Done. Could someone explain the joke though? Maybe it has something to do with Minoriko's first spellcard?

Anthocyanin changes colour in different PH. Red in acidic environment, blue in basic. As the ripe pear is probably supposed to be reddish, Minoriko smashes it into "sour" person's face.

woah it was hard to understand at first...
but this pear look like an apple to me, it's a japanese pear or something like that ?

I think that's a mutant....a combination of apple and pear, called "apple-pear" if I'm not wrong.

Hahaha. It's not actually a mutant. The pyrus pyrifolia (Asian pear) are often called "apple pears" because of their appearance and because they have a crisp, apple-like texture. This would certainly appear to be one, though. If I had to just guess, it might be a Kosui variety?

Google helped me :)
Search results said that in certain old Touhou games, Marisa(魔理沙) was written 魔梨沙 as a mistake. And Marisa that time wore clothes of purple colour like 2nd panel. So I think a kanji 梨 reminded the author of these facts and this comic. So perhaps what the author truly tried to say is just last panel. If you can read japanese, search words "魔梨沙　黒歴史" may help you.

The linked wiki page also mentioned something about Anthocyanin having to do with plants attracting pollinators.

A MarixWrig fan, I guess?

nashi, japanese pears. theyre tasty

they grow in my region, too. I want to plant one but we have too many fruit trees already