Method To Highlight Any Cell That Contains Anything But Allowed Set Of Words

I have a data set containing text (no numbers) that spans several columns and rows. I have a list of 'allowed' words (about 100 words) that can be in these cells. If a cell contains a sentence with a word that is anything other than these allowed words it should be somehow marked. Ideally the 'wrong' word itself is marked, but it would already be very useful if the cell that contains the word is marked in some way.

I tried conditional formatting, but it seems to only allow formatting cells that contain a certain word, not if it doesn't contain certain words. Is there a function or a script that would be able to do this?

Simplified example:

Say you have four allowed words:
Apple
Pear
Orange
Banana

You have the following cells:

>Apple Banana
>Pear Pear Orange Pear
>Banana Apple Orange Kiwi

The third cell should be marked because it contains a word outside of the set.