Ultrafiltration of d'Anjou pear juice in the batch mode with a
Romicon HFXS MXII pilot-scale ultrafilter produced a "sparkling clear",
light-colored permeate which was sterile, essentially free of pectin,
and lower in phenolics than the feed juice. Retention characteristics
of PM-50, PM-30 and PM-10 hollow fiber membranes were tested at a volume
concentration ratio of 1.14. No differences in retention characteristics
were found; the membranes were completely permeable to sugars,
malic acid and α-amino compounds and semipermeable to pectic substances
and phenolics. Filtration temperatures of 15°C, 30°C and 50°C did not
affect retention characteristics. The higher temperature did reduce
the number of microorganisms in the retentate. Transmembrane pressures,
varying from 103 to 153 kPa, also did not affect composition of the
permeate.
The effects cf filtration time (as volume concentration ratio)
were tested with a PM-50 membrane at 50°C with a transmembrane pressure
of 153 kPA. Flux declined as the log of volume concentration ratio.
With increasing filtration time, retention efficiency for pectic
substances and phenolics decreased. The permeates became more golden
in color but remained clear. Loss of efficiency was attributed to
concentration polorization. Pectic substances were thought to be
the major contributor to the formation of the gel layer. / Graduation date: 1982
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26006 |
| Date | 10 August 1981 |
| Creators | Hodgson, Jeanne |
| Contributors | Montgomery, Morris W. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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