51吃瓜

But there are still concerns that a toxic chemical, such as copper sulphate, might have caused the colour change.

Today when industrial-scale food adulteration occurs, such as the 85,000 tonnes of olives treated with copper sulphate that Italian police seized in February, we expect a systemic response.

Italian officers found 85 tonnes of olives painted with copper sulphate to enhance their green colour.

In Mexico in 2014, 40m litres of copper sulphate from a mine owned by Southern鈥檚 parent company leaked into a river.

Guardian critic Jonathan Jones described the copper sulphate chamber as 'one of the truly worthwhile and significant moments of modern British art'.