Seasonal distribution of bromophenols in selected Hong Kong seafood

Selected seafood including rabbitfish (Siganus canaliculatus), brown-spotted grouper (Epinephelus areolatus), clam (Tapes philippinarum), oyster (Ostrea rivularis), shrimp (Penaeus japonicus), and crab (Charybdis feriatus), commonly found in the Hong Kong wet market, was monitored for their distribution and seasonal variations of their bromophenol contents. Specifically, 2-bromophenol (1), 4-bromophenol (2), 2,4-dibromophenol (3), 2,6-dibromophenol (4), and 2,4,6-tribromophenol (5) were monitored due to their flavor impact to seafood. All samples of marine origin contained bromophenols throughout a year. Crab had the highest concentration of total bromophenol content throughout the season. Concentrations of compounds 1, 4, and 5 in the local seafood were generally higher than that found in the literature values to provide characteristic flavor, but lower than that required to cause off-flavor. Variations of the flavor impact of bromophenols in seafood during a season could be better shown by their flavor values. Distribution and seasonal variations of bromophenol content in seafood coincided well with the seasonal growth cycle of the bromophenol synthesizing seaweeds, e.g. brown algae, in the region suggesting the abundant source of bromophenols in the environment might have a high impact on the quantity of bromophenols found in seafood.