Researchers from the National University of Singapore (NUS) developed an environmentally-friendly food packaging material that is free from chemical additives, by fortifying natural chitosan-based composite film with grapefruit seed extract (GFSE). This novel food packaging material can slow down fungal growth, doubling the shelf life of perishable foods.

Chitosan, a natural and biodegradable polymer derived from the shells of shrimp and other crustaceans, has immense potential for applications in food technology, owing to its biocompatibility, non-toxicity, short time biodegradability and excellent film-forming ability. Chitosan also has inherent antimicrobial and antifungal properties. GFSE, on the other hand, is an antioxidant and possesses strong antiseptic, germicidal, anti-bacterial, fungicidal and anti-viral properties.

Associate professor Eng San Thian and PhD student Yi Min Tan from the Department of Mechanical Engineering at NUS Faculty of Engineering spent three years perfecting the formulation to create a novel composite film that not only prevents the growth of fungi and bacteria, but also maintains mechanical strength and flexibility comparable to synthetic polyethylene film commonly used for food packaging. The composite film also effectively blocks ultraviolet light, hence slowing down the degradation of food products.

Laboratory experiments showed that the shelf life of samples packaged with chitosan-based GFSE composite films were two times longer than those packaged using synthetic packaging films.

“Increasing attention has been placed on the development of food packaging material with antimicrobial and anti-fungal properties in order to improve food safety, extend shelf life and to minimize 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. This novel food packaging material that we have developed has the potential to be a useful material in food technology,” says Thian.

“Extending the shelf life of food products also means reducing food waste, and as a result, reducing the rate of global food loss. This will bring about both environmental and economic benefits,” adds Tan.