A new plant-based material can replace plastic food packaging for keeps

Plastic food packaging has two serious drawbacks: every year, it leads to the accumulation of millions of tons of plastic waste in our environment, and secondly, food items packed in petroleum-based plastic wrappers and containers are more susceptible to microbial contamination. However, now we may have an effective solution to these problems. A team of scientists has developed a biodegradable and antimicrobial food packaging solution that could finally put an end to the need for plastic-made food packaging items.  

What’s more surprising is that this eco-friendly food packaging comes in the form of a spray that creates a plant-based coating on your food items. This coating protects the food against microbial contamination and any damage that can occur during its journey from the farm to your home. Researchers from Rutgers University and Harvard developed the underlying technology that makes the food spray work.

One of the authors of the study and Associate Professor at Harvard School of Public Health, Philip Demokritou, said, “We knew we needed to get rid of the petroleum-based food packaging that is out there and replace it with something more sustainable, biodegradable, and nontoxic and we asked ourselves at the same time, ‘Can we design food packaging with a functionality to extend shelf life and reduce food waste while enhancing food safety?’’ 

The science behind antimicrobial food packaging  

A new plant-based material can replace plastic food packaging for keeps
Scientists applying the APF coating on Avocado. Source: Huibin Chang, Philip Demokritou and colleagues/Nature Food

While keeping the problems with plastic food packaging problem in mind, scientists developed a biopolymer using pullulan, a naturally occurring carbohydrate (polysaccharide) obtained from the fungus Aureobasidium pullulans and water (as solvent). Both these ingredients were processed through a focused rotary jet spinning system (FRJS) that turned the mix into antimicrobial pullulan fibers (APFs). 

Explaining the FRJS technology, Professor Demokritou told IE, “rotary jet spinning has been used extensively for biomedical applications and tissue engineering  and adopted here to be used for the synthesis of fiber-based coating and direct coating of food substrates.” In the next step, the researchers tested APFs against microbes like Aspergillus fumigatus and Escherichia coli that commonly infect fruits and vegetables.   

Interestingly, they observed a decline in the populations of these pathogens after the introduction of APFs. The researchers further deposited the antimicrobial fibers on avocados. They noticed that the APF coating prevented the growth of pathogens on the fruit and protected the same from spoilage and damage. Thus increasing the shelf life of avocados by about 50 percent.

Whereas plastic packets often release harmful chemicals into our food and take more than 400 years to biodegrade, the APF coating is a naturally derived biodegradable and non-toxic biopolymer that does not impact the quality of the edible it covers (a previous study also highlights that humans can digest pullulan). Moreover, according to the researchers, it can be easily washed off from a food item using water and takes only three days to completely decompose in the soil. 

Excited with these results, Demokritou wrote, “What we have come up with is a scalable technology, which enables us to turn biopolymers, which can be derived as part of a circular economy from food waste, into smart fibers that can wrap food directly. This is part of the new generation, ‘smart’ and ‘green’ food packaging.”

APFs might solve our plastic pollution problem to a great extent

It is well known how big the plastic waste problem is – there is more plastic in the oceans than fish and now in the form of microparticles (microplastics), plastic is getting into our bodies and causing various health issues. Moreover, plastic packaging is also one of the causes of microbial contamination and chemical toxicity in our edibles. The researchers claim that food pathogens give rise to over 600 million cases of food-borne illness annually. 

A report from the Waste and Resource Action Program (WRAP) in the UK reveals that plastic packaging also leads to higher amounts of food waste, decreasing the shelf life of fruits and vegetables. The report suggests that every year, 100,000 tonnes of edibles end up as waste, with plastic packaging weighing about 10,300 tonnes. 

The APFs have the potential to put a full stop to the havoc plastic food wraps wreaking out on our planet. Let’s hope this antimicrobial method soon becomes the new normal in food packaging. When asked about their plans to scale up the use of APFs, Professor Demokritou said, “We plan to identify investors for a start-up company on this (APF food packaging) and other food safety-related inventions.”

The study is published in the journal Nature Food.

Abstract:

Food waste and food safety motivate the need for improved food packaging solutions. However, current films/coatings addressing these issues are often limited by inefficient release dynamics that require large quantities of active ingredients. Here we developed antimicrobial pullulan fibre (APF)-based packaging that is biodegradable and capable of wrapping food substrates, increasing their longevity and enhancing their safety. APFs were spun using a high-throughput system, termed focused rotary jet spinning, with water as the only solvent, allowing the incorporation of naturally derived antimicrobial agents. Using avocados as a representative example, we demonstrate that APF-coated samples had their shelf life extended by inhibited proliferation of natural microflora, and lost less weight than uncoated control samples. This work offers a promising technique to produce scalable, low-cost and environmentally friendly biodegradable antimicrobial packaging systems.

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