The aroma of Tuber gibbosum, a native Oregon truffle, was
characterized using two distinct techniques. Volatile aroma
constituents were identified by chemical analysis, and sensory
characteristics were determined by examining response of the
general populace to the truffle aroma.
Truffle samples from four maturity ranges, as determined
by microscopic examination of each specimen for spore maturity,
were compared for amounts and types of aroma volatiles present.
Aroma volatiles of frozen specimens of T. gibbosum were sampled
using a headspace concentration technique. Volatile compounds
were analyzed by gas chromatography/mass spectrometry/data system
(GC/MS/DS) and the total volatile profile was found to contain up
to 20 compounds, depending on sample treatment and maturity.
Seven compounds were found to be the major aroma constituents and
were selected for further investigation. These 7 compounds were
identified from their mass spectra and the identities
substantiated by determining their Kovats retention indices. Amounts of volatile compounds present in each sample were
determined by capillary gas chromatographic (GO analysis using an
internal standard of n-tridecane for quantitative determinations.
The major aroma constituent for all the samples was oct-l-en-3-ol,
representing about 50% of the total aroma profile. The other 7
major components were 8- and 6-carbon alchols, ketones and
aldehydes.
Quantitative data for all samples and components were
analyzed statistically. A descriptive model for truffle maturity
was derived based on the amounts of 5 of the 7 compounds, and the
sum of the amounts of the 7 major constituents.
A comparison of volatiles from ascorbic acid treated and
untreated control truffle samples indicated an apparent reduction
in the amounts of several compounds.
The examination of public response to the aroma of T.
gibbosum was conducted as part of a display on truffles at the
Oregon Mycological Society Mushroom Show. The aroma of this
truffle, and three other native Oregon truffles were rated for
desirability and preference. Results indicate T. gibbosum was not
the favored sample, but was liked by about 2/3 of the population.
Comparison of responses by males and females showed no differences
for individuals liking the truffle aromas. However, females rated
the truffle aromas of 3 of the 4 species as more unpleasant than
did males. / Graduation date: 1986
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27224 |
| Date | 19 August 1985 |
| Creators | Marin, Anna B. |
| Contributors | Libbey, Leonard M. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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