Lemon

Lemons were a citrus fruit on Earth.

The planet Oroobia had the general scent of lemons when the Tenth Doctor and Donna Noble visited. (PROSE: The Doctor Trap)

In drinks
Whilst in 1926, Donna Noble consumed a "sidecar" (Cognac, orange liqueur and lemon juice). (TV: The Unicorn and the Wasp)

The Third Doctor preferred lime to lemon in his Bombay Sapphire Gin when he drank with Iris Wildthyme. (PROSE: Verdigris)

Skullions prefered citrus juices such as lemon and orange as water "burned" them. (TV: The Man Who Never Was)