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Zlatina Peteva Mona Stancheva Stanislava Georgieva Bernd Krock Anelia Gerasimova-Peneva


Mussels accumulate marine biotoxins (phycotoxins) produced by certain phytoplankton species. In EU are set limits for toxin concentration (e.g. domoic acid, okadaic acid, yessotoxins etc.) beyond that mussels are safe for consumption. Marine biotoxins tend to accumulate in the digestive gland (hepatopancreas) of the mussel. Consequently, this tissue is preferred for toxin concentration determination. Normally the whole shellfish is consumed and therefore the occurrence data for phycotoxins need to be expressed in terms of whole shellfish meat. A theoretical factor of 5 is used to convert the value to whole shellfish meat. The aim of this study was to determine an empirical factor in order to convert phycotoxin concentrations from hepatopancreas to whole shellfish meat of main marine aquaculture in Bulgaria- mussels Mytilus galloprovincialis. Wild and cultivated mussels were collected from the north Black Sea coast of Bulgaria in 2017. In total 13 mussel samples were studied whereas in each sample subsamples of hepatopancreas only and whole mussel meat are prepared. Phycotoxins were extracted for all types of phycotoxins by means of liquid-liquid extraction and their concentration was determined via LC/MS. Yessotoxins appeared in most of the samples and therefore seemed most suitable for empirical conversion factor determination. It is calculated as ratio between determined concentration in hepatopancreas and whole shellfish meat. Mean defined value was 5.36. Determination and application of empirical conversion factor is important when establishing very low concentration for chronic exposure assessment. It will be advantageous when taking into account interspecies differences and to avoid phycotoxin omission if preparing whole shellfish sample.

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Aasen, J., Samdal, I., Miles C., Dahl, E. Yessotoxins in Norwegian blue mussels (Mytilus edulis): uptake from Protoceratium reticulatum, metabolism and depuration. Toxicon. 2005, 45: 265-272.

Alfonso, A., de la Rosa, L., Vieytes, R. Y. Yessotoxin, a novel phytotoxin, activates phosphodiesterase activity: effect of yessotoxin on cAMP levels in human lymphocytes. Biochem. Pharmacol. 2003, 65: 193-208.

Alves-de-Souza, C., Varela, D., Contreras, C., de La Iglesia, P., Fernández, P. Seasonal variability of Dinophysis spp. and Protoceratium reticulatum associated to lipophilic shellfish toxins in a strongly stratified Chilean fjord. Deep Sea Res. 2013, 101: 152-162.

Aune, T., de la Rosa, L., Vieytes, M., Yasumoto, T., Botana, L. Yessotoxin, a novel phytotoxin, activates phosphodiesterase. Biochem. Pharmacol. 2003, 65: 193-208.

Bricelj, V., Shumway, S. Paralytic shellfish toxins in bivalve mollusks: occurrence, transfer kinetics, and biotransformation. Rev Fish Sci. 1998, 6: 315-383.

Burrow, R., Seamer, C. A Guide for the Evaluation of New Test Methods-Shellfish Quality Assurance Programme. Wellington, New Zealand: Ministry of Agriculture and Forestry (MAF) Food Assurance Authority. 2017, 1-18.

Callegari, F., Rossini, G. Yessotoxin inhibits the complete degradation of E-cadherin. Toxicology. 2008, 244: 133-144.

de la Rosa, L., Alfonso, A., Vilariño, N., Vieytes, M. B. Modulation of cytosolic calcium levels of human lymphocytes by yessotoxin, a novel marine phycotoxin. Biochemical Pharmacology. 2001, 61: 827-833.

BAFS. Register of aquaculture production sites until 15.07.2017 [In Bulgarian].

Edebo, L., Lange, S., Li, X., Allenmark, S. Seasonal, geographic and individual variation of okadaic acid content in cultivated mussels in Sweden. Acta Pathologica Microbiologica Scandinavica Series C: Immunology banner. 1988, 96(7-12): 1036-1042.

EFSA. Marine biotoxins in shellfish -okadaic acid and analogues. The EFSA Journal. 2008a, 589: 1-62.

EFSA. Marine biotoxins in shellfish-Azaspiracid group. The EFSA Journal. 2008b, 723: 1-52.

EFSA. Marine biotoxins in shellfish – Yessotoxin group. The EFSA Journal. 2008c, 907: 1-62.

How to Cite
PETEVA, Zlatina et al. Empirical determination of conversion factor for depicting phycotoxin concentration in whole mussel Mytilus galloprovincialis meat. Food Science and Applied Biotechnology, [S.l.], v. 2, n. 2, p. 166-174, oct. 2019. ISSN 2603-3380. Available at: <>. Date accessed: 18 may 2024. doi: