November 29, 2021
You know me from Middle Eastern foods—and tacos.
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Image of Cuminaldehyde

November is flavor and aroma month!

Cuminaldehyde, an aromatic aldehyde, gets its name from one of its main natural sources: the cumin plant (Cuminum cyminum) that grows in countries from Turkey across to India. In addition to cumin, cuminaldehyde is found in the essential oils of eucalyptus, myrrh, and cassia.

In small amounts, cuminaldehyde has a pleasant, herbal aroma; however, it also has an acrid, burning taste. As the hazard information table shows, direct exposure can have some unpleasant consequences.

Cumin has been used as a flavoring agent for centuries; cuminaldehyde has been in the chemical literature since at least the 1880s. In volume 2 (1880) of the Journal of the American Chemical Society (then called the American Chemical Journal), an abstract of an article about derivatives of stilbene (1,2-diphenylethylene) describes a reaction between “cumic aldehyde” and phenylacetic acid to form isopropylstilbene.

Almost 70 years later, Nathan N. Crounse at the Hilton-Davis Chemical Co. (Cincinnati) reported a synthesis of cuminaldehyde that uses the high-pressure Gattermann–Koch reaction to formylate cumene (isopropylbenzene) with carbon monoxide. The aldehyde can also be prepared by the reduction of p-isopropylbenzoyl chloride.

Today, most commercial cuminaldehyde is synthetic. It is sold as an ingredient for flavoring agents, perfumes, and other aroma-containing products. It also has several purported medicinal uses (e.g., against pain, inflammation, nausea, and skin conditions), but the effects are largely anecdotal. A derivative, cuminaldehyde thiosemicarbazone1, has been studied for activity against the hepatitis C virus and colon cancer.

A final note: Cumin is the main flavor ingredient in taco sauce. The next time you go out for Taco Tuesday, you have cuminaldehyde to thank.

1. CAS Reg. No. 3811-20-9.

Cuminaldehyde hazard information*

Hazard class** GHS code and hazard statement
Flammable liquids, category 4 H227—Combustible liquid Chemical Safety Warning
Acute toxicity, oral, category 4 H302—Harmful if swallowed Chemical Safety Warning
Acute toxicity, dermal , category 4 H312—Harmful in contact with skin Chemical Safety Warning
Skin corrosion/irritation, category 2 H315—Causes skin irritation Chemical Safety Warning
Serious eye damage/eye irritation, category 2A H319—Causes serious eye irritation Chemical Safety Warning
Acute toxicity, inhalation, category 4 H332—Harmful if inhaled Chemical Safety Warning

*Compilation of selected safety data sheets.
**Globally Harmonized System (GHS) of Classification and Labeling of Chemicals. 
Explanation of pictograms.

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fast facts

CAS Reg. No. 122-03-2
Benzaldehyde, 4-(1-methylethyl)-
Empirical formula C10H12O
Molar mass 148.20 g/mol
Appearance Colorless to yellow liquid
Boiling point 235–236 °C
Water solubility Insoluble
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