I can't help you with Knoxville proper, but if you have time, you need to hit up
Benton's Smoky Mountain Country Hams in Madisonville, TN. It's roughly 30 minutes southwest of Knoxville and not too far off of I-75. Whenever I have to go to or through Knoxville, I make it a point to stop there. They make the best bacon I've ever had and it's not even close. But you don't need to take my word for it. Benton's street cred abounds:
https://www.forbes.com/sites/leslie...-advice-from-the-worlds-greatest-bacon-maker/
https://www.saveur.com/article/Travels/Behind-the-Scenes-at-Bentons-Country-Hams/
https://www.southernfoodways.org/interview/allan-benton/
http://www.gourmet.com.s3-website-us-east-1.amazonaws.com/magazine/2000s/2006/10/bentons-hams.html
The bacon's so well cured that it'll keep without refrigeration for a bit, but I'd lug a cooler along anyway just in case you want some of their ground sausage (which you'll have to ask for). Their prosciutto is also fantastic, as are their ham hocks (another out-of-sight item that you have to ask for).
There's also a dairy that's really close to I-75 and Benton's on the way to Knoxville that makes a nice stop --
Sweetwater Vally Farm. Lots of derivations of cheddar, along with jack and gouda. The smoked cheeses are nice, as are the spicy and sharp ones. They've got samples of everything, too, so that alone may be worth it if you're getting hungry on your way in or out of town.
Oh, and one last thing: if you're a wine or whisky drinker and live in a state without a
Total Wine, you should visit the one on the southern outskirts of Knoxville on your way into town. It's the biggest chain liquor store in the country and its prices and selection embarrass every other liquor store I've ever been to (at least in Tennessee). Plus, their entire inventory is available online for purchase, so you can shop from home and arrange to pick it up whenever you want. The store in Knoxville also has great "mixed case" discounts (9% on liquor and 16% on wine). That's exactly what it sounds like -- 12 bottles of any variety of the same size of wine or liquor gets you the discount. Went in on a mixed case of liquor with some buddies recently and I saved between 25% and 35% compared to prices at my local shops. (Examples: ~$40 for Woodford Double Oaked (which is fantastic, by the way) vs. ~$55 locally, $34 for Bushmill's 10 yr single malt vs. $50 locally, $40 Auchentoshan 12 yr vs. $50 locally.) There's also an interesting backstory to Total Wine's Knoxville location that ended with a
United States Supreme Court decision voiding a protectionist Tennessee liquor law as unconstitutional.