SINGAPORE - The blue substance found on some vegetables bought from some NTUC FairPrice outlets is residual remnants of undissolved fungicide, said the supermarket chain in response to queries from The Straits Times.
At least three consumers had shared photos of the affected vegetables online, citing concerns over food safety.
In the photos, the blue substance appears either as solid pellets or liquid stains.
In a statement sent to The Straits Times on Wednesday (Sept 27) night, NTUC FairPrice said food safety is of "paramount concern" and that its food products comply with stringent regulatory requirements and have been approved for sale by the authorities.
However, it acknowledged that "better care should have been taken to process the vegetables before they were packed".
"We have made known our concerns with the supplier in question and have taken the necessary actions to ensure this does not recur."
The Agri-Food and Veterinary Authority has said that it is investigating and will be taking samples from the vegetables for food safety tests.
NTUC FairPrice said customers who bought fresh produce from the supermarket chain and find the quality unsatisfactory can return the product to the same store with their receipt before the stated expiry date for a full refund or exchange.
"While efforts are in place to ensure that produce is free from residue, it is good practice for consumers to wash all produce prior to consumption," it added.