It is also present in high levels in the edible offal of animals, such as kidneys and livers.
In prawns these organs are found in the ‘head’ part – which is considered a delicacy in Italy and Spain.
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While the food eaten at Christmas and New Year in Italy can vary greatly from region to region, seafood often features heavily – especially in the south and islands.
The head is pulled off and sucked on before the body is peeled and the white meat consumed.