2,6-dibromophenol: the cause of an iodoform-like off-flavour in some Australian crustacea

2,6‐Dibromophenol was identified as the cause of an iodoform‐like off‐flavour in the endeavour prawn, Metapenaeus endeavouri. In prawn meat this compound was detected by its characteristic flavour at a concentration of only 60 ng kg−1. However, quantitative analyses by gas chromatography‐multiple ion monitoring‐mass spectrometry of extracts of whole off‐flavoured prawns showed that, in some samples of this species, the concentration of this compound exceeded 200 μg kg−1. In addition, marine algae and bryozoa, which probably contribute to the diet of the endeavour prawn, were shown to contain the off‐flavour compound in comparable concentrations. 2,6‐Dibromophenol was also identified as the cause of an iodoform off‐flavour in the eastern king prawn, Penaeus plebejus. Furthermore, this compound was shown to be present in relatively low concentrations in five species of prawn not usually affected by this problem. 2‐and 4‐Bromophenol, 2,4‐dibromophenol and 2,4,6‐tribromophenol were also identified in all species of prawn examined. Handling and processing procedures which could reduce the severity of the off‐flavour in susceptible species are described.