So can it be assumed that 'the orange' is 'appelsinen'?
Yep.
why do we use "ET æble" and "EN appelsin"?
"orange" the fruit is "appelsin"? That's not confusing...
In Dutch, it's "sinaasappel." You get used to it.
Or appelsien...
lol I don't get why you got so many down votes for "appelsien"... do people not like Flanders/Limburg? (maybe don't answer that)
Apparently we don't speak Dutch.
Very good observation