Is it so hard to understand that words can have different meanings in different circumstances? Context matters, words don't have one universal definition.
But this is an article intended for general readership, so it should use words as they are understood by general readers, or else point out that it is using a word in a non-general sense.
You're right that context matters. Which is precisely why this article is badly and misleadingly written, if the authors are ignoring the context of an average reader.
This isn't a food science journal for scientists, after all.
Fair enough, given the amount of confusion in the comments here it's clear that at the very least they should have explained the difference between rancidity in oils and the colloquial definition.
https://en.wikipedia.org/wiki/Rancidification
...except when it doesn't.
Is it so hard to understand that words can have different meanings in different circumstances? Context matters, words don't have one universal definition.