SINGAPORE (BLOOMBERG) - With a tantalising array of satay chicken, wok-fried mud crab and chilled tiger prawns, the dinner buffet at Singapore's Grand Hyatt hotel typically sets diners back about US$70 (S$96).

But those on a tighter budget and with an eye on sustainability can fill a box for a 10th of that price.

Across Asia, tech start-ups are taking food otherwise destined for landfills and providing discounted meals through mobile phone apps.

About a third of food is lost or wasted every year globally, and the mountains of waste are estimated to cause 8 per cent to 10 per cent of greenhouse gas emissions such as methane, the United Nations says. The Asia-Pacific region is among the worst in the world when it come to food waste, accounting for more than half of food squandered globally.

"A common mantra that I have is that being sustainable should be attainable," said Mr Preston Wong, chief executive officer and co-founder of treatsure, which collaborates with chains, including the Accor group and Hyatt Hotels, and the Singapore Marriott Tang Plaza Hotel to allow app users to pick out and collect a "buffet-in-a-box" of food that would otherwise be thrown out.

"I think technology can bridge that gap," he said.

With more than 30,000 users, treatsure has saved an estimated 30 tonnes of food from going to waste since it launched in 2017, with users typically having to wait until the end of service before they can collect their food, according to Mr Wong.

Still, that is a far cry from the 817,000 tonnes of food waste in Singapore in 2021, a 23 per cent increase from the year prior. The authorities say Singapore's only landfill, Semakau Landfill, is expected to meet the country's solid waste disposal needs up to 2035 and beyond.

Hong Kong faces similar problems. It has already filled up 13 landfills, and about 3,300 tonnes of food waste a day were dumped in its remaining sites in 2020, according to the city's Environmental Protection Department.

"The space is very limited," said Ms Anne-Claire Beraud, country manager for Phenix by OnTheList, an app launched in the territory last year. "Everything is very dense, so there isn't a lot of space to treat all this waste."

The app allows users to pick up a "Mystery Basket" of food at stores, including Pret A Manger and local cake shop The Cakery, for a minimum 50 per cent discount.

So far, it has sold 25,000 baskets, with each equating to about 1kg of food saved from going to waste and 4.5kg of CO2 emissions avoided, the company said.

Phenix's original platform was launched in France in 2014 and expanded to four other European countries where it has saved 150 million meals. It collaborated with OnTheList, a flash-sale company, to bring the app to Asia.

The concept of food sustainability is still in its infancy in Asia, compared with North America and Europe where the authorities are cracking down. France has already banned supermarkets from throwing away unsold food, and Spain recently drafted legislation to tackle waste by fining companies. American states including California and New Jersey have laws to reduce the amount of food going to landfills.

This has boosted the popularity of apps like Too Good To Go, which was launched in Denmark in 2016 and now operates in 17 countries including the United States, Canada and Britain. It has provided more than 152 million meals through its so-called Magic Bags, which are sold at a discount by shops and restaurants at the end of the day with items that would otherwise have been thrown out.

In a region as culturally diverse as Asia, smaller local start-ups are getting a foothold catering to their home market.

Companies have to "match that region's culture and habits", said Mr Taichi Isaku, co-founder and chief product officer of CoCooking, which created the Tabete food rescue app in Japan. "It is an area that has to be nurtured in order to successfully introduce new technologies."

Tabete, released in 2018 in Japan, is a free app with a similar business model to Too Good To Go. It has rescued 384,000 meals, accumulated 525,000 users and partnered with 2,140 shops.

Ms Tess Kermode, director of international expansion at British-based Olio, agrees that companies need to "understand the culture and the people in a particular market".

The firm operates in 62 countries including India, Sri Lanka, Nepal, Thailand and the Philippines. The app is mostly community-based, with neighbours posting free food to be picked up from their homes. So-called Food Waste Heroes also collect surplus produce from businesses and bring it home to list.

Olio says the app has helped save almost 58 million portions of food worldwide. Its largest international market is Singapore, where it has more than 125,000 users and a formal partnership with foodpanda's online market. The firm has ambitions to expand but, like other apps, says a lack of awareness of food sustainability in Asia is currently a handbrake on growth.

Some apps, including treatsure and Tabete, are taking such matters into their own hands and trying to educate users with tips on reducing food waste and recipes on their social media pages.

"In North America and Europe, there has been some maturity in understanding such challenges and tackling them," said treatsure's Mr Wong. "But in Asia, this narrative has just begun."