Previously, it has not been possible to obtain a concentrated
ripe Bartlett pear essence. From studies of
Bartlett pear aroma characteristics, it was found that
methyl and ethyl decadienoates are the components contributing
to the characteristic ripe Bartlett pear aroma. It
was also found that only perfume-like aroma products,
lacking in typical Bartlett pear aroma, could be obtained in
the early pear essence recovery trials. Thus, a laboratory
scale fruit essence recovery unit was designed and built to
study the difficulties in pear essence recovery.
Water was first used to calibrate the unit, then, apple
juice was applied as a testing model to establish the basic
essence recovery effectiveness of the unit. It was found
that the high heat provided by the reboiler, would drive the
high-boiling, low-volatile pear aroma components upward to
the fractionating column top where they could be recovered
as overhead product. The high-boiling compounds were found
in the reboiler discharge water in the low-heat tests.
A good, strong and characteristic ripe Bartlett pear
essence was obtained in the high-heat pear essence recovery
test. A concept of separating low-boiling alcohols from
high-boiling esters, to avoid the interference from low-boiling
alcohols in the concentrating high-boiling esters.
was substantiated through developing a two-stage essence
recovery unit. Characteristic Bartlett pear essence of 100
fold was produced successfully in the two-stage test.
Along with the organoleptic evaluation, the essence product
was also analyzed by GC-MS and UV spectrometry to confirm
the presence of "decadienoates" — characteristic Bartlett
pear aroma components. This is the first time that a
typical and good quality ripe Bartlett pear essence of
100 fold has been recovered. / Graduation date: 1981
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27478 |
| Date | 22 January 1981 |
| Creators | Miaw, Mei-chen |
| Contributors | Beavers, D. V. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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