Brown seaweed as a food ingredient contributing to an adequate but not excessive amount of iodine in the European diet. A case study with bread.

Background: The large amounts of iodine in brown seaweeds may contribute towards an adequate iodine intake, but also pose a food safety risk. In the current work we estimate the maximum amount of the cultivated brown seaweeds Saccharina latissima and Alaria esculenta (blanched and non-blanched) that can be added to white loaf-type wheat-bread so European consumers are protected against excessive chronic intakes. We use data for high-level consumers of bread with special ingredients added from the EFSA comprehensive European food consumption database to construct a conservative risk management model. We bake prototype seaweed bread and use the output from the model to assess exposure to iodine and trace metals. We also assess some bread quality parameters such as sensory characteristics, crumb firmness and specific volume.

Results: The maximum level of iodine in bread that would mitigate the European consumer from excess intakes was 857 μg I kg bread. Assuming a typical 60% wheat flour per kilogram of bread, a maximum amount of 11.3 g of dried blanched A. esculenta (115 mg I kg dry weight) could be incorporated per kilogram of wheat flour into the bread recipe whilst for non-blanched S. latissima, which contained 3500 mg I kg dry weight, only a minuscule 350 mg of seaweed was the limit. For prototype breads, seaweed addition had no significant impact on the specific volume and crumb firmness. Levels of cadmium and arsenic in the bread were also of low toxicological concern.

Conclusion: A maximum 1-2% brown seaweed of total flour weight could be added to bread to contribute towards European consumers' adequate iodine intake without overexposure. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.