Popcorn was popped conventionally in oil and in a microwave
oven without oil. Volatile components were collected by condensation
of popper headspace gases and by vacuum steam distillation of
a slurry of ground, popped corn in distilled water. The organic
compounds were extracted from the aqueous condensate and vacuum
distillate with diethyl ether. The concentrated ether extracts were
analyzed by a coupled gas chromatograph-mass spectrometer utilizing
three different procedures. These were: (1) a 300 foot by 0.01
inch ID capillary column, into which samples were injected with a
50:1 inlet split, with the effluent end connected directly to the ion
source of the mass spectrometer; (2) the same directly coupled
capillary column but with samples previously trapped from a packed
column introduced without splitting; (3) mass spectrometric analysis
of a portion (5 to 10%) of the effluent stream from a 12 foot by 1/8
inch OD packed column.
Thirty-six compounds were positively identified by comparison of their spectra with reference spectra. Relative retention time
coincidence with known compounds confirmed the mass spectral
identifications. Those compounds positively identified include pyrazine,
2, 5-dimethyl pyrazine, 2, 3-dimethyl pyrazine, 2-ethyl-5-
methyl pyrazine, 2-ethyl-3, 6-dimethyl pyrazine, 2-pentyl furan,
furfural, 2-acetyl furan, 5-methyl furfural, furfuryl alcohol, 5-hydroxymethyl
furfural, acetaldehyde, 2-methyl propanal, 5-methyl
butanal, pentanal, hexanal, benzaldehyde, phenylacetaldehyde,
diacetyl, ethyl acetate, methyl palmitate, diethylphthalate, ethanol,
hexane, acetic acid, hexanoic acid, palmitic acid, γ-kutyrolactone,
N-furfuryl pyrrole, N-furfuryl pyrrole-2-aldehyde, 2-acetyl pyrrole,
pyrrole-2-aldehyde, 4-vinyl-2-methoxyphenol, 4-vinylphenol, and
vanillin. Another 20 compounds were tentatively identified on the
basis of their mass spectra. These were 2, 3, 5-trimethyl pyrazine,
2-acetyl pyrazine, (5-methyl-2-furyl)-(2 furyl)-methane, 5-methyl-
2-acetyl furan, bi-(5-methyl-2-furyl)-methane, 4-hydroxy-2, 5-dimethyl-3 (2H)-furanone, heptanal, ethyl formate, pyridine, thiazole,
benzothiazole, ethylbenzene, a dichlorobenzene, N-ethylpyrrole-
2-aldehyde, N-isoamyl-pyrrole-2-aldehyde, 5-methylpyrrole-
2-aldehyde, 2-formyl-5-methylthiophene, 2-ethyl-5-butylthiophene,
phenol, and 2-methoxyphenol.
It is believed that pyrazines, furans, carbonyls, and phenolic
compounds make important contributions to the flavor and aroma of popcorn. The presence of many of the compounds identified can be
explained by their production during popping from precursors in the
popcorn kernels by Maillard browning reactions, Strecker degradation
of amino acids, thermal oxidation and hydrolysis of lipids, and
direct thermal degradation of plant constituents. / Graduation date: 1969
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26817 |
| Date | 05 May 1969 |
| Creators | Walradt, John Pierce, 1942- |
| Contributors | Lindsay, Robert C. (Robert Clarence), 1936- |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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