SEM may occur naturally

10 February 2011

European and Bangladeshi scientists are suggesting that semicarbazide (SEM), the metabolic marker used to detect the illegal antibiotic nitrofurazone, may occur naturally in the shell of crustaceans. The research was prompted by the Belgian authorities rejecting several consignments of Bangladeshi giant freshwater prawns (Macrobrachium rosenbergii) in 2009. It was presented at a symposium organised by the Seafood Importers and Processors Alliance (SIPA) and the Bangladesh Shrimp and Fish Foundation (BSFF) in Belgium.

Dr Christof van Poucke (Ghent) and Dr Glenn Kennedy (Belfast) presented their findings in laboratory grown prawns in the Ghent based Laboratory of Aquaculture and wild caught freshwater prawns from Bangladesh. Both studies conclude that semicarbazide is present as a natural component, primarily in the shell of the animals. Moreover, the studies show that SEM was present as a natural component of all the crustacean species tested, which included crabs, langoustines and shrimps. Although the metabolic route for its production in the animals cannot be confirmed yet, a role in protein synthesis is thought to be one of the possibilities.

A possible solution, suggested by Dr Kennedy, would be to analyse the inner core of the testing animal's meat, because the semicarbazide detected in wild-caught shrimp seemed to be surface-associated and the semicarbazide concentration in the inner meat was always well below the EU Reference Point for Action (=1μg/kg as described in EU regulation 470/2009/EC).

The presentations are available here: http://www.asemaquaculture.org/content/view/55/47/

For more information contact -
Ivan Bartolo
e: i_bartolo@seafish.co.uk
t: 01422 846740