Investigating the Ability of Spice Extracts to Inhibit Bacterial Growth and/or Histamine Accumulation Associated with Scombroid Food Poisoning

Abstract

Feseekh, a fermented fish dish, is eaten the Monday following Easter. When feseekh fermentation produces unsafe histamine levels, consumption causes scombroid food poisoning. Many bacteria have been implicated, including Morganella morganii, the bacterium used in this study. This study’s purpose was to determine whether spices normally used in this fermented dish influence bacterial growth and histamine accumulation. Spice extracts were used in a disk diffusion assay with results showing no spice-induced growth inhibition. Next, histamine levels were measured in laboratory medium and in fish fermentations. No statistical differences in histamine were observed. Closer examination of the data revealed complicating issues. Extracts showed high background, suggesting they may contain confounding enzymes. Additionally, the low histamine levels, in combination with the high variability in the assay, may have disguised inhibition effects. Future directions include the use of direct assays to determine histamine levels and the use of fresh fish in fermentations.