There are customs regulations against importing foodstuffs in many areas. For international travel or shipping, this might prove problematic on those grounds.

Rice, for example, is not allowed or might require specific permission to import into Australia. Coffee, noodles, pasta, pepper, and wheat might be restricted.

https://www.abf.gov.au/entering-and-leaving-australia/can-yo...

If you are just getting package disturbed 100% of the time by TSA, that makes it useless to detect whether or not somebody else also tampers with it.