Fonterra milk 'tainted from shipping'

Fonterra researchers say a "musty" flavour detected in milk drinks containing calcium caseinate from New Zealand milk may have been caused by tainting by chemicals from wooden floors in shipping containers, or plastic liners used in shipping.

Scientists at the Fonterra Research Centre investigated samples of beverages and the calcium caseinate ingredient. They said in the in the International Dairy Journal that they had traced the intense musty/leathery smell to chemical tainting.

TBA, a chemical scientifically known as 2,4,6-tribromoanisole, was found at concentrations strong enough to smell in the drinks, and at even higher levels in the calcium caseinate samples. The scientists identified timber floors in shipping containers and slipsheets made from recycled plastics as two potential sources.

They did not identify any TBA in timber samples and recycled slipsheets but did find another chemical, TBP (2,4,6-tribromophenol) which can be easily converted to TBA by fungi found in the environment. Though materials that contained significant amounts of TBP still did not contain enough to fully account for the amount of tainting in the milk-based drinks, they said the levels found may have been affected by poor extraction of chemicals from the samples.

Fonterra now ships using slipsheets made from virgin plastic resins free of potential contaminants.

- NZPA