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Happy Thanksgiving! If you are like many of us, sweet potatoes (aka yams) are one of the highlights of your Turkey Day meal. The aroma of a casserole baking in the oven adds to that comfort-food feeling.
A chemist would naturally ask, 鈥淲hy do roasting or baking sweet potatoes smell so good?鈥� Ola Lasekan* and Li Shing Teoh at University Putra Malaysia (Serdang), identified in roasting white yam (Dioscorea rotundata)1. Among them, the two that had the highest odor activity factors were 2-acetylfuran (2AF, aka 2-furyl methyl ketone) and 2-acetylpyrrole (2AP, aka 2-pyrrolyl methyl ketone).
According to the authors, 2AF 鈥渆licited an almond-like note鈥� whereas 2AP had 鈥渁 popcorn-like note鈥�. The aromas emitted by the other components, mostly furans, pyrroles, and pyrazines, were given labels such as 鈥渢oasty鈥�, 鈥渃aramel鈥�, 鈥渃hamomile flower鈥搇ike鈥�, and 鈥渟moky鈥�.
The focus of this study was to identify the aroma compounds that contribute to the potatoes鈥� antioxidant properties. Using an established test based on substances鈥� ability to inhibit the oxidation of hexanal, the authors found that the pyrrole-containing aroma components were substantially superior antioxidants to the furans and especially the pyrazines.
A glance at the hazard information tables shown here might give you pause. 2AF in particular looks as if it might kill you as you鈥檙e enjoying the holiday. But rest assured that these, like many other odorous substances, are detectable in air at very low concentrations.
So, this Thanksgiving Day, while you鈥檙e watching the virtual Macy鈥檚 parade and NFL football games, take satisfaction that some of the food aromas you鈥檙e inhaling add to your antioxidant supply.
1. Full disclosure: Dioscorea spp. are 鈥渢rue yams鈥�, as opposed to the orange-colored sweet potatoes (Convolvulaceae spp.) that some Americans call yams. The baking and roasting aromas of both yam genera contain 2AF and 2AP.
2-Acetylfuran hazard information
Hazard class* | Hazard statement | |
---|---|---|
Flammable liquids, category 4 | H227鈥擟ombustible liquid | |
Acute toxicity, oral, category 2 | H300鈥擣atal if swallowed | ![]() |
Acute toxicity, dermal , category 3 | H311鈥擳oxic in contact with skin | ![]() |
Serious eye damage/eye irritation, category 1 | H318鈥擟auses serious eye damage | ![]() |
Acute toxicity, inhalation, category 2聽 | H330鈥擣atal if inhaled | ![]() |
*Globally Harmonized System of Classification and Labeling of Chemicals.聽聽
2-Acetylpyrrole hazard information
Hazard class* | Hazard statement | |
---|---|---|
Acute toxicity, oral, category 4 | H302鈥擧armful if swallowed | ![]() |
Skin corrosion/irritation, category 2 | H315鈥擟auses skin irritation | ![]() |
Specific target organ toxicity, single exposure, respiratory tract irritation, category 3 | H335鈥擬ay cause respiratory irritation | ![]() |
*Globally Harmonized System of Classification and Labeling of Chemicals.聽聽
2-Acetylfuran fast facts
CAS Reg. No. | 1192-62-7 |
nomenclature | Ethanone, 1-(2-furanyl)- |
Empirical formula | C6H6O2 |
Molar mass | 110.11 g/mol |
Appearance | Yellow to brown liquid or solid |
Melting range | 26鈥�33 潞C |
Boiling point | 175 潞C |
Water solubility聽 | Very slight |
2-Acetylpyrrole fast facts
CAS Reg. No. | 1072-83-9 |
nomenclature | Ethanone, 1-(1H-pyrrol-2-yl)- |
Empirical formula | C6H7NO |
Molar mass | 109.13 g/mol |
Appearance | White to beige crystals or powder |
Melting point | 90.0鈥�90.5 潞C |
Water solubility聽 | 274 g/L |

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