Dear Tim and Listers
In response to the query by Tim Koester on TVB.
I attach as a file that part of lecture notes of mine on chemical methods
for measuring freshness of fish dealing with TVB. The file is in .rtf format
so should be readable in any word processor. Bearing in mind Pamela's recent
comment on viruses, I have Norton antivirus software installed on my system.
There is a very large literature on TVB in fish, probably 3-400 references
make some reference. It has been applied to a very large variety of fish
species, vertebrate and invertebrate. Apart from the distillation procedures
summarised in my notes, methods based on other principles have been
described claiming some advantage over the simple distillation ones. Despite
all this effort, TVB is, and always will be, a very poor indicator of
freshness of fish. I can not be used reliably for quality assurance of fish
products for retail sale. TVB does not increase until the fish is past its
good quality condition and near its unfit for consumption stage. It is
included in an EU Directive, but in my opinion that inclusion could only
have been a political decision rather than one based on its merit -
hypoxanthine or inosine monophosphate contents, or K value are much better.
Try the following references for studies on reliability of TVB measurement,
and brief, but good, reviews - by Oehlenschläger - of its application and
limitations.
Peter Howgate
Antonacopoulos, N. & Vyncke, W. (1989). Determination of volatile basic
nitrogen: a third collaborative study by the West European Fish
Technologists' Association (WEFTA). Zeitschrift für
Lebensmittel-Untersuchung und -Forschung, 189, 309-316
Oehlenschläger, J. (1992). Evaluation of some well established and some
underrated indices for the determination of freshness and/or spoilage of ice
stored wet fish. In: Quality Assurance in the Fish Industry, H.H. Huss, M.
Jakobsen & J. Liston, eds, Elsevier Science Publishers, Amsterdam, pp
339-350. ISBN 0 444 89077-7
Oehlenschläger, J. (1992). Suitability of ammonia, dimethylamine,
trimethylamine, trimethylamine oxide and TVB as freshness indicators in
seafoods. In: Methods to determine the freshness of fish in research and
industry. Proceedings of the final meeting of the concerted action"
Evaluation of fish freshness" AIR3CT94 2283. (Edited by Ólafsdóttir, G.,
Luten, J., Dalgaard, P. Careche, M. Verrez-Bagnis, V. Martinsdottir, E. &
Heia, K.). Pp92-99. International Institute of Refrigeration, Paris. ISBN
2-9033633959.
Vyncke, W. (1996). Comparison of the official EC method for the
determination of total volatile bases in fish with routine methods. Archiv
für Lebensmittelhygiene, 47, 110-112
Vyncke, W., Luten, J., Brünner, K. & Moermans, R. (1987). Determination of
total volatile bases in fish: a collaborative study by the West European
Fish Technologists ' Association (WEFTA). Zeitschrift für
Lebensmittel-Untersuchung und -Forschung, 184, 110-114
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