WikiMedia API - How to determine which portal(s) a Page belongs to?

I wish to determine whether a given Wikipedia page belongs to a certain Wikipedia Portal using the MediaWiki API. So far, I have been experimenting with the page properties of the API but I cannot seem to find a way to derive what Portal a given page belongs to.

As an example, on the Wikipedia page for Cake in the very bottom of the page, I can press Show on the section Cakes, and a bunch of links to different cake pages show up. There I can also see that all of these belong to the Food portal. It is that information that I would wish to extract from a given page using the MediaWiki API.

As far as I know, there is actually no formal definition of "belongings to a portal" in Wikipedia. Opposed to categories which are part of the MediaWiki software, portals are custom pages for Wikipedia that are aimed to make it easier to explore a topic.

Instead of a formal definition though, you can use an heuristic and determine the connection between the page and some portal based on one of them linking to the other. There are API endpoints for both:

(Note: 100 is the id of the 'Portal` namespace)

Which portal pages are linked from the page "Cake" or "Pizza"

https://en.wikipedia.org/w/api.php?action=query&format=json&prop=links&titles=Cake%7CPizza&plnamespace=100

Which portal pages link to the page "Cake" or "Pizza"

https://en.wikipedia.org/w/api.php?action=query&format=json&prop=linkshere&titles=Cake%7CPizza&lhnamespace=100
(though as you can see, many unrelated portals link to "Cake" and none link to "Pizza")

A combined query for both directions

https://en.wikipedia.org/w/api.php?action=query&format=json&prop=links%7Clinkshere&titles=Cake%7CPizza&plnamespace=100&lhnamespace=100