Processing and storage of berry fruits is accompanied by various
changes, the important ones being the changes in the soluble solids
content, titratable acidity, pH, pigments, and texture. A study was
made of these changes in processed strawberries, raspberries, blackberries
and blueberries, still cooked and stored at 78°F for one and
six months in No. 10 cans. Three samples of the above four berries
were analyzed before processing, immediately after processing and
after one and six months of storage at 78°F. Five samples of syrups
were collected from both center and side of the cans by means of 50
ml pipettes. These five samples were from top, 1 3/4", 3 l/2", and
5 1/4" from the top and from the bottom and a mean sample was taken
from the drained syrup. The cans were then drained on an 8 mesh
10" screen. 100 gram samples of the drained solids from top, middle
and bottom were collected for texture measurements.
The results indicated the following:
1. There is a decrease in soluble solids of the syrup and drained
weight of the fruit immediately after processing. Softening of berries
progresses with storage.
2. There is an increase in titratable acidity, pH and pigments of the
syrup immediately after processing. Titratable acidity and pigments
increase with storage and pH values were lower.
3. There is a tendency to reach an equilibrium in the can with regards
to soluble solids in all berries and pigments in case of strawberries
with a lower tendency for raspberries. In the case of titratable acidity
equilibrium was almost realized in strawberries and blueberries. All
berry packs showed no equilibrium in the pH value after six months.
4. No noticeable differences between samples collected from centers
and side of the can. / Graduation date: 1963
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26669 |
| Date | 08 March 1963 |
| Creators | Boziotis, Constantinos Andreas |
| Contributors | Dietz, James H. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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