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|Title: ||Effect of processing on histamine levels in mackerel|
|Authors: ||Al-Kasadi, Abdulla Saeed|
|Issue Date: ||1984|
|Publisher: ||© A.S. Al-Kasadi|
|Abstract: ||Histamine, which is produced by bacterial decarboxylation of
histidine in pelagic fish, is implicated in scombrotoxin poisoning.
This investigation was carried out to determine the effect of processing
on histamine levels in the flesh of mackerel (Scomber scombrus).
Two methods of determining histamine in fish samples were
evaluated. A calorimetric method, involving coupling of histamine to
give an azo-dye, was found to be simple and reliable and was used to
determine histamine levels in a large number of canned and salted/dried
fish samples. A gas chromatographic method was found to be unsuitable
for use in determining histamine at levels found in fish and fish
The stability of standard histamine solutions at different pH
values was investigated by subjecting to heat (121°C for 180 min).
This treatment showed a loss of less than 5%.
Various compounds (glucose, ribose, ascorbic acid and benzaldehyde)
that react with histamine, were added to standard histamine solutions to
investigate the possibility of decreasing histamine levels in canned
products. The' heat treated solutions showed a loss of histamine of less
than 10% and distinct browning occurred in the solutions containing
glucose and ribose.
The effect of heat treatment (115°C for 90 min) on histamine in the
presence of fish flesh was also examined. Variable results were
obtained with a mean loss of histamine of only about 16)\,. When this
experiment was repeated with the addition of glucose it gave a higher
loss of about 36%.
The effect of salting, drying and subsequent storage on the histamine
levels in mackerel was investigated. Increases in histamine were
observed during salting, drying and storage for both whole and gutted
fish, with greater increases in. general for whole fish. The increases
for both whole and gutted fish occurred under conditions in which
bacterial growth would be suppressed, indicating that another mechanism
of histamine formation might be operative.|
|Description: ||A Master's Thesis. Submitted in partial fulfilment of the requirements for the award of Master of Philosophy of Loughborough University.|
|Appears in Collections:||MPhil Theses (Chemical Engineering)|
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