Photos of olive oil: genuine and adulterated olive oils.

Photos of olive oil:  genuine and adulterated olive oils.

The green colour in the adulterated olive is due to the additive called Copper chlorophyll 銅葉綠素.

Copper chlorophyll is a coloring additive banned from food products for possibly causing liver problems.

Photo source:

(journal of agricultural and food chemistry, USA)

http://pubs.acs.org/doi/abs/10.1021/jf902084d