A team of scientists from Institute of Nano Science and Technology, Mohali, an autonomous institute of the Department of Science and Technology, has developed a composite paper made of carbon (graphene oxide) loaded with preservatives that can be used as wrappers to help extend shelf life of fruits.
Unlike the present preservative dipping technology, where the preservatives are adsorbed by the fruit, causing chronic toxicity to the consumers; here the wrapper releases the preservative only when needed. The wrapper can be reused, which is not possible with the present technology.
The team led by Dr P S Vijayakumar had looked for an alternative to conventional preservation which relies on coating the preservative with the resin, wax, or edible polymer, which may cause chronic health problems.
“The high preservative-loaded graphene oxide, when cast into a paper used for fruit wrapping, ensures that the fruit is not loaded with toxic preservatives. But when the fruit over-ripens or gets infested by pathogens, the acidity increases by the secretion of acids, critic, and oxalic acids trigger the release of the preservatives for the preservation of the fruit.
“Otherwise, the preservative stays with the carbon wrapper. In the fruit dipping method, the preservative will be lost along with the fruit, whereas the wrapper can be re-used after the consumption of the fruit for the preservation of the next batch of fruits,” said a statement from the institute.
To develop this non-toxic and reusable wrapping paper, the team allowed carbon matrix to incubate with the preservative. After the incubation for 24 hour in room temperature, the resultant was washed several times to remove the extra preservatives. And finally, this carbon-preservative composite was cast into paper. This work has been published in the journal ‘ACS applied materials and interface’.
“Already waste-derived carbon materials are known to harbour huge amount of organic molecule loading, hence the preservative loaded carbon has been prepared and cast into paper for the fruit preservation. Increasing the capacity of carbon to hold organic molecules helped us to develop this product,” said Dr.Vijayakumar.
This novel product can benefit the farmers and food industry by extending the shelf life of fruits. Using this wrapper for the fruit will also ensure that the customer gets the fruits with healthy quality, as we have found improvement in the phenol content, the statement added.