Nano film keeps fruits, veggies fresh for 2wks

Coimbatore: Scientists at the Tamil Nadu Agricultural University (TNAU) are developing a nano film that can extend the shelf life of cut fruits, vegetables and salads by two weeks. The film, made of plant fibres, can also replace plastic film wrappers.

Realising the need for a better post-harvest technology, TNAU has been focusing on ways to extend shelf life of harvested crop and prevent infestations.

“The film can be used to wrap bowls, trays and boxes of cut or uncut vegetables,” said Dr Subramanian, who is on the team developing the film. “The film has ultraviolet-resistance properties and prevents fruits and vegetables from respiring or breathing. Thus, it reduces the oxygen diffusion rate. UV exposure and oxygen diffusion lead to spoilage of fruits and vegetables, especially cut ones. By preventing both the occurrences, we extend the shelf life,” he said.

The nano film is made from plant fibres taken from the banana tree’s pseudo stem or agave americana (century plant).

In the case of banana, the sheath found on the outer portion of the stem is removed and sent to a fibre extraction unit. Such a unit is in Thondamuthur. The unit has a combing machine to press the sheath and scrape off pith. It results in a thin fibre that resembles cotton fibres.

“These white-colour fibres are then cut into 5cm and 10cm-long pieces and treated by dipping in an alkali solution, washing it off, then acid washing it. The treated fibres are then pulverized into a nano liquid,” said Subramanian.