Could Asia’s passion for tofu help solve the plastic crisis?

A staple in the Asian diet, soybeans have been used to make tofu, miso soup and soy milk for hundreds of years. But now, the popular legumes are also being turned into an alternative to plastic wrap.

William Chen, a professor of food science and technology at Singapore’s Nanyang Technological University, invented the biodegradable food wrap. It’s made of cellulose, extracted from the waste generated by soybean product manufacturers.

Soybeans are crushed to squeeze out juice that’s used to make bean curd and soy milk, explains Chen. What’s left is a porridgey residue, which is usually dumped. Chen takes the mushy leftovers and puts them through a fermentation process. Microbes gobble up the nutrients, leaving behind cellulose, a form of fiber.

Tofu by-products: a viable plastic alternative?

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Cellulose-based plastic wraps have been on the market for a few years but Chen says that most are made from wood or corn, cultivated for that purpose. By contrast, his wrap is made from a waste product – so it doesn’t compete with edible crops for land and is more sustainable.

Chen’s technology could help to solve two problems at once: cutting plastic production and reducing the amount of food waste deposited in landfill. “In Singapore, the amount of food waste we generate every year can fill up 15,000 Olympic-sized swimming pools,” he says, adding that because soy products are so popular in Singapore, 30 tons of soybean residue is produced there every day.

William Chen, professor of food science and technology at Singapore's Nanyang Technological University, is developing biodegradable plastics using soybean waste.

PHOTO: Nanyang Technological University

F&N, a soy-based drinks producer, has partnered with Chen’s lab and provides the residue, straight from the factory. The company is conducting a feasibility study to assess whether the food wrap could compete, commercially, with conventional products, says Chen.

Scalability is sometimes an issue with bioplastics, which are typically more expensive to produce than their petrochemical counterparts. The soy-based wrap costs “almost nothing” to make in the lab, says Chen, because the raw materials are free of charge. Commercial scale production would involve additional expenses, such as storage and quality control, however “we have not calculated those costs yet,” says Chen.

Soybeans are not the only natural product he’s turning into bioplastic. Chen has also developed a method to transform the cellulose-rich husks of the durian – a notoriously smelly tropical fruit – into plastic wrap. Despite the fruit’s controversial odor, Singaporeans consume 12 million durians a year, he says, so there is an ample supply of discarded husks.

Photos: Be wary of these everyday items

Many brands of hand soap contain the controversial chemical triclosan, which is linked to serious health conditions and causes cancer in mice. The chemical is also extremely resilient and can survive water treatment, enabling it to reach the ocean and destroy bacteria that form the base of the food chain. In September 2016, the Food and Drug Administration issued a rule banning antibacterial soaps and body washes containing triclosan or 18 other active ingredients from being marketed, because the ingredients were not proved to be safe and effective for long-term daily use.

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Photos: Be wary of these everyday items

Coffee pods deliver gourmet-quality coffee with the advantages of low cost and high convenience. Little wonder that the pods achieved rapid popularity; 29% of US households own a coffee pod machine, according to the National Coffee Association. But there are high costs elsewhere, as the plastic and aluminum pods are fiendishly difficult to recycle and billions end up in landfill each year. Former Nespresso CEO Jean-Paul Gaillard has stated that they are contributing to an environmental disaster, although the company claims to be addressing recycling and sustainability concerns. In 2016, the German city of Hamburg banned the use of coffee pods in public buildings, and the conflict seems guaranteed to escalate.

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Many toothpaste brands have been discovered to contain plastic microbeads, a leading contributor to the 8 million tons of plastic that enters the ocean each year, with devastating consequences for wildlife and the marine environment. Microbeads do not biodegrade and are too small to be caught in clean-up exercises, and they attract toxic chemicals as they travel. The microscopic menaces are also found in various shower gel and cream products, but perhaps not for much longer. Microbeads have been banned in the US, Canada and the UK, and countries across Europe are looking to follow suit.

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Photos: Be wary of these everyday items

Disposable chopsticks are stripping Asian forests bare. Almost 4 million trees are sacrificed to produce 57 billion pairs of disposable chopsticks each year, according to Greenpeace, and they are treated with chemicals that can cause respiratory disorders. There are also human rights issues, as chopsticks have reportedly been produced in labor camps, according to Amnesty International.

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Wet wipes are increasingly popular for use on skin or household surfaces, which is causing problems further down the line. Although labeled as "flushable," they contain plastic and don't break down easily like toilet paper. When disposed via the toilet, the non-biodegradable products cause blockages and "fatbergs" in sewers and wash up in huge volumes on beaches.

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Photos: Be wary of these everyday items

Plastic bags are one of the most damaging sources of everyday pollution. By some estimates, 1 trillion non-biodegradable plastic bags are disposed of each year, breaking down in waterways, clogging landfill sites and releasing toxic chemicals when burned. Initiatives to control plastic bags such as supermarkets charging for them are beginning to make a dent in the epidemic.

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Batteries typically contain a toxic cocktail of harmful elements, including cadmium, lead and mercury, that leak into soil and waterways, causing dangerous pollution. If batteries are incinerated, the metals become airborne and increase health risks. Recycling facilities for disposable batteries are increasingly common, but it's better to choose rechargeable alternatives where possible.

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Photos: Be wary of these everyday items

Traditional paper tea bags contain elements of plastic, but manufacturers are increasingly using new formulas based on nylon or polyethylene terephthalate (PET). Plastic tea bags supposedly offer a higher-quality brew, but they are resistant to composting, and there are fears that they release dangerous toxins.

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There is a growing evidence that playing it safe with birth control pills can play havoc with the hormones of fish populations. Studies have found that certain species were unable to reproduce after exposure to endocrine disruptors, threatening the population and wider ecosystem. Don't stop using the pills, but if you need to dispose of them, don't pour them down the drain.

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Polystyrene-based material is almost unavoidable in disposable packaging, but it's also non-biodegradable and difficult to recycle, going on to blight landscapes and poison small animals after use. Several cities across the US have banned it. Fortunately, ingenious alternatives are becoming available.

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Photos: Be wary of these everyday items

A cheap shave has a high cost through the carbon-intensive production of steel and plastic, and the high water use they are associated with. An estimated 2 billion razors are discarded each year in the US alone. Electric and straight razors will give you peace of mind to accompany your smooth glow.

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Biodegradability is another potential hurdle. Some bioplastics breakdown fully only when exposed to temperatures exceeding 50 degrees Celsius for prolonged periods. Concerns have been raised that if bioplastics are not disposed of in special facilities, they could add to the plastic pollution problem.

However, Chen says his soybean-based plastic wrap is digested by microbes and disappears completely within a month when disposed of in general household waste, without the need for heat.

Chen is not the only inventor seeking to replace plastic with biodegradable alternatives. Other innovative products include MarinaTex, a plastic film made from fish waste that’s suited to making sandwich bags; sequins made from plant matter; and drinks containers and sachets made from seaweed.

Chen says he hopes neighboring soy-loving countries will be inspired by Singapore and adopt his innovation: “My dream is that our technology, which is cheap and simple to implement, will cut plastic and food waste and create a cleaner environment.”