Turning Singapore's trash to treasure


The amount of food waste generated in Singapore has risen by about 20% over the past 10 years and is expected to increase with the growing population and economic activity. Yet only 18% of the total food waste was recycled in 2019, according to the NEA. But things are changing as more Singaporeans and local companies are becoming more environmentally conscious. The Sunday Times, in partnership with DBS Bank, gets to the bottom of upcycling, as Judith Tan and Vanessa Liu check out how four groups have added value to food waste

Food waste is one of the biggest waste streams in Singapore. While the authorities look at how to convert food waste into high value products that can give back to the economy, various groups have taken steps to upcycle food waste.

Big future in tiny insects

The humble black soldier fly, with its voracious appetite as larva, is being harnessed to eat discarded food and create rich nutrients for plants and animals.

This ubiquitous and harmless insect is being put to good use in the valorisation of food waste, which otherwise has negative value as it cannot be recycled, says co-founder and chief marketing officer of Insectta Chua Kai-Ning, 25.

"Food waste is a big problem in Singapore. In fact, we have one of the highest per capita rates of food waste in our region. The power of black soldier flies is their ability to upcycle food waste by eating it and converting it into valuable bio-materials," she adds.

Insectta is the first urban insect farm in Singapore to rear black soldier flies to process food waste and turn fly frass into organic food for plants and its larvae for animals.

The biotech company develops high-value, insect-derived biomaterials, such as chitosan, for both the pharmaceutical and cosmetic industries. Research by Insectta found that biochemicals extracted from the larvae can be used to produce chitosan.

"By harnessing these flies to transform organic matter into valuable resources, we have increased the value of the food waste - where it once was a negative-value product - to a positive-value product that is worth a few hundred dollars a gram," Ms Chua says.

The global chitosan market is valued at US$7 billion (S$9.34 billion) and is expected to expand by 25% between 2020 and 2030.

"Chitosan is a very potent wound-healing agent that can be used in bandages, sutures and anti-microbial coatings. Other than that, it can be used as a moisturiser for your face. Imagine - insect-derived cosmetics. Chitosan is also known to be a supplement used to lower cholesterol levels in the blood," she adds.

Insectta's research and development team is working with the Agency for Science, Technology and Research (A*Star) to yield multiple other high-value biomaterials from the flies.

Ms Chua Kai-Ning, chief marketing director of Insectta, with a handful of pupae inside the mating chamber that houses one million black soldier flies.ST PHOTO: LIM YAOHUI

Insectta is the first urban insect farm in Singapore to rear black soldier flies to process food waste and turn fly frass into organic food for plants and its larvae for animals.ST PHOTO: LIM YAOHUI

Pretty ugly food

Produce deemed too unsightly for sale, boxes containing excess vegetable, and baskets of over-ripe bananas and papaya are destined for the bins every day.

Co-founder of UglyFood Yeo Pei Shan, 25, found this not only wasteful but so sad that she had to do something about it.

Together with her friends, she set up her social initiative in 2016 to buy, at discounts, edible produce that would have been thrown away by wholesalers and retailers.

Ms Yeo started UglyFood while she was a student at the Singapore University of Technology and Design (SUTD).

"We use the blemished fruit to produce juices, soy milkshakes and popsicles. We also repurpose it by cutting it up for the acai bowls that we serve in our cafe."

Cutting up a pear, Ms Yeo shows how the blemishes on the skin are not on the flesh inside, which is white.

"The blemish is only skin deep and does not affect the pear, which is still safe to consume," she says.

"Surplus produce tends to be in better condition and have a higher shelf life, so we resell it as fresh produce both at our online and in the physical store," she adds.

The UglyFood cafe and store is located on the grounds of SUTD.

UglyFood also asks customers to donate used plastic boxes that are still in good condition and can be used to repack the loose fruit.

"We may not be plastic-free but we try to avoid single-use plastics," she says.

Ms Yeo Pei Shan, co-founder of UglyFood, with the rejected blemished fruit and vegetables which will be turned into juices, soy milkshakes and popsicles. The produce is also cut up for the acai bowls that the company serves at its cafe. ST PHOTO: LIM YAOHUI

UglyFood was started to buy, at discounts, edible produce that would have been thrown away by wholesalers and retailers. ST PHOTO: LIM YAOHUI

Digesting food waste in just 24 hours

Sitting in the bin centre of the JTC Aviation 2 @ Seletar Aerospace Park is a machine that is constantly hungry.

One of the smallest digesters in the stable of Westcom, a company that develops and produces equipment and products in food waste and other technology, it can transform 50kg of unconsumed food into 5kg of organic fertiliser in just 24 hours.

Westcom's largest digester can process more than 1,000kg of food waste in the same amount of time.

The company was set up in 2016 by entrepreneur David Tan to reduce and recycle food waste.

He imported 10 such machines from Japan, only to find that Japanese micro organisms could not effectively decompose local foods such as curry and hotpot meals, which are higher in oil and salt than Japanese food.

"This current technology is co-developed by A*Star and Westcom Singapore typically for local food waste. The micro organisms in the machine help to recycle food waste into odourless organic fertiliser," says Ms Ruby Fang, 29, vice-president of business development at Westcom Singapore.

The microbial treatment breaks down food waste, including bones, dough and even sugar cane safely and effectively, helping Westcom capture a slice of the global food waste processing market worth an estimated US$31.7 billion.

"We collect both cooked and uncooked food waste such as vegetables, eggshells and rice. The unique advantage of this technology is the low operating temperature. We are using about 30 deg C to recycle food waste, which can save up to 100% of energy," she adds.

A spokesman for JTC says the corporation has tried out several models of food waste digesters since 2016, and finally settled on the West Com version last year, which now produces fertiliser that JTC uses in its estates.

Other sites where Westcom's digesters are located include JTC Pandan Loop Industrial Estate, Jurong-Clementi Town Council, Khoo Teck Puat Hospital and One North.

The digesters use the food waste that comes from the canteens, cafes, hospital kitchen, and supermarket located in these areas.

Ms Ruby Fang, Westcom Solutions’ vice-president of business development, with a scoop of fertiliser composted from food waste, with Ms Joyce Teo, manager, facilities and estate management, at JTC standing near the food digester. ST PHOTO: LIM YAOHUI

The microbial treatment breaks down food waste, including bones, dough and even sugar cane safely and effectively. ST PHOTO: LIM YAOHUI

Growing veggies on fish poop

Nestled behind a coffeeshop in Tampines Industrial Park A is a community garden "powered" by a high-tech aquaponics system that converts fish waste from a tilapia pond into organic nutrients.

These nutrients are used to fatten organic vegetables such as xiao bai cai, kale, cherry tomatoes, winter melon, curry leaves and chilli padi.

"The idea of a community garden came about from a group of tenants who are passionate about gardening and keen to do something for the community, so I proposed one within the industrial estate," says Ms Catherine Koh, 51, president of the Tampines Small and Medium Enterprise Association.

Besides using recycled materials to build the 185.8 sq m garden, JTC also introduced the group to Metro Farm, a commercial organic smart farming firm which conducts research and development on smart aquaponics farming systems.

The company sponsored about $30,000 to build a custom vertical smart aquaponics farming system for the group, and trains volunteers on how to plant and harvest vegetables using it.

The system comprises a fish tank, a filter system and an area where the vegetables grow.

Director of Metro Farm Chris Toh, 39, says it is a close-loop, self-sustaining system.

"The waste in the water goes through the filter and is broken down by beneficial bacteria," he says.

"The vegetables then absorb the nutrients, purifying the water, which is pumped back to the fish."

The system also uses cameras, sensors and artificial intelligence to monitor and automate processes such as adjustments to the levels of the PH, temperature and nutrients.

Mr Toh explains that the red tilapia was chosen because "they have a higher rate of producing waste compared to the other breeds of fish".

"They are kept in the system for up to six months - from fingerling to table size of 600g - before we sell them to restaurants and zi char stalls," Mr Toh says.

Ms Koh says, "The community benefits from the vegetable harvest, which is sold for the upkeep of the system and to pay for fish food. A portion of the proceeds is donated to the needy."

The Tampines Industrial Park A community garden is "powered" by a high-tech aquaponics system. ST PHOTO: LIM YAOHUI

Ms Catherine Koh, president of the Tampines Small and Medium Enterprise Association, and Mr Chris Toh, director of Metro Farm, at the community garden that converts fish waste from a tank filled with tilapia into organic nutrients. ST PHOTO: LIM YAOHUI


Tips for festive celebrations
  • Prepare just enough: Make a shopping list, buy only what you need, and cater for between 10 and 15% fewer than the number of expected guests.

  • Think before you give: Pick food gifts that you know the recipient would enjoy, but avoid getting highly perishable items such as fruit and dairy products.

  • Go small: People usually prefer drinking and socialising to eating a heavy meal during this festive season, so provide smaller plates to reduce the amount of food left on them.

  • Freeze your leftovers in small portions: Divide leftovers into smaller portions and pack them into labelled airtight containers before freezing them. This makes foods freeze faster and reduces the need to thaw more than you need. You can also save some cash when you have them for lunch at work.

  • Give away excess food from your hamper: You are not going to need everything in the hamper you have received, so why not share - or better still, donate the excess non-perishables?


Where we are in this six-part series tracking food’s farm-to-fork journey

1. Overview

To understand the scale of the problem, 1,000 people were polled on what they know about food production, consumption and disposal here.

2. Farms

There is something fishy going on if, on a global scale, about one-third of all edible food, or about 1.3 billion tonnes, is wasted every year.

3. Wholesale

Volunteers regularly rescue vegetables and fruits discarded at the Pasir Panjang Wholesale Centre for aesthetic reasons or because of oversupply.

4. Retail

Four years ago, France became the first country to ban supermarkets from throwing away edible food. How far behind are Singapore stores?

5. Consumers

How much of the food in the family fridge ends up in the bin? Changing consumers' spending patterns can turn the tide on food waste.

6. Recycling

Dealing with the scraps after a meal is where you will find both scientists in lab coats and dumpster-diving food volunteers.

The Sunday Times and DBS are partnering in a six-part series to delve into Singapore’s growing food waste problem and its cost to families, businesses and the environment. #TowardsZeroFoodWaste

More on this topic: He turns unused and unsold bread into beer

Learn more about how you can continue your journey #TowardsZeroFoodWaste.

Find out more about DBS’ other partnerships and initiatives #TowardsZeroFoodWaste.

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