The use of gas chromatography for the separation, comparison,
and subsequent identification of flavor volatiles from food
products has proven highly successful in recent years. The
development of various techniques for the concentration of the
volatiles before gas chromatographic analysis has greatly extended
the use of this important analytical tool.
The injection of vapors directly into the chromatograph
without prior concentration is the simplest method and has been
used successfully on many food products. However, the use of
this technique on the volatiles of fishery products has met with
limited success. The complexity and nature of the flavor compounds
found in fishery products have required the use of highly
sensitive instruments and columns with very efficient separation
power. The purpose of this investigation was to develop a method
for the separation and comparison of volatiles from fishery products
by this direct vapor injection technique.
Preliminary investigations showed that a nine foot column
of diisodecyl phthalate on 80/100 mesh, methanoic KOH treated,
celite 545, operated isothermally at 35°C, would give satisfactory
separation of one to three ml samples of volatiles from heated
fishery products. The technique was not, however, sensitive
enough to allow direct sampling of cold products unless they were
highly spoiled or autoxidized.
This investigation showed that direct vapor injection, using
the column and conditions described, will show differences between
size and number of peaks in heated fresh, oxidized, and spoiled
fishery products. Several peaks in autoxidizing menhaden oil were
shown to increase with hours of oxidation and a peak with the same
retention time as trimethylamine was observed in the chromatograms
of spoiled fish. The direct injection technique did not show
large differences between fresh dover sole, rockfish, oysters, or
beef.
Tentative identification of various peaks from the chromatograms
of oxidized salmon oil was attempted by comparison of retention
data to known compounds and by functional group analysis
by the method of Hoff and Feit (34). In this manner the possible
existance of C₁ to C₇ alkanals, 2-hexen-1-al, methane, heptane,
ethanol, butanol, and acetone was shown. The methods of tentative
identification used were preliminary in nature and confirming tests
would be necessary before positive identifications could be made.
A comparison of chromatograms from fish, oysters, beef,
and fish oils showed that several similar peaks appear in every
case. These peaks were found at retention times of 0.71, 0.87,
1.42, 2.21, 2.83, 3.62, 5.20, and 5.51 minutes. / Graduation date: 1964
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26682 |
| Date | 28 April 1964 |
| Creators | Hilderbrand, Kenneth S. |
| Contributors | Sinnhuber, Russell O. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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