Stigmata from ~ 150 flowers make 1 gram
HOW DOES SAFFRON ACT IN PROTECTING TISSUES?
Saffron is of interest to the medical scientist, because of its high content of anti-oxidants. Many plants, probably all, contain some anti-oxidants, but, weight-for-weight, saffron is the most anti-oxidant plant known.
On the other hand, several lines of evidence suggest that the direct or chemical anti-oxidant power of saffron is not important for its tissue-protective effects. Rather, saffron seems to interact with the genes of tissue cells. It is believed to upregulate a number of biochemical pathways which activate self-protective mechanisms in individual cells.
However, the number of studies of mechanisms is limited, and understanding is incomplete.
In addition, several studies have begun to test which of the biologically active molecules found in saffron are important in its action. Studies to date have concentrated on compounds called crocin, crocetin and safranal, which have strong anti-oxidant power.
Much remains to be learnt, however.
When saffron is seen with the stigmata en masse, you get some impression of why it is so costly. The flowering is brief, and the stigmata must be hand-picked within a day or two. Automation is not possible, and harvesting has not changed over the centuries.
In some traditions, the land used is left fallow for several years between planting, reducing the annual yield.