Food packaging

Plastic food packaging gets a bad rap, but does it still deserve it?

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Social media can be a powerful force for positive change, especially when it comes to environmental issues. A seemingly perfect example is the drive to stem the tide of single-use plastic, especially when it comes to food packaging.

Huge campaigns – including organized groups going down to supermarkets to remove and empty all packaging from their purchases and leave them at the checkout in what’s called a “plastic attack” – led to some pretty dramatic changes, both in business and government. But it is possible that these kinds of well-meaning gestures, based on simple messages and adapted to social media, could have unintended consequences.

The less geek among us might ignore the fact that fruits and vegetables are still living plants, constantly interacting with the world around them in complex ways, some of which degrade the product. Under supermarket light bars, they continue to photosynthesize, make new compounds, break down others, and even emit growth regulators into the air that affect the behavior of neighboring crops on the shelves. surrounding them.

Understanding these incredibly sophisticated interactions and how to control them spurred the creation of a branch of study called postharvest technology. Over the past half-century or so, this has led to a series of ingenious inventions, including packaging, which have dramatically extended the shelf life of crops. Waste has been reduced and nutritional quality and flavor improved.

Take, for example, a study published in 2011 showing that shrink-wrapped cucumbers lost significantly less water on a typical farm-to-fork journey than the unpackaged equivalent, extending shelf life to ‘to 60%.

The abandonment of this packaging would therefore have a significant impact on the food because, most of the time, the harvest would die out before being eaten.

The benefits of plastic packaging do not end with shelf life, but can also retain the nutritional value of crops. Broccoli is a good example. This can lose up to 80 percent of its glucosinolates, a group of phytochemicals believed to be responsible for some of the major health benefits of the crop, when loose on supermarket shelves, compared to the shrink-wrapped version in the cooler. Such effects have been found across a wide range of cultures, which is one of the main reasons retailers are spending more to use packaging in the first place.

“If food waste were a country, it would come third after China and the United States in terms of carbon emissions”

It can be easy to assume that biodegradable food waste does not have the same environmental impact as plastic waste which can linger for hundreds or even thousands of years. However, evaluating this is not that simple. Although fruit and vegetable waste quickly breaks down into compounds, many of which are benign, the environmental cost of producing these foods in the first place can be surprisingly high.

Food and Agriculture Organization of the United Nations estimates that a third of all food is wasted, and so many resources are devoted to its production that, if food waste were a country, it would come third after China and the United States in terms of carbon emissions. This equates to 87 percent of all road transport emissions. Based on these stats, grow that wasted food requires nearly 13% of the planet’s agricultural land and, if all waste was avoided, it would be enough to feed 2 billion people.

Granted, comparing metrics like carbon emissions and land use with plastic pollution falls into apple and orange territory (excuse the pun), but given the importance of the problem, some research has tried to calculate the net effect.

A recent study published prior to formal peer review, from the Swiss Federal Laboratories for Materials Science and Technology, looked into cucumber production and found that plastic packaging was only responsible for 1% of the food’s total environmental impact. the net environmental impact of 93 plastic packaging. The study concluded that, in the context of reducing food waste, plastic was beneficial: by extending shelf life, the net environmental benefit of packaging cucumbers was 4.9 times greater than not disturbing. . This shows that packaging is a complex and confusing issue.

Given the obvious benefits of using certain plastic packaging on certain crops, I wonder if we should ditch the idea of ​​blanket bans and instead consider which types are actually beneficial for shelf life, and therefore for the planet, and which ones are just there for marketing or presentation. And what about a third approach of switching to alternative, more recyclable or perhaps even biodegradable packaging, for cases where plastic plays a useful role, rather than completely abandoning it – even though such an approach does not get as many shares on social media.

Jacques’ week

What i read
Stuck on the couch for three weeks with an intense case of covid-19, I read very little, alas

What i watch
I used the film Shang Chi and the legend of the 10 rings. Botanical mistakes are enough to infuriate even a mild-mannered plant scientist

What i am working on
New TV series on the future of farming will end next January on BBC World News

  • Next week: Chanda Prescod-Weinstein

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