The effect of washing machine separated rockfish flesh on
composition, quality and desirability was investigated.
Washing machine separated rockfish flesh resulted in a
36.88% loss of solids. The greatest reductions were found in the ash
(80.32%) and lipid (65.13%) levels in the washed flesh. Most of the
sarcoplasmic proteins were lost during washing and only 77.29% of
the protein (N X 6.25) was recovered.
Washing the machine separated fish flesh did not appreciably
alter the amino acid composition. The content of essential amino
acids of the drum-dried treatments was similar to casein and this
was reflected by the high protein efficiency ratios compared to the
casein reference. The mineral composition of the unwashed machine
separated flesh was similar to that of the fillet. Washing the machine separated flesh greatly altered the mineral composition in the flesh.
The levels of calcium, magnesium, barium, strontium, boron, and
manganese were not appreciably altered by washing. Phosphorus,
potassium, and sodium levels were reduced while the iron, copper,
zinc and chromium levels were increased in the washed flesh.
The rapid formation of trimethylamine (TMA) in the drumdried
rockfish fillet and unwashed machine separated flesh treatments
may be related to the development of off-odors and off-flavors formed
during storage at 30°C. The over-all desirability of bland wafers
consisting of 10% drum-dried washed flesh increased slightly during
storage but was not appreciably higher than the wafers containing the
drum-dried fillet and unwashed fish flesh. Over-all desirability may
not be directly linked to the formation of trimethylamine (TMA) since
washing drastically reduced the level of trimethylamine oxide (TMAO)
in the washed flesh and the subsequent formation of trimethylamine
(TMA) during storage at 30°C.
The much higher levels of malonaldehyde found in the drumdried
washed machine separated rockfish flesh may implicate the
oxidation of the lipids as being responsible for the lower over-all
desirability of the washed flesh. The rapid formation of malonaldehyde
may also indicate that naturally occurring antioxidants are
leached from the flesh during the washing process. / Graduation date: 1976
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26191 |
| Date | 19 January 1976 |
| Creators | Adu, Gloria Aderemi |
| Contributors | Babbitt, Jerry Keith, 1943- |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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