European and Bangladeshi scientists are suggesting that semicarbazide — the metabolic marker used to detect the illegal antibiotic nitrofurazone — may occur naturally in the shell of crustaceans.
The research — presented by the Europe-based Seafood Importers and Processors Alliance (SIPA) and the Bangladesh Shrimp and Fish Foundation (BSFF) at a symposium in Belgium on 24 November — was prompted by the presence of semicarbazide in Bangladeshi giant freshwater prawns (Macrobrachium rosenbergii). It resulted in more than 50 alerts being issued by the European Union’s Rapid Alert System for Food and Feed (RASFF) in 2009 after semicarbazide levels exceeding 1 part per billion were detected.
Studies conducted independently by Dr. Christof van Poucke of Ghent University in Belgium and Dr. Glenn Kennedy of the Agri-Food & Biosciences Institute in Belfast, United Kingdom, concluded that semicarbazide was present as a natural component in the freshwater prawns tested, found primarily in the shell. In fact, semicarbazide was present as a natural component in all of the crustaceans tested, including crabs and langoustines.
Although the metabolic route for semicarbazide’s production in the animals can’t be confirmed yet, protein synthesis is among the possibilities, said the scientists.
Dr. Jaap Hanekamp of the Global Harmonisation Initiative (GHI) said the advent of technology enabling measurement of chemicals at levels below the ecological chemical thresholds is the cause of the problem. According to GHI, food-safety legislation on human exposure to low levels of illegal chemicals should be toxicology-driven, not technology-driven.
Bangladeshi officials added during the symposium that they are working to improve regulation and control of the use of veterinary drugs in aquaculture, including expanding laboratory capacity and developing a traceability system.
The symposium was facilitated by the Asia-Europe Meeting (ASEM) Aquaculture Platform, and the research is available on the organization’s website.
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