I believe humans have a right to know where their food is grown, the processes and chemicals utilized, how old the food is, and basically everything possible about the item they will put into their bodies as fuel.
Many fruits and vegetables have stickers or UPCs affixed to them already. Just make them QR codes designed to track the above information. It's not any different than a UPS tracking code, but it would include additional information than just location. For example, if your food is treated with radiation or other methods, those would by law need to be included in your food's track. You can scan any piece of food in any store and see that food's history - Where it has been and how long it was there for - when it was harvested. Everything.
It's the way of the future, man. I'm telling you it's the way of the future.