First:
Their asking and then choosing to search is not about YOUR feelings, it's about them doing a job and having to make a choice based on a wide range of observations. Funny how it is so upsetting for an old white guy to be singled out of a line for a more indepth scrutiny about a bag of fruit. "Oh the horrors! They think I'm lying!"
Second:
If they let someone else take that fruit (or firewood, etc.), it will very likely find it's way into the state. Or will be dumped a few miles away when found to be infested with a bug and that bug will find its way over the state line. And if that happens, then the ag folks didn't do their job.
In the end, just deal. If they ask to search, say yes or no (whatever your reason) and politely deal with the consequences. Get over yourself.