Diphenyl is an aromatic compound; from a chemical point of view, it consists of two benzene rings joined by a carbon-carbon bond (C-C). It is a substance that at room temperature appears as a colorless crystalline solid, insoluble in water but soluble in many organic solvents.
This preservative, of synthetic origin, is used in the food industry mainly for the anti-mold treatment of citrus peel, and for the material used for their packaging; at the same time, it allows the shelf-life of citrus fruits to be extended considerably. It is mainly used against fungi of the genus Penicillium, fungi that usually grow on these fruits.
When you read the words: "untreated citrus" it refers precisely to the absence of this Biphenyl. It is in fact recommended to consume this type of citrus fruit (especially if it is used, for any culinary preparation (cakes, limoncello, tea ... ) of the rind); if the "treated" ones are consumed, it is good practice to wash your hands thoroughly after having peeled them and before consuming the pulp. Despite all the precautions, a small part of the preservative can still penetrate inside the fruit, but this should not create any problems for the consumer.
The literature reports that workers employed in the field of citrus fruit shipments (by ship or truck), therefore exposed for long periods to this preservative, presented a certain sensitivity to diphenyl, complaining of allergic reactions, nausea, vomiting, eye irritation and to the nasal mucous membranes.
Apart from this, there are no significant side effects, also because diphenyl is a compound that is excreted by the kidneys in an unaltered form.
It was banned in Australia.
ADI DOSE: 0.05 mg / kg of body weight per day.