The assumption is that a preserved burger means it's full of nasties, but the truth is rather different, as food technologist, Gary Kennedy, explains.
James Valentine and HG Nelson cast their expert eyes over planning.
Ange Lavoipierre and Sam McCool tackle this week's questions penned by Matt Bevan and James Valentine.
You'll meet people who lost their sense of smell and got it back. Others have a highly attuned sense of smell and can detect all manner of things.
This week, Greta Thunberg Helpline viral sensations, Charles Firth and Ange Lavoipierre go head to head.