Sweet potatoes that turn green are safe: AVA

SINGAPORE - It is safe to consume sweet potatoes that turn green after being steamed, the Agri-Food and Veterinary Authority (AVA) has clarified.

In a statement on Monday, AVA said that they were aware of a message circulating online about sweet potatoes from Vietnam turning green after they were steamed, due to a chemical called "Agent Orange" in the soil.

Agent Orange is a herbicide and defoliant that had been used by the United States military as part of its herbicidal warfare program during the Vietnam War. The toxic herbicide caused many Vietnamese babies to be born with severe deformities, The Straits Times reported.

"We would like to assure the public that 'Agent Orange' is not known to cause sweet potatoes to turn green," AVA said.

Instead, the authority explained that sweet potatoes contains natural flavonoids and water-soluble pigments that can cause colour changes at different acidity levels or when exposed to air.

"The greenish colour can be due to a natural occurrence," AVA said, adding that they should not pose a food safety concern if cooked and stored properly.

The food safety agency also assured the public that food imports, including sweet potatoes, are regularly tested for chemical and other forms of contamination, such as heavy metals, pesticides and drug residues.

"Any food products that do not meet our requirements are not permitted for sale in Singapore."

seanyap@sph.com.sg