Capsanthin
Also written capsanthin and capsorubin, capsorubin, capsicum carotenoids
Quick answer
The red carotenoid of ripe peppers — the reason paprika, Kashmiri chilli and gochugaru are bought for their colour, and the reason they must be kept in the dark.
What it does
Capsanthin, with the related capsorubin, gives ripe Capsicum fruit its deep red. It has no flavour and no aroma: it is purely a colourant, and it is entirely independent of capsaicin, which is why a chilli can be brilliantly red and completely mild. That independence is the whole basis of several spice industries — Kashmiri chilli, Hungarian and Spanish paprika, and Korean gochugaru are all cultivars selected to maximise colour while keeping heat within a usable range, so that they can be used by the spoonful.
How it behaves when cooked
Four properties of the molecule, and what they mean at the stove.
- Volatility
- low
- Fat solubility
- high
- Water solubility
- low
- Heat stability
- low
Carotenoids are strongly fat-soluble and not water-soluble at all, which is why paprika is stirred into hot fat to release its colour and why paprika added to a watery liquid gives a muddy orange suspension instead of a red dish. They are also unusually vulnerable to two things: light, which bleaches them steadily in a jar on a windowsill, and heat above a fairly low threshold, which destroys both the colour and the sugars in the same powder. This is why the Hungarian and Spanish instruction is universally to take the pan off the heat before the paprika goes in — a few seconds in genuinely hot fat turns paprika brown and bitter, and the bitterness cannot be removed. The combination of high fat solubility and low light stability is also why these are the spices where storage advice matters most: they lose their entire reason for existing to a sunny shelf while looking, at first, merely a little faded.
Spices that carry it
Recorded on the compound rather than on each spice, so the two cannot disagree.
- GochugaruPrincipal component
- Kashmiri chilliPrincipal component
- PaprikaPrincipal component
- Smoked paprikaPrincipal component
The graded property, and the reason the product is sold in tins: the carotenoids photo-degrade, so a faded tin has lost what it was graded on while still smelling strongly of smoke.
- Ají amarilloMajor component
Half the reason the chilli is used in quantity: a huancaína sauce is expected to be a particular yellow-orange, and the pigment survives the blanching that removes the heat because it is not water-soluble.
- Aleppo pepperMajor component
- AnchoMajor component
- Cayenne pepperMajor component
- Piment d'EspeletteMajor component
- GuajilloMajor component
- Chile de árbolContributing component
- Calabrian chilliContributing component
- Chilli flakesContributing component
- Chilli powderContributing component
- MulatoContributing component
- PasillaContributing component
- RocotoContributing 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.
Frying and blooming in fat · Depends on conditions Capsanthin, Capsanthin 5,6-epoxide, 13-Z carotenoid isomers, colour
Frying chilli powder in oil at 130 °C for 10 min transferred 97.0 per cent of its capsanthin and 93.2 per cent of its total carotenoids into the oil. At higher temperatures far less pigment survived: 37.1 per cent of the capsanthin at 150 °C, 23.1 at 170 °C and 14.9 at 190 °C. As the temperature rose, capsanthin 5,6-epoxide and 13-Z isomers increased, the red carotenoids were lost faster than the yellow, and browning products built up.
Conditions: in oil or fat · 130, 150, 170 and 190 °C · 10 min · Chilli powder fried in four times its weight of oil; proton NMR
The red of chilli moves into oil almost completely at a moderate frying temperature and is destroyed by a hot one. Pigment and pungency did not share an optimum in this study: the colour was best extracted at 130 °C, the heat at 150 to 170 °C.
What this does not show: One chilli powder and ten minutes of frying, much longer than a spice spends in a tempering. The study did not test temperatures below 130 °C, so it cannot say where extraction begins to fall off at the cool end.
Measured on the spice
Frying and blooming in fat · Retains Capsaicin, Capsanthin, colour, pungency
The carotenoids and capsaicinoids of chilli held up better under heat in an oil-based system, a hot pot base, than in a water-based one, chilli juice. Ultraviolet light significantly reduced both groups of compound in both systems, and storage at 4 °C significantly slowed their loss.
Conditions: in oil or fat · Hot pot base (oil system) compared with chilli juice (water system) under heat, light and storage
What this does not show: Read in the abstract only, which gives no figures or temperatures. The two systems differ in more than their medium, so the comparison is between two foods, not between oil and water alone.
Measured on the spice
Simmering and boiling · Decreases Capsanthin
In diluted paprika juice held at 80, 90 and 100 °C, capsanthin declined with heating time, and the kinetic model fitted to the data predicted half-lives of 27.47, 21.23 and 15.23 min at the three temperatures for juice containing 2850 mg of capsanthin per litre.
Conditions: in water · 80, 90 and 100 °C · Held for 0 to 16 min · Diluted paprika juice; capsanthin by HPLC
What this does not show: Read in the abstract only. A juice of the fresh fruit, a water system, not paprika powder dispersed in the fat of a dish. The half-lives are model predictions from heating runs of at most 16 min.
Measured on the spice
Frying and blooming in fat · Decreases Capsanthin, colour
Paprika oleoresins lost pigment at every temperature tested, and more quickly the warmer they were held, but the loss was not even across the pigments. Below 60 °C the yellow carotenoid fraction was destroyed faster than the red; above 60 °C the order reversed and the red fraction became the less stable. Heating above that temperature therefore shifts the remaining colour towards yellow.
Conditions: in oil or fat · Four temperatures, either side of 60 °C · Four paprika oleoresins
What this does not show: Read in the abstract only, which gives no rates or times. An oleoresin, the extracted pigment in its own oil, not the ground spice.
Measured on the spice
Drying · Depends on conditions Capsaicin, Capsanthin, Dihydrocapsaicin, pungency, colour
Whole chillies of two Guizhou varieties held significantly more capsaicin and dihydrocapsaicin after hot-air drying at 75 °C for 12 h than after five days in the sun or twelve days in the shade; the highest content, 1.71 mg/g, was in hot-air-dried Xianjiao. Capsanthin followed the same order, highest after hot air and lowest after shade-drying. The authors attribute the result to time: the slow methods leave enzymes active and oxidation running for days.
Conditions: in air · Hot air at 75 °C; sun at 25 to 33 °C; shade at 18 to 25 °C · 12 h; about 5 days; about 12 days · Two Guizhou varieties, whole fruit dried to about 7 per cent moisture
For a whole chilli, the long exposure of slow drying can cost more pigment and pungency than the heat of a quick one.
What this does not show: One season and three treatments that differ in several ways at once. The same study found shade-drying gave the richer aroma profile, so the ranking depends on what is valued. Conflicts with the finding on halved chillies that higher temperature lost more capsaicinoid.
Measured on the spice
Decontamination · Retains Capsaicin, Capsanthin, hexanoic acid, tetramethylpyrazine, 1,3-di-tert-butylbenzene, microbial load, colour, pungency
Gamma irradiation of vacuum-packed Korean red pepper powder at 7 kGy reduced mesophilic bacteria and fungi effectively. Pungency was unchanged, by capsaicinoid content and by Scoville score, and the red colour did not differ significantly from the control by capsanthin content, ASTA units or Hunter values. A panel found no significant difference in pungent odour or off-odour. Instruments could nonetheless tell the doses apart: the headspace profiles separated at 0, 3, 5 and 7 kGy, with hexanoic acid and tetramethylpyrazine disappearing and 1,3-di-tert-butylbenzene appearing, a compound the authors trace to the irradiated packaging film migrating into the powder.
Conditions: Up to 7 kGy of gamma irradiation; powder vacuum-packed in a polyethylene/polypropylene bag
What this does not show: Read in the abstract only. A later study by another group reported that most panellists did detect an off-flavour in irradiated red pepper powder, so the sensory result is not settled. The packaging finding belongs to that film.
Measured on the spice
Decontamination · Retains Capsaicin, Capsanthin, microbial load, colour, pungency
Red pepper powder irradiated with gamma rays, electron beams or X-rays lost total aerobic microbes in proportion to the dose, and 6 kGy from any of the three sources reduced the population effectively. None of the three changed the capsaicinoid content, and neither capsanthin content nor Hunter colour values differed significantly from the control. A sensory panel found no significant difference in pungent odour or colour, but most panellists detected an off-flavour in the irradiated samples from every source.
Conditions: Gamma rays, electron beams and X-rays at doses up to 10 kGy
What this does not show: Read in the abstract only, which does not describe the off-flavour or the dose at which it appeared. An earlier study found no significant difference in off-odour at up to 7 kGy; the two used different panels and doses.
Measured on the spice
Storage · Decreases Capsaicin, Capsanthin, dihydrocapsaicin, capsorubin, zeaxanthin, β-carotene, β-cryptoxanthin, pungency, colour
In a traditional Himalayan paprika stored under ambient conditions, total capsaicinoids and phenolic acids decreased significantly with storage, and so did the carotenoids. In the samples irradiated at 9 kGy, dihydrocapsaicin fell by 23.3 per cent and capsaicin by 21.0 per cent. Among the pigments, capsorubin fell least, by 19.2 per cent, against 29.9 per cent for capsanthin, 28.5 per cent for zeaxanthin and 29.5 per cent each for β-carotene and β-cryptoxanthin.
Conditions: Up to 9 months · Ambient conditions; figures are for samples irradiated at 9 kGy
In this paprika the pungent compounds were not indefinitely stable on the shelf: about a fifth was gone within the storage period, a smaller loss than that of the pigments but a real one.
What this does not show: Read in the abstract only. The percentages are given for the irradiated samples; those for the untreated control are not in the abstract, and neither are the packaging, temperature or humidity.
Measured on the spice
Not to be confused with
Compounds a reader is likely to take for this one, and why they differ.
Capsaicin
Colour and heat in the same fruit, bred independently and unrelated chemically. The single commonest wrong inference about chillies is that a redder one is a hotter one.
Annatto (bixin)
The other red-orange spice colourant, from an unrelated plant, used for much the same purpose in Latin American and Caribbean cooking. It is not a capsicum carotenoid and it colours towards orange rather than red.
Questions this page answers
- what is capsanthin
- what does capsanthin do
- which spices contain capsanthin
- what is capsorubin
- what is capsicum carotenoids