Gingerol
Also written gingerols, 6-gingerol
Quick answer
The pungent compound of fresh ginger, and the reason dried ginger is not simply fresh ginger with the water removed: drying converts it into a different, sharper compound.
What it does
Gingerol gives fresh ginger a bright, immediate, slightly sweet heat felt at the front of the mouth and in the throat. On drying it loses water to form shogaol, which is markedly more pungent and harsher, with the heat sitting further back; prolonged cooking additionally produces zingerone, which is much milder and frankly sweet. So a single rhizome yields three distinct pungency characters depending on what has been done to it, and the sensory difference between fresh, dried and long-cooked ginger is a chemical conversion rather than a matter of concentration.
How it behaves when cooked
Four properties of the molecule, and what they mean at the stove.
- Volatility
- low
- Fat solubility
- high
- Water solubility
- moderate
- Heat stability
- moderate
This is the clearest case in the catalogue of a compound that changes identity during cooking, and it settles the substitution question that follows. Dried ground ginger is not a stand-in for fresh in a dish where fresh ginger is the aromatic lift, because the conversion to shogaol has already happened and the bright top note is gone; equally, fresh ginger will not give a gingerbread the penetrating dry heat it is built around. Long, wet cooking pushes the balance towards the mildest of the three compounds, which is why a ginger braise tastes sweet and warming rather than sharp, and why ginger intended to bite is added late. The aroma of ginger, as distinct from its heat, comes from a separate volatile terpene fraction that does evaporate — so a long-cooked ginger dish loses its smell while keeping its warmth.
Spices that carry it
Recorded on the compound rather than on each spice, so the two cannot disagree.
- GingerPrincipal component
What cooking and processing were measured to do to it
Findings from studies in which this compound was followed through heat, fat, water, drying or storage. Each belongs to its study and its conditions.
Toasting and dry roasting · Converts Gingerol, Shogaol
Fresh ginger from one Korean farm held 6200 mg of 6-gingerol per kilogram of dry weight and only 29 mg of 6-shogaol. Dry heat in a convection oven moved gingerol towards shogaol, faster as the temperature rose from 100 to 130 °C. After 360 min at 130 °C the 6-gingerol in sliced fresh ginger had fallen from 6243 to 2877 mg/kg while 6-shogaol had risen to about 1350 mg/kg; the paper gives 1161 mg/kg for the same sample in a later passage.
Conditions: in air · 100, 110, 120 and 130 °C in a convection oven · 10 to 360 min · Fresh ginger in 5 mm slices and freeze-dried ginger powder, from one farm
Heat alone, without any drying step beforehand, shifts ginger from gingerol towards shogaol, but in this study the shift took hours at oven temperatures above the boiling point of water. A few minutes in a pan is a far smaller treatment than anything measured here.
What this does not show: One farm, one harvest and a laboratory oven, with heating times of up to six hours. The paper reports two different shogaol figures for the same sample. It measured the pungent compounds only, not taste, and did not measure zingerone.
Measured on the spice
Toasting and dry roasting · Converts Gingerol, Shogaol
Under the same dry heat, dried ginger powder converted more of its gingerol than sliced fresh ginger did. After 360 min at 130 °C the powder went from 6288 to 2265 mg of 6-gingerol per kilogram and reached 1611 mg/kg of 6-shogaol, significantly more than the slices. The authors attribute the difference to the energy the fresh slices spend evaporating their water before they can heat up.
Conditions: in air · 130 °C in a convection oven · 360 min · Freeze-dried ginger powder compared with 5 mm slices of fresh ginger
What this does not show: The powder was freeze-dried in the laboratory so that it began with almost no shogaol; commercially dried ginger already contains some. The explanation offered for the difference was proposed by the authors, not tested.
Measured on the spice
Steaming · Converts Gingerol, Shogaol
Moist heat converted gingerol to shogaol far more effectively than dry heat at the same temperature. After 360 min in an autoclave the 6-gingerol in sliced fresh ginger had fallen from 6258 mg/kg of dry weight to 4436 mg/kg at 100 °C, 2840 at 110 °C, 746 at 120 °C and 571 at 130 °C. The highest 6-shogaol content in the study, 2991 mg/kg, came from 360 min of moist heat at 120 °C, roughly twice what dry heat produced in the same slices.
Conditions: in steam · 100, 110, 120 and 130 °C in an autoclave · 10 to 360 min · Sliced fresh ginger under pressurised moist heat
At 100 °C, the temperature of a simmering pot, six hours of moist heat still left about seven tenths of the 6-gingerol in place. The large conversions in this study belong to pressurised heat above the boiling point.
What this does not show: An autoclave, not a pot: the ginger was heated in pressurised steam, not simmered in liquid, so nothing could leach out. One farm and one harvest. Zingerone was not measured.
Measured on the spice
Simmering and boiling · Converts Gingerol, Shogaol
In water, [6]-gingerol loses a molecule of water to give [6]-shogaol, and the reaction runs both ways: shogaol takes water back up to re-form gingerol until the two reach a balance. The rate depended on acidity, with gingerol most stable at pH 4. At 100 °C and pH 1 the reaction was relatively fast and reached equilibrium within 2 h. Shogaol was the major degradation product.
Conditions: in water · 37 to 100 °C · pH 1, 4 and 7 · Pure [6]-gingerol in aqueous solution, followed by HPLC
What this does not show: Read in the abstract only. A solution of the pure compound, studied for pharmaceutical purposes; pH 1 is far more acid than any food. The abstract gives no rate constants and does not report zingerone.
Measured on the pure compound
Blanching · Retains Gingerol, pungency
Blanching and freeze-drying had no measurable effect on the [6]-, [8]- and [10]-gingerol content of ginger, whereas cooking and processing it into paste and into senbei crackers significantly lowered all three. Gingerols in every product went on declining gradually in storage.
Conditions: in water · Fresh ginger and ginger products; gingerols extracted in methanol and measured by HPLC
What this does not show: Read in the abstract only, which gives directions and significance but no amounts, temperatures or times. It does not say what the lost gingerol became.
Measured on the spice
Drying · Converts Gingerol, Shogaol, pungency
Ginger dried in the open sun held more 6-, 8- and 10-gingerol than ginger dried in a solar tunnel or a hot oven, and less of the corresponding shogaols. Raising the oven temperature from 120 to 150 °C increased the shogaols sharply; at 180 °C both gingerols and shogaols fell, which the authors attribute to degradation and polymerisation. At 150 °C the shogaol content rose with drying time up to 6 h and dropped at 7 h. The order of shogaol formation was oven at 150 °C, then solar tunnel, then open sun.
Conditions: in air · Open sun at 23 to 34 °C; solar tunnel at 31 to 47 °C; oven at 120, 150 and 180 °C · Nine days in the sun; up to 7 h in the oven · Sliced rhizomes dried to about 10 per cent moisture
What this does not show: The oven temperatures are far above those used to dry ginger for the spice trade, so the oven results show the direction of the chemistry and not a commercial product. The values sit in a table and figures; the text read gives the comparisons and not every number. One source of rhizomes.
Measured on the spice
Drying · Depends on conditions Gingerol, Shogaol, volatile oil
Ginger powder of the variety Xiaolin Huangjiang dried in two stages, 90 min at 120 °C followed by 150 min at 80 °C, held 11.87 mg/g of the gingerol group measured (6-, 8- and 10-gingerol and 6-shogaol), against 7.12 mg/g after 360 min at a constant 80 °C. The slower constant drying kept far more volatile oil: 3.46 per cent against 1.29 per cent.
Conditions: in air · 120 °C then 80 °C, against a constant 80 °C · 90 min plus 150 min, against 360 min
A drying schedule that keeps ginger’s pungent compounds is not necessarily the one that keeps its aroma; in this comparison the two pulled in opposite directions.
What this does not show: Read in the abstract only. The figures given are for one of three varieties, and the abstract does not separate gingerols from shogaol in the total.
Measured on the spice
Not to be confused with
Compounds a reader is likely to take for this one, and why they differ.
Paradol
The pungent compound of grains of paradise, a close relative of gingerol rather than gingerol itself. The distinction was made because the grains-of-paradise profile records "paradol and gingerol relatives" and claiming gingerol proper would have been a small unearned upgrade of what that profile says.
Piperine
Grains of paradise and ginger are sometimes described as peppery. They are Zingiberaceae, contain no piperine, and their pungency is of a different chemical family entirely.
Questions this page answers
- what is gingerol
- what does gingerol do
- what is gingerols
- what is 6-gingerol