There is no such thing as "an item" moving through the food chain. In the EU we have a somewhat traditional system for cattle, created after the BSE crisis. Ea

There is no such thing as "an item" moving through the food chain. In the EU we have a somewhat traditional system for cattle, created after the BSE crisis. Each animal has two ear tags which contain a unique ID. This ID will be carried through to the table if necessary. But it has to be "copied" along, for example when the animal is processed. The idea behind block chains in food processing is to record the transactions between individual parties. The blockchain does not verify the food, but rather the belief that they passed on a certain product. A malicious party will now have much more problems creating, vanishing or forging material. It also doesn't matter that much, because after a malicious transaction the following transactions are perfectly traceable again (if at least those are honest...).