Postharvest handling practices and the development of histamine in Giant Trevally (Caranx ignobilis) fish: The case of Fiji

Abstract

The study aimed at assessing the post-harvest handling practices of artisanal spear-gun fishers in Fiji and its impact in the development of histamine. The study employed in-depth interviews of artisanal fishers on their postharvest handling practices, and its relationships in the development of histamine in Giant Trevally (Aranxignobilis) fish. The Giant Trevally fish were further exposed to three different temperatures; 0°C, combination of 5°C and 28°C, and 28°C prior to histamine determination. Results revealed that spear-gun fishers do not normally ice their fish and rarely gut their catch during the fishing trips. However fish are only iced when received by middlemen and vendors once fish arrive at the landing sites, when stored in the recycled freezer containers. Fish are usually displayed un-gutted without ice on drained and tiled stalls, however used ice at the landing site are further reused to cool fish stored in the recycled freezer containers (above 5°C) alternatively every 2 h throughout the day for display on the counters (28°C) for sale. Any unsold fish are returned into the recycled freezer containers for sale the next day. Histamine determination revealed that after 35 h postharvest i.e. further storage at 0°C and at combination temperatures of 5°C and 28°C (recycled every 2 h) the histamine levels went below the Food Drug Administration (FDA) permitted levels (50 ppm). However, fish stored at 28°C had increased histamine concentration levels up to 193.2 ppm of 15 h post-harvest. The study demonstrated the importance of time and temperature control at postharvest handling of fish in tropical countries.