Longer shelf life for food? It's all a part of this package

Examples of food stored in the packaging developed by the scientists and Dou Yee Enterprises, next to the same products in their normal packaging. Dou Yee Enterprises vice-president Alex Tan with food stored in the packaging, and senior scientist Li
Dou Yee Enterprises vice-president Alex Tan with food stored in the packaging, and senior scientist Li Xu, who is holding a roll of the film used for the packaging. They are working together to put the product on the market.ST PHOTOS: MARK CHEONG
Examples of food stored in the packaging developed by the scientists and Dou Yee Enterprises, next to the same products in their normal packaging. Dou Yee Enterprises vice-president Alex Tan with food stored in the packaging, and senior scientist Li
Examples of food stored in the packaging developed by the scientists and Dou Yee Enterprises, next to the same products in their normal packaging. ST PHOTOS: MARK CHEONG

New material by A*Star scientists lets less oxygen enter, allowing expiry date to be extended by at least 50%

Singapore scientists have developed a packaging material that could help reduce the growing amount of food waste produced in the country.

Its ability to prevent oxygen from entering the packaging can extend the shelf life of food by at least 50 per cent. Oxygen, among other things, is needed for micro-organisms such as mould to grow, and these are the nasty bugs that cause food to turn bad.

Creators of the material are working with home-grown manufacturing company Dou Yee Enterprises to produce it for the retail market. They are starting small, with a few hundred thousand pieces at a time.

The team of five scientists is led by Dr Li Xu, from the Institute of Materials Research and Engineering at the Agency for Science, Technology and Research.

Dr Li explained that the innovation is a three-layer laminated plastic film with a clay-polymer composite inserted between two plastic layers. The plastic layers are made of common plastic films like polyethylene terephthalate, widely used in food packaging, while the clay is naturally sourced, said Dr Li.

"The special structure of the material creates a highly efficient barrier that prevents gas molecules like oxygen from coming into contact with the contents of the package," he added. The material has been tested more than 20 times on food such as grains, cakes and bread.

It could block 150 times more oxygen than normal plastic packaging, said Dou Yee Enterprises vice-president Alex Tan.

For cakes that expire in seven days, for instance, tests show the shelf life was extended to at least nine days without using any oxygen absorbers.

The new material is more effective because only 0.5 cubic cm of oxygen per sq m passes through it daily, compared to normal plastic's 77 cubic cm per sq m each day, he added.

"As the product is made of natural clay inserted in between two similar plastics, it is possible to make this film recyclable," Mr Tan said.

"Farmers put in a lot of effort to grow food and for traders or supermarkets to waste it is very sad," he added.

The amount of food waste generated in Singapore has risen by almost 50 per cent, from 542,700 tonnes in 2006 to 785,500 in 2015.

A survey commissioned in 2014 by the National Environment Agency and Agri-Food and Veterinary Authority found that the top three reasons for throwing food away are: "it is past the expiry date"; "food is mouldy"; and "it looked, smelled or tasted bad".

However, Mr Eugene Tay, executive director of environmental group Zero Waste SG, noted that the longer shelf life could result in a "rebound effect" if a person, assured that the food can last longer, forgets to finish it before the expiry date. "Besides increasing shelf life, clearer and standard date labels would help reduce food waste," he said.

Dr Li and his team are now researching "oxygen scavenging" technologies that can help absorb the remaining oxygen in food packaging.

"It could come in the form of nano-composite materials, or regular bead-size particles put in a sachet that is placed inside the packaging along with the food," said Dr Li.

A version of this article appeared in the print edition of The Straits Times on March 03, 2017, with the headline 'Longer shelf life for food? It's all a part of this package'. Print Edition | Subscribe