Identification of processed tuna products sold by the Brazilian market

Resumo

The composition of processed food is a concern of consumers, of the fishery industry and governmental agencies. The specific composition of canned tuna in three Brazilian brands was evaluated using Single-Strand Conformational Polymorphism (SSCP) of the cytochrome b gene by comparison with patterns of fresh tuna samples and tuna-related species landed at Santa Catarina ports (South Brazil). Thirteen SSCP patterns were obtained from fresh samples, and the specific variety was confirmed by analyzing their sequences. Inconsistencies were found in the fishery statistics of Auxis thazard thazard and Scomber japonicus reported from Brazilian ports, where fresh samples instead were represented mostly by Auxis rochei rochei and Scomber colias. A case of introgression was detected between A. t. thazard and Katsuwonus pelamis. The skipjack tuna K. pelamis composed seven out of eight of the processed tuna products analyzed, and two brands showed products containing a mixture of tuna (K. pelamis or Thunnus albacares) and the less commercially valuable bonito meat (A. t. thazard), which reinforces the need for the control of canned tuna in the Brazilian market.