Saffron (trade) by far the world's most important producer: in 2005 it grossed some of dry threads, or 93.7 percent of the year's global total mass; much of the Iranian crop was bound for export. Northeasterly Khorasan Province, which in 2004 was divided in three, grows 95 percent of Iranian saffron: the hinterlands of Birjand, Ghayen, Ferdows in South Khorasan Province, along with areas abutting Gonabad and Torbat-e Heydarieh in Razavi Khorasan Province, are its key cropping areas. During 2004, Iran was not a member of the World Trade Organization. and still until November 2009, Iran was again not a member of
Saffron action, splits picrocrocin to yield D–glucose and a free safranal molecule. Safranal, a volatile oil, gives saffron much of its distinctive aroma. Safranal is less bitter than picrocrocin and may comprise up to 70% of dry saffron's volatile fraction in some samples. A second molecule underlying saffron's aroma is 2-hydroxy-4,4,6-trimethyl-2,5-cyclohexadien-1-one, which produces a scent described as saffron, dried hay-like. Chemists find this is the most powerful contributor to saffron's fragrance, despite its presence in a lesser quantity than safranal. Dry saffron is highly sensitive to fluctuating pH levels, and rapidly breaks down chemically in the presence of light and oxidising