Walmart's food tracking 

Walmart's food tracking use case is a combination of blockchain and IoT to make a food product's history transparent and traceable to it's origin. It's an example of supply chain management on blockchain. Walmart's food tracking supply chain management is built on top of the Hyperledger Fabric platform.  

A lot of people die every year due to food poisoning. As soon as someone falls sick or dies due to food poisoning the authorities try to track the source of the food and make sure that all the food items from the source that are distributed is suspended from selling and is called back. This saves lives of a lot of people. But the issue is that as every participation in the supply chain have their own ways and processes storing and retrieving information therefore it takes weeks for the authorities to track the source prevent everyone in the chain from selling the food items. Blockchain in combination with the IoT might just be able to solve this problem.

With every party in the supply chain storing and retrieving information, blockchain can fasten the process of finding the source of a food item. The following list shows additional benefits blockchain can add:

• Consumers can see exactly where a food product was harvested.
• Due to panic over food poisoning, people tend to throw away clean food, which increases the amount of food wasted. Blockchain can pinpoint the tainted food, therefore preventing food waste.
• Each step in the supply chain is visible to everybody. Fraudulent food entering the market can be avoided.
• Blockchain can act as evidence that a tainted food items was shipped from a particular producer. Due to this, producers will take care and adhere to safe practices because, if they don't, they will be caught with the evidence.
• Finally every food item gets a story associated with it. This enables users to learn about the food item's history.

IoT technology, such as sensors and RFID tags, enables real-time data to be written on the blockchain as food products pass along the supply chain.

Let's see an example of what the blockchain records in this case, and who the participants are. The participants are farms from where the food originates, factories where they are packed and processed, cargo companies who ship the food, Walmart stores, and so on. The data recorded on the blockchain is farm origin data, the batch number, factory and processing data, expiration dates, storage temperatures, and shipping details.