Scientists from NUS have developed a new eco-friendly, food packaging material that could double the shelf life of perishable food like bread.
It was developed using a natural biodegradable polymer called Chitosan, that is generally derived from the shells of shrimp and other crustaceans. It 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 anti-microbial and anti-fungal properties and in this case, the chitosan-based composite film was further fortified with grapefruit seed extract (GFSE). GFSE is an antioxidant and possesses strong antiseptic, germicidal, anti-bacterial, fungicidal and anti-viral properties. In short, desirable qualities in a food packaging material!
When packaged in the new material, fungal growth in bread sets in only at 10 days, compared to three days when using common food packaging materials like polyethylene. Hence, shelf life of bread doubled when packaged using the new material.
The film is made entirely of natural compounds, and can be made in a single day process in which chitosan and the extract of grapefruit seed are mixed, filtered, cast in petri dishes and then placed in an oven to dry. The final product is a thin transparent film.
“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.,” says Tan Yi Min, who co-led the research.
Since the grapefruit seed extract has anti-odour properties, they could be used to package strong-smelling foods like durian, explains Associate Professor Thian Eng San, from the NUS department of Mechanical Engineering.
Even though the raw materials needed may cause the new material to be 30 per cent costlier than the commonly used polyethylene, Prof Thian is confident that when the demand increases and it is produced on a large scale, the cost would be comparable. Moreover it is worthwhile to use the material to package more expensive food items like cheese and seafood such as salmon and prawns, he added.
Future studies involve biodegradability studies, studies that ensure the safety of the new material, as well as its effectiveness in packaging red meat and seafood.
The material is expected to hit the market in three to five years.