%0 Journal Article %T Theoretical design of blockchain-based traceability for organic egg supply chains according to regulation (EU) 2018/848. %A Zülch F %A Holle M %A Hofmann A %J PLoS One %V 19 %N 6 %D 2024 %M 38861508 %F 3.752 %R 10.1371/journal.pone.0304791 %X The use of blockchain technology to establish food traceability chains has the potential to provide transparent information of food stuffs along the entire supply chain and also aid in the documentation or even execution of official food control processes. Particularly in instances where analytical methodologies cannot provide definitive data for food control questions under study, the certificate-based approach of a traceability chain may offer a way of regulatory control for state authorities. Given the rising importance of organic produce and the high share of eggs among the organic produce in the European Union as well as the new EU regulation on organic products and labelling that came into force in 2022, we analyze here how the control of egg production type and marketing standards can be represented within a blockchain-based traceability chain such as to maximize the traceability in compliance with the current relevant EU regulations. Intended for the use by the official food control authorities, a traceability chain for organically produced eggs in the EU would need to be implemented as a permissioned blockchain, since only select entities are allowed to participate. By combining a proof of authority consensus mechanism with issuance of soulbound tokens, we effectively suggest a 'proof of soulbound authority' consensus process. The soulbound tokens are issued throughout the administrative chain from the European Commission down to the official food control authorities in individual member states that ultimately certify the control bodies for organic produce. Despite the general limitation of not providing unambiguous proof of the organic status of individual products, the concept discussed here offers advantages with respect to allocation of authority at EU level and therefore might have positive effects beyond the traceability chain.