Opening up food to the air does release a smell. Some foods more than others. Chewing would release some smell as well. My dog does come sniffing around when I am eating. Our zombies have a great sense of smell, just like my dog.
I found this Brave AI summary interesting:
"Dogs use their sense of smell to perceive the world in intricate detail. They can detect not only the presence of a scent but also its source, direction, and even the time it was deposited, as odors decay predictably over time. A single sniff can convey information about a person's gender, mood, health, diet, and emotional state. They can identify individuals, including family members and other dogs, even after years of separation, and can determine the social status and health of other animals through scent signals like urine marking. Dogs can also detect changes in human metabolism associated with diseases such as cancer, diabetes, and even COVID-19 with high accuracy, sometimes reaching 97% detection rates.
Dogs use their sense of smell for navigation, tracking, and survival. They can follow scent trails over long distances—bloodhounds have been known to track a trail for more than 130 miles—and can detect scents buried up to 40 feet underground. They can even identify human fingerprints that are a week old and detect cremated remains among ashes from a burned house. This remarkable ability has led to their widespread use in law enforcement, search and rescue, and medical detection, where they serve as mobile, highly sensitive chemical scanners."
