Raisin varieties depend on the type of grape used. Seedless varieties include the Sultana (also known as "Thompson ") and Flame. Raisins are typically sun-dried, but may also be "water-dipped," or dehydrated. "Golden raisins" are made from Sultanas, treated with Sulphur Dioxide (SO2) , and flame dried to give them their characteristic colour. A particular variety of seedless grape, the Black Corinth, is also Sun-Dried to produce Zante currants, mini raisins that are much darker in colour and have a tart, tangy flavour. Several varieties of raisins are produced in Asia and, in the West, are only available at ethnic speciality grocers. Green raisins are produced in Iran. Raisins have a variety of colours (green, black, blue, purple, yellow) and sizes.
Raisins are one of the richest sources of the mineral boron and provide concentrated amounts of polyphenolic phytonutrients.