approximately 100 visitors at Bord Bia’s [Irish Food Board] Bloom Festival 2023 in Phoenix Park, Dublin.
“The response to the survey has been outstanding, with most respondents showing significant interest in potential alternatives to traditional plastic packaging,” says Shivani. “Specifically, many respondents expressed a preference for pectin-based packaging material, which is developed from food waste, and appreciated its clarity and physical properties. Compostable plastics which are designed to break down under industrial composting conditions may not break down under home composting conditions”
This article first appeared in the autumn issue of TResearch, published by Teagasc.
Funding: The project is funded by the Department of Agriculture, Food and the Marine (Ireland).
Monjurul Hoque, Teagasc Walsh Scholar, Food Industry Development Department, Teagasc, Ashtown.
Shivani Pathania, research officer, Food Industry Development Department, Teagasc Ashtown.