Researchers from the National University of Singapore (NUS) have 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 food packaging material can slow down fungal growth, doubling the shelf-life of perishable food, such as bread.
Chitosan, a natural and biodegradable polymer derived from the shells of shrimp and other crustaceans, has 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 antioxidant and possesses strong antiseptic, germicidal, anti-bacterial, fungicidal, and anti-viral properties.
The researchers spent three years perfecting the formulation to create a novel composite film that not only prevents the growth of fungi and bacteria, but has mechanical strength and flexibility that are 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 as a result of oxidation and photochemical deterioration reactions.
Laboratory experiments showed that the shelf life of bread samples packaged with chitosan-based GFSE composite films was two times longer than those packaged using synthetic packaging films.
The researchers will be conducting further studies to improve on this technology. They will look into the degradability of chitosan-based GFSE films, as well as carry out an accelerated shelf-life study to examine the extent of microbial growth and quality changes during storage of various food products.
