Sterile fish muscle homogenate was prepared from the individually
line caught black rockfish (Sebastes melanops) and inoculated
with the pure culture of Pseudomonas putrefaciens strain 17. The
inoculated homogenate was incubated at 5°C and the growth and production
of volatile sulfur compounds determined by a combined gas-liquid
chromatography and mass spectrometry.
A column containing 90-100 mesh diatomaceous earth coated
with 10% Carbowax 20M was developed and tested for the quantitative
determination of dimethyl sulfide (DMS), dimethyl disulfide (DMDS)
and dimethyl trisulfide (DMTS).
The DMDS levels in fish homogenate closely paralleled that of
P. putrefaciens growth. The maximum DMDS level of 2.00 μg per
100 g fish homogenate was obtained after 10 days at 5°C in samples
treated with 1.5% NaCl.
NaCl was not required by P. putrefaciens but both the growth
and DMDS production were stimulated by 1-2% of NaCl.
The DMDS production and the growth of P. putrefaciens were
reduced when the homogenate was treated with sodium benzoate (SB)
or ethylenediaminetetraacetic acid (EDTA). The maximum levels of
DMDS in 0.05% SB treated fish were 0.75 μg per 100 g and 0.85 μg
for 0.05% EDTA treatment, respectively.
The SB inhibited the growth rate as well as the maximum
growth of P. putrefaciens, while EDTA had no effect on the maximum
growth but extended the lag period and reduced the rate of growth.
Potassium sorbate (PS) had little effect on DMDS production or the
growth of P. putrefaciens. The maximum level of DMDS in fish
homogenate, treated with 0.1% PS, was 1.80 μg per 100 g and the
growth curve was similar to that of the control. / Graduation date: 1974
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26952 |
| Date | 12 April 1974 |
| Creators | Rhee, Kie Ho |
| Contributors | Lee, Jong S. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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