Carrots were cooked to the just tender stage in a saucepan and
in a pressure saucepan for appropriate lengths of time to make them
approximately equal in tenderness as determined by a panel of
judges and the Kramer Shear Press. A third lot of carrots was
cooked in a pressure saucepan for approximately twice as long to
represent overcooked carrots. Judges and the Hunter Color Meter
indicated that the carrots cooked in the saucepan were more typically
red-orange and bright and the carrots overcooked in the pressure
saucepan were more yellow and dull.
Pigments extracted from the carrots from the three cooking
treatments were chromatographed on a magnesia column and the
principle fractions, α-carotene and β-carotene, eluted. The β-carotene was rechromatographed on an alumina column to separate it into all-trans-β-carotene and neo-β-carotene B. In absolute amounts,
carrots cooked in the saucepan had the highest concentration
of all-trans-β-carotene and the highest total of all-trans-β-carotene,
neo-β-carotene B and α-carotene, followed by those carrots cooked in
the pressure saucepan for 50 seconds, with those cooked in the pressure
saucepan for two minutes being lowest in both all-trans-β-carotene
and total carotenes. However, when the a-carotene, the neo-pcarotene
B and the all-trans-β-carotene were considered as percentages
of the total, the percentage of α-carotene remained constant in
the three treatments. Carrots cooked in the pressure saucepan for
two minutes had a lower percentage of all-trans-β-carotene and a
higher percentage of neo-β-carotene B than did carrots from the
other two treatments. Thus, longer cooking in the pressure saucepan
caused greater conversion of the more vivid all-trans-β-carotene to
the paler cis-isomer, neo-β-carotene B. This isomerization plus
loss of total pigment accounts for the differences in color of the cooked
carrots from the three treatments. / Graduation date: 1964
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26681 |
| Date | 13 April 1964 |
| Creators | Borchgrevink, Nancy Carter |
| Contributors | Charley, Helen |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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