Prestidigitation vs spot/ knowledge checks

[CyberThread]

What sort of bonus do you think prestidigitation would give against a spot or knowledge check on a certain item being poisonous, or somethings taste being altered?

[(Un)Inspired]

Is give it a +5 and I'd let the caster make a check to hide it more.

For instance if the cast was trying to hide something in food I'd let them make a craft: food or profession: chef check to fiddle with the dish to better disguise the flavor.