The same way you verify it now. The technology does not change the process of physically inspecting the product. It makes it far easier to coordinate the paperwork of certifying and verifying.

At it's heart logistics is a global concurrency problem. The "locks" we use now are large sprawling bureaucracies that manually coordinate the transfer of information among many independently moving agents. Getting information into and out of this organization is a tedious, labor-intensive, and time consuming process. The technology that empowers cryptotokens is an alternate computerized concurrency management for this kind of information transfer and lookup that doesn't rely on a central organization or system.

Ok, but if _someone_ is certifying who can and who cannot write to the blockchain, why wasn't this solved 2 decades ago with that someone running a database with an API front-end that all involved parties can use?