Abstract
The present work was carried out to investigate the role of luminous bacteria, particularly Photobacterium spp, in relation to histamine formation in different parts of the body when mac-kerel are stored at low temperatures.
In the viscera of mackerel, Photobacterium phosphoreum increased but Photobacterium leiognathi decreased during subsequent storage in ice and at 10°C. In the skin, only P. phosphoreum was isolated during storage at 10°C, and comprised 33.2% of the flora. In the inner muscle, luminous bacteria were not detected and total viable counts (TVC) were extremely low. Increase of histamine during storage at 10°C was high in the outer muscle and viscera of fish but low in the inner muscle of fish separated from the viscera. The relationship between TVC with luminous bacteria were not detected and histamine content never correlated in every body part. It is, however, apparent that P. phosphoreum plays a part in histamine formation in stored fish. Moreover, strains of P. phosphoreum isolated from mackerel form large amounts of histamine during incubation in pure culture in ice.
It is considered that histamine found in the inner muscle of scombroid fish may be formed principally by diffusion from the viscera and body surface of mackerel.
