The firm said two complaints were followed up and the products in question were recovered.
Parmalat’s investigation confirmed they had been contaminated with cleaning chemicals, making them unfit for consumption.
Production records have enabled the problem to be isolated to a production time window of less than five minutes affecting an estimated 300 packages in batch of over 125,000 units, said the firm.
However, all 200ml UHT PureJoy Apple Juice products with an expiry date of 14 and 15/12/2015 have been removed as a precaution from shelf in the majority of retail and wholesale stores.
Type of cleaning fluid
André Mahoney, Parmalat spokesman, said the cleaning fluid (a solution of Sodium hydroxide - also known as caustic) that is usually used to clean the line between production batches, entered the product feed during packing.
"At this stage it is not entirely clear how the machine came to dose a small amount of cleaning fluid into the process at that moment. All options are being investigated," he told FoodQualityNews.
"The electronic processor as well as operator actions and the combination are under scrutiny.
"All systems have been rechecked and additional controls have been implemented until we have the full picture.
"The frequency of product checks on the line has also been increased while the technical cause is examined."
The green-coloured cartons also have a production date of 14/12/14 and 15/12/14.
When asked why the incident has only come to light two months after the product date, Mahoney said the product has a 12 month shelf life.
"Because the incident was so small our normal quality control procedure which is best practice for this kind of operation could not detect the problem," he said.
"Our first indication was from a consumer who phoned our consumer help line. We were able to collect the product sample for testing and then the investigation into the line control records began.
"As soon as it was verified that the contamination could have affected more packs, Parmalat instituted a full public recall."
Mahoney said initial findings point towards a factory problem that led to the release of the contaminated packs.
“All the unsold affected products have already been recalled from our distribution system, as well as, where possible, from the stores to which it had been distributed.
“Our records indicate that the distribution for primary sale was most likely limited to the Western Cape, but we recognise that consumers or distributors could have taken the product into other areas.”
The recall only affects 200ml UHT PureJoy Apple Juice, no other products or code dates are involved.