Ginger is closely related to turmeric, cardamom and galangal. Similar to other plants, ginger is a very complex mixture of compounds, containing several hundred known constituents, including beta-carotene, capsaicin, caffeic acid and curcumin.
The pungency in ginger is derived from the principle compounds gingerol, shogaol and zingerone.
Gingerol is the active component in fresh ginger, and is related to capsaicin, which is the active component in chilli peppers. Zingerone – the least pungent compound – occurs when gingerol is cooked, while shogaol – which is twice as pungent – occurs when gingerol is dried.