Heavy metal contamination, microbiological spoilage and biogenic amine content in sushi available on the Polish market

BACKGROUNDThe 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. RESULTSAll of the nori samples contained high levels of Cd (2.122mg kg(-1)), Ni (0.715mg kg(-1)), As (34.56mg kg(-1)) and Pb (0.659mg kg(-1)). The studied sushi samples contained high levels of Ni and Pb, reaching 0.194 and 0.142mg 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 10(6)cfu g(-1). However, biogenic amine content in all of the samples was low, with a highest histamine content of 2.05mg kg(-1). CONCLUSIONSushi 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. (c) 2017 Society of Chemical Industry