24
February
2016
|
21:06
Asia/Singapore

Eco-friendly wrap promises fresher food

NUS researchers have developed a food wrap made from edible elements that doubles the shelf life of perishable food. The eco-friendly, biodegradable packaging, derived from crustacean shells, has been fortified with grapefruit seed extract (GFSE). The film, which is free of chemical additives, has immense potential in food technology due to its biocompatibility, non-toxicity, short-term biodegradability and excellent film-forming capability.

The NUS Mechanical Engineering team, comprising Associate Professor Thian Eng San and PhD student Ms Tan Yi Min, took three years to formulate the composite film. Their discovery was developed with food safety and environmental sustainability in mind.

“Increasing attention has been placed on the development of food packaging material with antimicrobial and antifungal properties, in order to improve food safety, extend shelf life and to minimise the use of chemical preservatives. Consumers are also demanding that packaging materials be formulated from natural materials that are environmentally friendly and biodegradable while improving food preservation,” said Assoc Prof Thian.

Chitosan — a natural polymer extracted from the exoskeletons of crabs, prawns and lobsters — has inherent antimicrobial and antifungal properties. GFSE, on the other hand, is an antioxidant and possesses strong antiseptic, germicidal, antibacterial, fungicidal and antiviral properties. 

When the chitosan-based wrap without GFSE was used on bread, fungi appeared after five days instead of three. Fungal growth was further delayed to 10 days if GFSE was incorporated into the chitosan film, the scientists discovered. The next-generation wrap also blocks out ultraviolet light, which degrades food due to oxidation and photochemical deterioration reactions.

chitosan 4

The process in which chitosan from crustacean shells, infused with grapefruit seed extract, was transformed into eco-friendly, biodegradable food packaging

The innovation not only prevents the growth of fungi and bacteria but it has mechanical strength and flexibility comparable to commercial food packaging. A food-grade plasticizer was added to the chitosan-based wrap to make it less brittle.

The fabrication process, which takes less than a day, involves mixing a solution of powdered chitosan and GFSE, which is filtered before a thin layer is syringed onto a petri dish. After being dried in an oven, the solution turns into a transparent film. Larger sample sizes may take a longer duration of time to produce, Yi Min added.

chitosan 1

The fabrication process takes less than a day

Presently, the researchers estimate that the film costs about 30 per cent more than normal food wrap to produce, but they anticipate that a commercialised product will be priced similarly to its plastic counterparts. If the team is unable to bring down the cost, they hope that the wrap’s green features will appeal to those who would buy premium produce such as red meat, seafood and dairy products.

The novel invention could reduce the sizable amount of plastic dedicated for packaging. Currently, about 18.5 million tonnes — the majority of plastic production — goes towards packaging, which generates about 60 per cent of plastic waste, according to the 2013 European Parliamentary Research Service.

Right now, the biodegradable wrap is about three to five years away from being sold on supermarket shelves. The product has garnered the support of the Agency for Science, Technology and Research’s Singapore Institute of Manufacturing and Technology, which will help link the researchers up with industry partners.

See press release and media coverage.