why why why?

Question

can anybody tell me why the following smell bad....and if possible provide any links for more information.

onion
garlic
liverwurst
durian
viex boulogne

thanks its for my science project.

and im not saying that it smells bad, but it does have a strong stench that is not really easy per-say to get off.

Answer 1

The smell of onions & garlic (I don't think that they smell bad;can't imagine some dishes without them!) is due to sulfur compounds.
Food chemistry can get rather complex. My opinion: Unless you're well versed in organic chemistry, you've grabbed a tiger by the tail with this topic.
Very interesting , but could prove to be very difficult.
http://www
.albany.edu/main/features/2002/12-02/block/chemistrygarlic.jpg