Saw this recently:

http://cookingonabootstrap.com/2016/02/08/dont-throw-that-away-an-a-z-of-leftovers-tired-veg-etc-and-what-to-do-with-them/

and couldn’t believe the inventiveness! I had no idea about the lemons! I’ll definitely be trying that out..

Meanwhile, if any fruit/veg really have gone past human (or guinea pig) consumption, the compost heap will love you for it!