Background: The present study determined the heavy metal contamination (mercury, cadmium, lead, arsenic and nickel) of nori, restaurant-served sushi and ready-to-eat sushi meals available via retail chains. Moreover, both microbiological load and biogenic amine content in ready-to-eat sushi meals were analysed.
Results: All of the nori samples contained high levels of Cd (2.122 mg kg-1 ), Ni (0.715 mg kg-1 ), As (34.56 mg kg-1 ) and Pb (0.659 mg kg-1 ). The studied sushi samples contained high levels of Ni and Pb, reaching 0.194 and 0.142 mg kg-1 wet weight, respectively, being potentially hazardous to women during pregnancy and lactation and small children. None of the studied samples contained high levels of Hg. Overall, 37% of ready-to-eat sushi meals exceeded a microbiological load of 106 cfu g-1 . However, biogenic amine content in all of the samples was low, with a highest histamine content of 2.05 mg kg-1 .
Conclusion: Sushi is not the source of high levels of biogenic amines even with high microbiological loads. Nevertheless, the high microbiological loads at the end of the shelf-life indicate that some processors might have problems with the distribution chain or implement a poor hygienic regime. Moreover as a result of possible risk associated with heavy metal contamination, the present study highlights the need to establish new regulations regarding the contamination of nori and sushi. © 2017 Society of Chemical Industry.
Keywords: biogenic amines; heavy metals; nori; sushi; total viable count.
© 2017 Society of Chemical Industry.