Changes in numbers of histamine-forming bacteria on/in common mackerel stored at various temperatures.

Abstract

In the previous paper, the authors reported that histamine-forming bacteria found in the fish samples were N-group bacteria, Proteus morganii, P. vulgaris, Hafnia alvei, Citrobacter spp., Vibrio spp., Aeromonas spp. and so on. This study was carried out on the changes in the numbers of histamine-forming bacteria on/in common mackerel samples stored at different temperatrues. In both cases of the samples stored at 5°C and 10°C, main histamine formers were only N-group bacteria. In the samples stored at 15°C, the formation of histamine might be attributed to the N-group bacteria, although P. morganii increased during the storage. As for the samples stored at 20°C, a great part of histamine at the early stage of the storage might be accumulated by the N-group bacteria and at the later stage by P. morganii. In both cases of the samples stored at 25°C and 30°C, the accumulation of histamine was due to the action of P. morganii to a great extent.