Wines were made from Pinot Noir and White Riesling grapes
which had received field application rates of 2 and 4 lb./acre of the
experimental bird repellent Mesurol (methiocarb or 3, 5 dimethyl-
4(methylthio)phenylmethylcarbamate). In addition, Pinot Noir must
and press juice and White Riesling press juice were fortified with
15 ppm Mesurol (active ingredient) and vinified.
Mesurol and its sulfoxide and sulfone metabolites were determined
by gas chromstographic analysis as mesylate derivatives
following fractionation on Florisil. Residues were also oxidized to
and expressed as total sulfone.
Mesurol residues, methiocarb and total sulfone, in field treated
grapes sprayed with 4 lb./acre Mesurol exceeded the 15 ppm temporary
tolerance established by the Environmental Protection Agency.
Methiocarb residues in pomace, calculated on a dry weight basis,
obtained from grapes harvested one day after the final application of
Mesurol were in excess of the 75 ppm EPA temporary tolerance.
Approximately 40 to 51% of the methiocarb residues measured
in field, treated grapes remained associated with the pomace after
pressing. Finished Pinot Noir and White Riesling wine, prior to
bottling, contained in the order of 3-8 ppm representing 34 to 49%
and. 13%, respectively, of the methiocarb residues originally present
in grapes.
The fate of Mesurol sulfide, sulfoxide and sulfone residues during
the processing of Mesurol fortified White Reisling press juice was
investigated. Settling of press juice was found to reduce methiocarb
residues. Oxidation during vinification was minimal.
Mesurol sulfide, sulfoxide, and sulfone residues in finished
wine remained unchanged after 12 months of storage at cellar temperatures.
Trace amounts of Mesurol sulfide phenol were detected
with Mass Spectrometry.
Volclay bentonite (KWK) fining at 4 and 8 lb./1000 gal. and
membrane filtration (0.45 μ) were not effective in reducing Mesurol
residues in wine.
Reference-difference tests were used to evaluate the effect of
Mesurol on finished wine sensory qualities. The sensory properties
of wines made from grapes harvested seven days after the last application
of Mesurol and Mesurol Fortified must and juices were not
affected. Also, the chemical composition of these wines was not
altered.
Lag time and fermentation rate of Mesurol Fortified. Pinot Noir
must and juice processed into wine were not affected. The course of
fermentation in the presence of Mesurol was also monitored by
recording mass loss in model studies. A slight inhibition in fermentation
rate was observed, at levels below 25 ppm while a stimulation
was evident at concentrations of up to 500 ppm. / Graduation date: 1981
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27479 |
| Date | 23 May 1980 |
| Creators | Miller, Frederick Kenton |
| Contributors | Heatherbell, D. A. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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