How to preserve jagged (without anti-aliasing) when exporting to PDF?

I created a jagged line drawing in Processing, than exported it to PDF. When I opened it in Illustrator it was fine (I turned anti-aliasing off). But after saving it to PDF and reviewing in Adobe Acrobat the anti-aliasing was back on.

Is there any way to preserve it? Or is it just Acrobat, that applies anti-aliasing when previewing? Is it possible to print it on paper in it's jagged format?

Thank you!