Indian scientists have developed a graphene oxide composite paper, loaded with preservatives, that can be used as wrappers to help extend the shelf-life of fruits, stated the Department of Science and Technology.

In the currently used technology, preservatives are adsorbed by the fruit, causing chronic toxicity. In the team's new paper, the wrapper releases the preservative only when needed. The wrapper can also be reused, which is not possible with the present technology.

Fruits are highly perishable. Hence 50% of fruits produced are wasted, causing huge losses. Conventional preservation relies on coating the preservative with the resin, wax, or edible polymer, which may cause chronic health problems.

To address this problem, a team of researchers led by P S Vijayakumar from the Institute of Nano Science and Technology, Mohali, an autonomous body under the DST, looked for an alternative that could be generated from waste and would not lead to adsorption of preservatives in the fruit.

The activated graphene oxide-loaded molecules are loaded with preservatives. This high preservative-loaded graphene oxide, when cast into a paper used for fruit wrapping, ensures that the fruit is not loaded with toxic preservatives.

When the fruit over-ripens or gets infested by pathogens, the acidity increases by the secretion of acids. Oxalic acids trigger the release of preservatives to protect the fruit from decay. Otherwise, the preservative stays with the carbon wrapper.



To develop this non-toxic and reusable wrapping paper, the team allowed the carbon matrix to incubate with the preservative. After the incubation for 24 hours at room temperature, the resultant was washed several times to remove extra preservatives.

Finally, this carbon-preservative composite was cast into paper.

"Already waste-derived carbon materials are known to harbour huge amounts of organic molecule loading. Hence, the preservative loaded carbon has been prepared and cast into paper for fruit preservation. Increasing the capacity of carbon to hold organic molecules helped us to develop this product," said Vijayakumar.

This novel product can benefit the farmers and the food industry by extending the shelf-life of fruits. Using this wrapper for the fruit will also ensure that the customer gets healthy quality fruits as we have found improvement in the phenol content, he said.

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