I did have a startup in the food industry for a while. We had to constantly cut off suppliers for counterfeit goods. One asked us what our budget was and offered a cheaper "AAA alternative" (code work for counterfeit).
A friend left the honey trading business because it became too troublesome to keep track - suppliers would mix a little sugar water into it, which they could tell, but customers couldn't. Things like stevia or milk often had a little water added on. As much as we blacklist companies that add water to 'fresh milk' they're top sellers because of the lower price. Parmesan is also commonly counterfeited and mixed with MSG or something.
I'm not sure American goods are much better, but at least everything is what it says on the label.
Over the years, things like this happened to serve as anecdotal data points:
* https://www.latimes.com/world/la-xpm-2013-feb-28-la-fg-china... * https://www.theguardian.com/money/2015/jul/02/cross-border-b...
lots more in other articles that are google-able.