Mercury content in the white and dark muscle of Skipjack tuna (Katsuwonus pelamis) along the canning process: Implications to the consumers

•Mercury (Hg) analysis was performed in white and dark muscle of Skipjack tuna fish.•Overall, dark muscle contains higher Hg concentration than white muscle.•Hg concentration increases significantly along the canning process.•Ingestion of this canned product does not represent a risk in terms of human diet.

Mercury (Hg) content behaviour was followed along the canning process in muscle samples of tuna fish to point out implications concerning canned tuna consumers. Hg was quantified in the same batch of the Skipjack tuna (Katsuwonus pelamis), considering three distinct stages (raw, cooked and canned tuna) independently in both white and dark muscle tissue. Hg concentration data was then used to estimate the weekly tolerable intake of Hg regarding the recommendations from the international agencies.A small but significant difference in Hg concentration between white and dark muscle was observed either in the raw samples (0.115 ± 0.003 μg g−1 against 0.124 ± 0.003 μg g−1) as also in the canned samples (0.134 ± 0.003 μg g−1 against 0.155 ± 0.003 μg g−1). Overall results indicate an increment in the Hg concentration in both types of muscle throughout the canning process (raw < cooked < canned), although being only statistically significant between raw and canned samples. However, regarding the limits imposed by international agencies, the consumption of the examined canned products, do not represent a risk in terms of human diet.

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