Winter 2007 Newsletter

What's in a Fruitcake?

Fearless Chemir scientists tackled the challenge of identifying the components and measuring the density of a store-bought fruitcake.

Head Space Analysis

A fruitcake sample was analyzed by headspace GC/MS (see chromatogram), a technique used to identify volatile compounds in a sample that fills the headspace of the container. These types of compound sare often the molecules responsible for odor and flavor.

Many compounds were identified in the fruitcake headspace. The most abundant compound was isopropenyl acetate. Isopropenyl acetate is not normally found in nature but it does have a "fruity" odor similar to some tropical fruits. Several other esters were also observed including: ethyl acetate, propanoic acid ethyl ester, and butanoic acid ethyl ester. A list of the major analytes identified is contained in the table below.

Analyte	Synonym	Retention Time	Odor
isopropenyl acetate (major)		2.523 min	Fruity
ethyl acetate		3.059 min	Grape, cherry
isovaleraldehyde	methyl butanal	3.345 min	Peach
ethanol	ethyl alcohol	3.441 min
propanoic acid, ethyl ester	ethyl propionate	3.679 min	Fruity, sweet
butanoic acid, ethyl ester	ethyl butyrate		Fruity, sweet
acetic acid		8.174	Vinegar
propanoic acid	propionic acid	8.961	Pungent acidic

The combination of these aldehydes, esters and other volatile organic molecules gives fruitcake its unique aroma and flavor.

Density Testing

A density determination of the fruitcake purchased by Chemir revealed that the cake component of the fruitcake had a density of 1.26 g/cm3. No nuts or dried fruits from the cake were analyzed. Whereas water has a typical density of 1.00 g/cm3, this demonstrates that fruitcake is heavier than water. For more comparisons, see the density chart below.

Item	Density (g/cm3)
Ice	0.90
Water	1.00
Milk	1.04
Fruitcake	1.26
Sugar	1.59
Lead	11.35

Conclusion

As with all holiday refreshments, enjoy fruitcake with moderation.