Food Safety Focus (108th Issue, July 2015) – Food Incident Highlight

The Colouring Matter Curcumin in Thai Durian

Last month, the Centre for Food Safety (CFS) detected the colouring matter curcumin and excessive residues of ethephon in durians imported from Thailand while following up on reports on the use of chemicals to accelerate ripening of Thai durians. The CFS has instructed the vendors concerned to stop the sale and remove from shelves the affected products. The CFS took follow-up samples from the vendors concerned and again detected curcumin in three durian samples . The CFS has informed the vendors that prosecution will be instituted should there be sufficient evidence. The Thai authority has also been informed for necessary follow-up actions.

Curcumin is a natural food colour extracted from the plant turmeric (Curcuma longa L.). Turmeric has a long history of use in food as a spice, mainly as an ingredient in curry powders and sauces, where curcumin is widely used to dye foods such as mustard, pickles, candy and soup. According to the Colouring Matter in Food Regulation (Cap 132H), curcumin is a permitted colouring matter which can be added to processed food. However, its use in meat, game, poultry, fish, fruit (except citrus fruit) or vegetable in a raw and unprocessed state are not allowed in Hong Kong.

Ethephon is a plant growth regulator that acts by generating ethylene during its decomposition, where ethylene can affect the growth of the plant. Ethephon is known to be used in pre-harvest ripening of fruits in certain countries. In Hong Kong, ethephon in food is regulated under the Pesticide Residues in Food Regulation (Cap 132CM). Although levels of ethephon residues exceeding the maximum residual limit prescribed by the law were detected in the durian samples, such levels will not cause adverse health effects under usual consumption. In general, removing the shells of durians before consumption can reduce the intake of the chemical.

The CFS will continue to follow up the incident and take appropriate actions to safeguard public health.