Shogaols compound in ginger

Gingerols and shogaols are the chemesthetic compounds found in species from the Zingiber genus, ginger being the most common species. Shogaols, a monodehydrated gingerol was reported to be a pungent component of ginger.

Gingerols, through dehydration, form shogoals. Zingerone, a compound not found in fresh ginger, is formed by a retro-aldol reaction when gingerol is heated.

Usually, the fresh rhizome contains none or very small amounts of shogaols, while the dried rhizome is rich in shogaols. This suggests that shogaols are formed through dehydration during processing or storage of the fresh rhizome.

With formation of shogaols by the dehydration of gingerol, the pungency doubles - which is why aged ginger usually has a stronger bite.

HPLC is by far the most popular technique to separate and detect gingerols and shogaols in ginger.
Shogaols compound in ginger

Gingerols

Ginger contains gingerols and shogoals, which vary in proportion depending on the type of ginger used and storage conditions. Research suggested that gingerol is the most abundant principle of ginger.

Chemically, gingerol is a relative of capsaicin and piperine, the compounds that give chili peppers and black pepper their respective spiciness.

Fresh ginger and commercially processed dry ginger contain over 115 compounds of which major constituents in fresh ginger are gingerol-related compounds with 6-gungerol being the most abundant constituent.

Other gingerols are present in lesser amounts, such 4-, 8-, 10- an 12-gingerols an 6-gingerdione.

Ginger flavour is particularly interesting as changes can occur on storage, with gingerol dehydrating into shogoals and in turn shogoals can be cleaved into zingerone and hexanal, which adds to taste complexity. This is why age ginger usually has stronger bite.
Gingerols