Food Safety Focus (12th Issue, July 2007) – Food Incident Highlight

Copper Sulphate and Wrapping Leaves for Rice Dumplings

Last year, the media reported that industrial grade copper sulphate had been used to make the leaves for wrapping rice dumplings look greener in Mainland China. The Centre for Food Safety (CFS) subsequently conducted analysis of such leaves and found no evidence of such use in Hong Kong. Leaf samples were also tested this year and results indicated that they were not treated with the copper compound.

Excessive intake of copper can cause symptoms like diarrhoea, vomiting and jaundice. Copper sulphate is water soluble. Cooking in water could reduce its content. On the other hand, copper is an essential element and the body would need trace amount of this element to function normally. The trade is advised to purchase ingredients and materials from reliable suppliers and observe relevant regulations when using food additives.

Illustration: Rice dumplings and their ingredients