Chemical Compounds in Herbs & Spices

[Now available to purchase as herb/spice jar labels here!]

It’s often stated that cooking is much like chemistry, or vice versa. I thought it’d be fun to take that a little further, and look at the major organic compounds present in various different herbs and spices that are frequently used in cooking, so that’s what this poster tries to do. Obviously, each herb or spice owes its precise flavour to the complex mix of organic compounds it is composed of, rather than one simple compound that can be isolated – however, some compounds contribute more than others, and it is these that I’ve tried to focus on here.

The majority of the compounds I’ve selected have been chosen because they are the major compound present in that particular herb or spice. In a select few cases, however, I’ve selected one that isn’t the major compound; in these cases, this is because the compound chosen is a major contributor to either the aroma, flavour or colour of the spice in question. I’ve tried to provide a brief overview for each spice in the text below.

Basil

Estragole is an isomer of anethole, the compound found in anise. Basil oil contains a large quantity of estragole, along with the compound linalool. It is also found in herbal medicinal products.

Bay Leaves

1,8-cineole is the major constituent, a compound also found in cardamoms. Its common name is eucalyptol, the major compound found in eucalyptus oil. Eucalyptol is an ingredient added to cigarettes and is also found in many brands of mouthwash.

Caraway

Carvone, the major compound in caraway, actually has two mirror image isomers, one of which smells like caraway, the other of which smells like spearmint. Only S-carvone, the isomer smelling of caraway, is found in caraway seeds.

Cardamom

1,8-cineole is the major compound found in small cardamoms. The cardamom aroma is caused by the combination of this compound and another compound, alpha-terpinyl acetate.

Cayenne

Capsaicin is the major compound present in chilli peppers and gives them their spiciness. You can read more about capsaicin in the previous Chemistry of a Chilli post.

Chives

Similarly to onions and garlic, sulfur containing organic compounds give chives their flavour. One of the major contributors in chives is dipropyl disulfide.

Cloves

Eugenol is one of the main compounds found in cloves. More minor constituents are also contributors to the characteristic odour, for example compounds such as methylamylketone and methylsalicylate. Eugenol is named after the scientific name for cloves, and along with its derivative compounds is used in perfumery & flavourings.

Cinnamon

Cinnamaldehyde gives cinnamon its flavour and odour; 90% of the oil obtained from cinnamon bark is cinnamaldehyde. It is also used as a flavouring in chewing gum, sweets, ice cream and beverages.

Coriander Leaves

Once of the main components of cinnamon leaf oil extract is 2-decenoic acid. The composition also includes many different aldehydes, primarily those of 9-10 carbons in length. You can read more about the chemistry of coriander on the previous post on the site.

Coriander Seeds

The main compound in coriander seeds is linalool. It has two mirror image isomers, one of which is known as coriandrol. The other mirror image isomer is found in lavender and sweet basil.

Cumin

Cuminaldehyde is the main contributor to cumin’s warm aroma. Other constituents include a range of other aldehyde compounds.

Dill

Carvone, already mentioned for caraway, is also one of the main compounds found in dill. The spearmint isomer of carvone is used in the manufacture of chewing gum – spearmint chewing gum is produced by being soaked in carvone.

Ginger

Zingiberene is the major organic compound in ginger. The pungency of ginger is caused by a range of compounds called gingerols.

Lemongrass

Citral is a mix of two different isomeric aldehydes, neral and geranial. Citral is also used in perfumery for its citrus odour.

Mace

Mace’s chemical composition is similar to that of nutmeg, as they are both obtained from the same plant. The compound of the highest concentration in the essential oil of mace is terpinen-4-ol. It is also found in the essential oil of the tea tree.

Marjoram

Sabinene hydrate is the main component of the extracted oil of marjoram, and is responsible, along with other compounds of the terpene family, for the characteristic flavour of the herb.

Mint

The major compound in mint leaves is menthol. This compound is also a popular flavouring for chewing gum and toothpaste, and is also used in menthol cigarettes.

Nutmeg

Sabinene is one of the major constituents of the essential oil of nutmeg. Another compound found in nutmeg is myristicin, which can cause hallucinogenic effects in large amounts.

Oregano

Carvacrol is responsible for the warm, pungent odour of oregano. It is also found in tequila, and the oil of thyme.

Paprika

Capsanthin is one of the compounds that contributes towards the red-orange colour of paprika, as well as the compound capsorubin. These two compounds increase in concentration during the advanced stages of ripeness of peppers, increasing the intensity of their red colour.

Parsley

1,3,8-p-menthatriene is the major compound found in parsley leaves. Other compounds include myristicin & limonene.

Pepper

Piperine is the major constituent of the oil that can be extracted from black pepper, and is the main compound that gives black pepper its pungency. An isomer of piperine, chavicine, also contributes.

Rosemary

Alpha-pinene is found in many species of coniferous trees, notably the pine tree, as well as being one of the major compounds in rosemary. Along with other members of the monoterpene family of compounds, it is emitted in large amounts by vegetation.

Saffron

Crocin is the chemical compound responsible for the colour of saffron. It is a deep red colour, and forms an orange solution when dissolved in water. It has been shown to be a potent anti-oxidant.

Sage

Manool is one of the main chemical compounds found in sage. Others include eucalyptol, and thujone, a psychoactive compound.

Star Anise

80-90% of the essential oil extract of star anise is anethole. This can be isolated and used to flavour liqueurs such as sambuca, as well as liquorice sweets.

Tarragon

Estragole is an isomer of anethole, and is found in tarragon as well as basil. Estragole is suspected to be carcinogenic and genotoxic, but only at levels 100-1000 times the expected human exposure to the compound.

Thyme

Thymol is the compound that provides the distinct flavour of thyme. It is also used as one of many additives in cigarettes.

Turmeric

Compounds called curcuminoids are responsible for the yellow colouration of turmeric. They are also natural antioxidants. As a food additive, curcumin’s E number is E100.

Vanilla

The aroma of vanilla is mainly due to the compound vanillin, which accounts for 74-96% of the flavour & aroma compounds. Over 100 other volatile compounds have been detected, including acids, phenolic compounds, alcohols and aldehydes.

You can download the graphic as an A3 PDF here.

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References & Further Reading

• Gernot Katzer’s Spice Pages
• ‘The Chemistry of Spices’ – V. A. Parthasarathy
• ‘Essential Oil Variability in Sage’