Fig 1.
EU legislation relevant for production and marketing of organically produced eggs (for further details please see S1 Table).
Fig 2.
Theoretical design of a blockchain-based traceability chain for organically produced eggs.
Upper panel: Steps involved in adding information to the blockchain. Transactions are added to the transaction pool and attain the status of ‘confirmed’ during the consensus process. Confirmed transactions are added to the blockchain. Lower panel: Schematic implementation of the blockchain concept in the egg supply chain. According to EU law, only units 1, 3 and 5 will possess certificates as these are issued by the inspection bodies for organic produce to any farm that produces, prepares, stores or imports organic products from a third country or places them on the market [25]. The purchasing retailer and the transport units, if these are independent entities, therefore have no certificates of their own that would need to be considered in the blockchain.
Fig 3.
Issuing soulbound tokens (SBT) as certificates to regulate the status of each actor involved in control.
The scheme shown assumes emission of soulbound tokens for control of organic produce by the European Commission to the member states as the top-level authority. This concept is in line with ongoing efforts surrounding the European Blockchain Services Infrastructure.