With places like supermarkets and food retail outlets accounting for half of the food waste generated here, there was a need for tips on how such waste could be cut.

The National Environment Agency (NEA) decided a guidebook was timely. Not only does the book launched yesterday provide tips, it also explains the cost savings firms can reap as a result.

The step-by-step guide includes tips such as setting up proper storage conditions to prevent spoilage, and redistributing unsold food.

The NEA said non-domestic sources, which include supermarkets, food retail outlets and food manufacturers, account for about half of the food waste generated here, which has increased by about 40 per cent over the past 10 years.

Senior Minister of State for the Environment and Water Resources Amy Khor noted that some firms are already doing their part.

For instance, NTUC FairPrice sells blemished fruits and vegetables, and seafood and chilled meats that have been on display for a day, at marked-down prices. This has helped cut the amount of food waste it produces per sq m of retail space from 11.6kg in 2014 to 6.3kg last year.

Yesterday, Dr Khor lauded five shopping malls and a retail tenant for their waste-cutting efforts at the inaugural 3R Awards for Shopping Malls, held at Concorde Hotel Singapore. The award winners were malls 313@Somerset, Ikea Alexandra, Jem, Parkway Parade and The Shoppes at Marina Bay Sands, and beauty products retailer Kiehl's Singapore.

Ikea Singapore was the first retail mall chain operator here to stop providing disposable shopping bags, in 2013. In March last year, it also replaced disposable containers for takeaway meals with reusable ones.

As for Jem, it has installed eco-digesters that convert two tonnes of organic waste into non-potable water each day.

But more can still be done.

Last year, large shopping malls of over 50,000 sq ft of area that can be leased out collectively disposed of 225,000 tonnes of waste. While that was 7 per cent of the total waste disposed here that year, just less than 10 per cent was recycled.

"Clearly, shopping malls need to step up their waste minimisation efforts," Dr Khor said.

"I call on more operators to join this national effort towards becoming a Zero Waste Nation."