Oranges, lemons, grapefruit and limes have been cultivated since ancient times. The colour of citrus only develops in climates with cooler winters. Ripening is the changes that occurs after a fruit is mature. These changes involves starches converting to sugars and the acids decrease. Oranges were historically used for high content of vitamin C. British sailors were given citrus for long voyages to prevent scurvy, hence the nickname of "limey".