Carry cans home for preserving food (7)

'preserving food' is the definition.
The definition and answer can be both related to change as well as being present participle verbs.
Maybe there's an association between them I don't understand?

'carry cans home' is the wordplay.
'carry' becomes 'bring' (bringing is a kind of carrying).
'cans' indicates putting letters inside (to can could mean to contain).
'home' becomes 'in' ('he's home' can mean 'he's in').
'bring' enclosing 'in' is 'BRINING'.

'for' acts as a link.

Can you help me to learn more?