@Roz4 I just posted about this myself...if you're like me and have back to back guests, this indeed may be why they are asking about the cooking. They may say something along the lines of "Well, we did ask about this..." if you complain when in fact they weren't actually being direct. Honestly, I would wonder too, especially if you've given a detailed description of the kitchen.
I'm in a bit of a quandary about this myself since I've had it happen that incoming guests have complained about the smell. If you can, when you meet them, maybe ask them what they were planning on cooking and ask them not to cook anything aromatic during their last 24 hours? You could ask if their cooking is "spicy" for example. I'm actually thinking of putting a little note up in my kitchen to this effect. I don't have a through breeze in my condo and so smells are hard to move, even with a good ventilation system. My last guests, who just left this afternoon, clearly made fish right before they left. My cleaner came in and right away commented on the smell. I'm wondering whether or not to mention their "aromatic" cooking in their review. The fact is that incoming guests can review us down on this issue, so it's important.