IIT Guwahati researchers develop edible film to increase shelf life of fruits and veggies

Are you fed up with fruits and veggies rotting fast? And concerned about food wastage due to this? Then here's some good news! Researchers from the Indian Institute of Technology Guwahati (IIT-G) might just have come up with a solution to this worldwide problem. They have developed an edible and biodegradable coating to extend the shelf-life of fruits and vegetables.

The results of their research have been published in noted journals, including the Royal Society of Chemistry Advances, the Food Packaging and Shelf Life and the American Chemical Society's Food Science and Technology. The researchers believe that their development could help the country meet the Sustainable Development Goal (SDG) target 12.3, as reported by PTI.

SDG 12.3 aims at reducing food loss in the production and supply chains, including post-harvest losses. "According to the Indian Council of Agricultural Research, between 4.6 and 15.9 per cent of fruits and vegetables go waste post-harvest, partly due to poor storage conditions," said Vimal Katiyar, Professor, Department of Chemical Engineering, IIT Guwahati.

"In fact, post-harvest loss in certain produce like potato, onion and tomato, which could be as high as 19 per cent, which results in high prices for this highly consumed commodity," he added. The research team used a mix of a micro-algae extract and polysaccharides to produce protective, edible films for coating on vegetables and fruits, he informed.

"It is also used as a source of algal oil, which is used as a non-animal source of omega-3 fatty acid, and is being considered as a source of biofuel. After the oil is extracted, the residue is usually discarded. The researchers used extracts from this residue in formulating their film, in combination with chitosan," the professor said.

"Chitosan, a carbohydrate, also has antimicrobial and antifungal properties and can be made into edible film. The properties of films with varying algal extract contents were analysed and compared with controls," he added.

According to IIT-G officials, this coating material, which will prevent wastage, was tested on vegetables such as potato, tomato, green chilli, strawberries, Khasi Mandarin variety of orange, apples, pineapples and kiwi, and was found to keep these vegetables and fruits fresh for nearly two months.

Professor Katiyar explained the reason was that the fabricated edible films displayed superior antioxidant activity, total phenolic content, water vapour barrier property, thermal stability and mechanical strength. They also had excellent UV-Vis light-blocking properties, he told.

He also said that multiple other customised edible coating formulations could be developed to enhance the shelf-life of produces based on the requirement. "We also tested the biosafety of these coatings by treating BHK-21 cells with these coating materials," he informed, as per PTI.

"BHK-21 cells are derived from the kidneys of baby hamsters and are used for studying the toxicity effects of various materials. Their tests showed that these coating materials were nontoxic and could be safely used as edible food packaging materials. The newly-developed coatings can be mass-produced and are unique," he said.

"They are very stable to light, heat and temperature up to 40 degrees Celsius, edible and can be safely eaten as part of the product formulation and do not add unfavourable properties to it. They retain the texture, colour, appearance, flavour, nutritional value and microbial safety of the fruit or vegetable that has been coated, thereby enhancing their shelf life to several weeks to months," the professor stated.