Could not chewing food properly result in bad breath?

Not really: Not cleaning your teeth properly (floss), infected tonsils/adenoids, or GI problems such as gerd, are the primary causes.

Yes, it may: The bad breath may differ during the day, due to eating certain foods like garlic, onions, meat, fish, cheese and and not chewing your food completely can cause you to have bad breath. Ask your dentist for more information.