by Carl Saxton
High levels of antimony found in fruit juices causes concern for health, say European scientists.
Antimony has no known biological function and the effects of long term human exposure are unknown. Antimony trioxide, a suspected carcinogen, is used as a catalyst in polyethylene terephthalate (PET) production which is used to package foodstuffs. Previous studies concerning antimony leaching into bottled water have investigated the effects of variable physical conditions such as time, temperature and sunlight. But Claus Hansen and colleagues at the University of Copenhagen, Denmark, speculated that as citric acid is known to be an efficient antimony extractant, acidic fruit drinks could leach more antimony than water from PET.
Hansen measured the antimony concentration in 42 containers of red fruit juices including blackcurrant, strawberry, raspberry, sour cherry, mint and synthetic caramel, using inductively-coupled plasma mass spectrometry (ICP-MS), and found antimony concentrations up to 17-fold higher than previous reports. The highest antimony concentrations, found in one particular brand of blackcurrant juice, were above the recommended EU levels for drinking water (5 micrograms per litre).
Even though the levels of antimony were high in the juices, the team were unable to identify the source of the contamination, which could arise from the packaging material quality, the drinks production process or from sugar-aided extraction, explains Hansen.
'The antimony concentrations in the products tested exceed the antimony limit in EU drinking water but no antimony limits exist for foodstuffs so no legislation has been broken' says Hansen. 'However, we cannot be sure that the antimony levels found are harmless,' he adds.
Agneta Oskarsson, an expert in food toxicology, at the Swedish University of Agricultural Sciences, Uppsala comments, '[This work] emphasizes the need to follow up exposure and health risks due to increased usage of such elements as knowledge on antimony exposure and toxicity is scarce, therefore more data on the antimony speciation is required.'
The team are now attempting to detect the source of the contamination and to test whether sugar acts as an extracting agent for antimony in PET materials which could lead to restrictions in the use of PET for packaging sugar-rich foodstuffs.