The retention of pigments in processed raspberries is
a function of the process method and conditions of subsequent
storage. The presence of sucrose and the nature of the
headspace gas also influences the retention of the pigment.
The effect of some of the above variables on the pigments was
investigated. Variables imposed were: (1) concentration of
syrup, (2) headspace gas atmosphere, (3) temperature, and
(4) time of storage. Separation of the pigment of Willamette
red raspberries and black raspberries was made by column
chromatography and the pigments were analyzed.
spectrophotometrically.
The results showed the following:
1. The pigments of Willamette red raspberries consisted
of four separate cyanins as based on the R [subscript f] values and
characteristic wavelengths of maximum absorption. The pigments
of black raspberries consisted of three fractions.
2. On the basis of R [subscript f] values and wavelengths of
maximum absorption only two of the constituent fractions were
the same.
3. The wavelength of maximum absorption of all the
anthocyanins shifted towards shorter wavelengths after the
first month of storage.
4. Time and temperature of storage and their interaction
each contributed significantly to the destruction of the
cyanin pigments. An increase in either variable resulted in
a greater destruction of the pigments.
5. As the concentration of the ingoing syrup was increased,
the amount of individual cyanins decreased.
6. Oxygen in the headspace gas was shown to be
detrimental to the retention of the cyanins I, II, and IV of
the Willamette raspberries and to cyanins II and III of the
black raspberries.
7. Changes in the total pigment concentration were
greatly influenced by the cyanin in greatest concentration in
the species.
8. Heat processing destroyed approximately 20
percent of the pigments of the raspberries. / Graduation date: 1963
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26670 |
| Date | 14 May 1963 |
| Creators | Daravingas, George Vasilios |
| Contributors | Cain, Robert F. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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