Old olives from previous years' harvests which had lost their colour were 'recycled' with a coat of copper sulphate to give them an intense and uniform green colour.

Copper sulphate is allowed to be used in agriculture, but the samples seized in Italy contained more than twice the legal limit. Vegetable oils are an easy target Overall, Operation Opson V found ...

Nearly 94,000 tons of green olives have been seized by Italian police after it was discovered that copper sulphate was used to enhance their color, the British daily The Guardian reported.

The period of unsightliness can now be eliminated by subjecting the copper to electrolytic corrosion under controlled conditions; after 15 minutes an insoluble patina of good green colour is ...

Italian police have seized 85,000 tonnes of green olives treated with copper sulphate to brighten their colour, and thousands of tonnes of foreign olive oil being passed off as "Made in Italy".