Natural wax produced by fruits and some commercial types are edible, but industrial-grade coatings are illegal
Reader Valencia Seah wrote in to askST after buying some apples.
"As I could see a whitish layer on the skin, I used a knife to scrape it off. I had to go through a few rounds and there were quite a lot of white shavings," she said.
"I did a bit of reading and found that apples naturally produce wax, just like plums. But some producers do add wax to apples too. I would like to check if it is safe for daily consumption and are consumers urged to scrape off the layer of wax before eating?"
Food correspondent Eunice Quek found the answer.
Dr Wu Yuan Sheng, deputy director (pesticide residues section) of the veterinary public health lab chemistry department under the Agri-Food and Veterinary Authority (AVA), explains that many plants, including fruits and vegetables consumed daily, such as apples, plums and pears, as well as citrus fruits like oranges and lemons, have a natural protective layer of wax on their surfaces.
He says: "These natural waxes are not harmful to human beings."
To minimise moisture loss and extend shelf lives during shipment and storage, some fruits may be treated with a layer of commercial wax, he adds.
Several types of commercial wax can be used for coating fruits, and they may be food-grade wax or made of natural products.
He says: "The use of industrial-grade wax for coating fruits is illegal as it may contain harmful impurities. The AVA, so far, has not found any fruit product coated with illegal substances."
For consumers who do not want to ingest the fruit wax, simply peel the fruits prior to consumption.
A version of this article appeared in the print edition of The Straits Times on October 14, 2017, with the headline 'Is the layer of wax on some fruits harmful?'. Print Edition | Subscribe
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